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UniProtKB - P17405 (ASM_HUMAN)

Protein

Sphingomyelin phosphodiesterase

Gene

SMPD1

Organism
Homo sapiens (Human)
Status
Reviewed-Annotation score:

Annotation score:5 out of 5

<p>The annotation score provides a heuristic measure of the annotation content of a UniProtKB entry or proteome. This score <strong>cannot</strong> be used as a measure of the accuracy of the annotation as we cannot define the ‘correct annotation’ for any given protein.<p><a href='/help/annotation_score' target='_top'>More...</a></p>-Experimental evidence at protein leveli <p>This indicates the type of evidence that supports the existence of the protein. Note that the ‘protein existence’ evidence does not give information on the accuracy or correctness of the sequence(s) displayed.<p><a href='/help/protein_existence' target='_top'>More...</a></p>

<p>This section provides any useful information about the protein, mostly biological knowledge.<p><a href='/help/function_section' target='_top'>More...</a></p>Functioni

Converts sphingomyelin to ceramide (PubMed:1840600, PubMed:18815062, PubMed:27659707, PubMed:25920558). Also has phospholipase C activities toward 1,2-diacylglycerolphosphocholine and 1,2-diacylglycerolphosphoglycerol.Curated4 Publications
Isoform 2 lacks residues that bind the cofactor Zn2+ and has no enzyme activity.Curated1 Publication
Isoform 3 lacks residues that bind the cofactor Zn2+ and has no enzyme activity.Curated1 Publication

Miscellaneous

There are two types of sphingomyelinases: ASM (acid), and NSM (neutral).

Caution

Variants Gln-294 and Val-485 have been originally reported as disease-causing mutations in NPDA and NPDB (PubMed:12369017, PubMed:15221801). These variants have been reclassified as benign polymorphisms (PubMed:23430512).3 Publications

<p>This subsection of the <a href="http://www.uniprot.org/help/function_section">Function</a> section describes the catalytic activity of an enzyme, i.e. a chemical reaction that the enzyme catalyzes.<p><a href='/help/catalytic_activity' target='_top'>More...</a></p>Catalytic activityi

<p>This subsection of the ‘Function’ section provides information relevant to cofactors. A cofactor is any non-protein substance required for a protein to be catalytically active. Some cofactors are inorganic, such as the metal atoms zinc, iron, and copper in various oxidation states. Others, such as most vitamins, are organic.<p><a href='/help/cofactor' target='_top'>More...</a></p>Cofactori

Zn2+1 PublicationNote: Binds 2 Zn2+ ions per subunit (PubMed:27349982, PubMed:27725636). Zn2+ is particularly important for enzyme activity at neutral pH (PubMed:8702487).3 Publications

Sites

Feature keyPosition(s)DescriptionActionsGraphical viewLength
<p>This subsection of the ‘Function’ section indicates at which position the protein binds a given metal ion. The nature of the metal is indicated in the ‘Description’ field.<p><a href='/help/metal' target='_top'>More...</a></p>Metal bindingi208Zinc 1Combined sources1 Publication1
Metal bindingi210Zinc 1; via tele nitrogenCombined sources1 Publication1
Metal bindingi280Zinc 1Combined sources1 Publication1
Metal bindingi280Zinc 2Combined sources1 Publication1
Metal bindingi320Zinc 2Combined sources1 Publication1
Metal bindingi427Zinc 2; via tele nitrogenCombined sources1 Publication1
Metal bindingi459Zinc 2; via pros nitrogenCombined sources1 Publication1
Metal bindingi461Zinc 1; via tele nitrogenCombined sources1 Publication1

<p>The <a href="http://www.geneontology.org/">Gene Ontology (GO)</a> project provides a set of hierarchical controlled vocabulary split into 3 categories:<p><a href='/help/gene_ontology' target='_top'>More...</a></p>GO - Molecular functioni

View the complete GO annotation on QuickGO ...

GO - Biological processi

View the complete GO annotation on QuickGO ...

<p>UniProtKB Keywords constitute a <a href="http://www.uniprot.org/keywords">controlled vocabulary</a> with a hierarchical structure. Keywords summarise the content of a UniProtKB entry and facilitate the search for proteins of interest.<p><a href='/help/keywords' target='_top'>More...</a></p>Keywordsi

Molecular functionGlycosidase, Hydrolase
LigandMetal-binding, Zinc

Enzyme and pathway databases

Reactome - a knowledgebase of biological pathways and processes

More...Reactomei		R-HSA-1660662 Glycosphingolipid metabolism

SIGNOR Signaling Network Open Resource

More...SIGNORi		P17405

Chemistry databases

SwissLipids knowledge resource for lipid biology

More...SwissLipidsi		SLP:000001748

<p>This section provides information about the protein and gene name(s) and synonym(s) and about the organism that is the source of the protein sequence.<p><a href='/help/names_and_taxonomy_section' target='_top'>More...</a></p>Names & Taxonomyi

<p>This subsection of the <a href="http://www.uniprot.org/help/names_and_taxonomy_section">Names and taxonomy</a> section provides an exhaustive list of all names of the protein, from commonly used to obsolete, to allow unambiguous identification of a protein.<p><a href='/help/protein_names' target='_top'>More...</a></p>Protein namesi
Recommended name:
Sphingomyelin phosphodiesterase (EC:3.1.4.126 Publications)
Alternative name(s):
Acid sphingomyelinase1 Publication
Short name:
aSMase
<p>This subsection of the <a href="http://www.uniprot.org/help/names_and_taxonomy_section">Names and taxonomy</a> section indicates the name(s) of the gene(s) that code for the protein sequence(s) described in the entry. Four distinct tokens exist: ‘Name’, ‘Synonyms’, ‘Ordered locus names’ and ‘ORF names’.<p><a href='/help/gene_name' target='_top'>More...</a></p>Gene namesi
Name:SMPD1
Synonyms:ASM
<p>This subsection of the <a href="http://www.uniprot.org/help/names_and_taxonomy_section">Names and taxonomy</a> section provides information on the name(s) of the organism that is the source of the protein sequence.<p><a href='/help/organism-name' target='_top'>More...</a></p>OrganismiHomo sapiens (Human)
<p>This subsection of the <a href="http://www.uniprot.org/help/names_and_taxonomy_section">Names and taxonomy</a> section shows the unique identifier assigned by the NCBI to the source organism of the protein. This is known as the ‘taxonomic identifier’ or ‘taxid’.<p><a href='/help/taxonomic_identifier' target='_top'>More...</a></p>Taxonomic identifieri9606 [NCBI]
<p>This subsection of the <a href="http://www.uniprot.org/help/names_and_taxonomy_section">Names and taxonomy</a> section contains the taxonomic hierarchical classification lineage of the source organism. It lists the nodes as they appear top-down in the taxonomic tree, with the more general grouping listed first.<p><a href='/help/taxonomic_lineage' target='_top'>More...</a></p>Taxonomic lineageiEukaryota › Metazoa › Chordata › Craniata › Vertebrata › Euteleostomi › Mammalia › Eutheria › Euarchontoglires › Primates › Haplorrhini › Catarrhini › Hominidae › Homo
<p>This subsection of the <a href="http://www.uniprot.org/help/names_and_taxonomy_section">Names and taxonomy</a> section is present for entries that are part of a <a href="http://www.uniprot.org/proteomes">proteome</a>, i.e. of a set of proteins thought to be expressed by organisms whose genomes have been completely sequenced.<p><a href='/help/proteomes_manual' target='_top'>More...</a></p>Proteomesi
  • UP000005640 <p>A UniProt <a href="http://www.uniprot.org/manual/proteomes_manual">proteome</a> can consist of several components. <br></br>The component name refers to the genomic component encoding a set of proteins.<p><a href='/help/proteome_component' target='_top'>More...</a></p> Componenti: Chromosome 11

Organism-specific databases

Eukaryotic Pathogen Database Resources

More...EuPathDBi		HostDB:ENSG00000166311.9

Human Gene Nomenclature Database

More...HGNCi		HGNC:11120 SMPD1

Online Mendelian Inheritance in Man (OMIM)

More...MIMi		607608 gene

neXtProt; the human protein knowledge platform

More...neXtProti		NX_P17405

<p>This section provides information on the location and the topology of the mature protein in the cell.<p><a href='/help/subcellular_location_section' target='_top'>More...</a></p>Subcellular locationi

Extracellular region or secreted Cytosol Plasma membrane Cytoskeleton Lysosome Endosome Peroxisome ER Golgi apparatus Nucleus Mitochondrion Manual annotation Automatic computational assertionGraphics by Christian Stolte; Source: COMPARTMENTS

Keywords - Cellular componenti

Lysosome, Secreted

<p>This section provides information on the disease(s) and phenotype(s) associated with a protein.<p><a href='/help/pathology_and_biotech_section' target='_top'>More...</a></p>Pathology & Biotechi

<p>This subsection of the ‘Pathology and Biotech’ section provides information on the disease(s) associated with genetic variations in a given protein. The information is extracted from the scientific literature and diseases that are also described in the <a href="http://www.ncbi.nlm.nih.gov/sites/entrez?db=omim">OMIM</a> database are represented with a <a href="http://www.uniprot.org/diseases">controlled vocabulary</a> in the following way:<p><a href='/help/involvement_in_disease' target='_top'>More...</a></p>Involvement in diseasei

Niemann-Pick disease A (NPDA)18 Publications
The disease is caused by mutations affecting the gene represented in this entry.
Disease descriptionAn early-onset lysosomal storage disorder caused by failure to hydrolyze sphingomyelin to ceramide. It results in the accumulation of sphingomyelin and other metabolically related lipids in reticuloendothelial and other cell types throughout the body, leading to cell death. Niemann-Pick disease type A is a primarily neurodegenerative disorder characterized by onset within the first year of life, mental retardation, digestive disorders, failure to thrive, major hepatosplenomegaly, and severe neurologic symptoms. The severe neurological disorders and pulmonary infections lead to an early death, often around the age of four. Clinical features are variable. A phenotypic continuum exists between type A (basic neurovisceral) and type B (purely visceral) forms of Niemann-Pick disease, and the intermediate types encompass a cluster of variants combining clinical features of both types A and B.
See also OMIM:257200
Feature keyPosition(s)DescriptionActionsGraphical viewLength
<p>This subsection of the ‘Sequence’ section describes natural variant(s) of the protein sequence.<p><a href='/help/variant' target='_top'>More...</a></p>Natural variantiVAR_060877186P → L in NPDA; reduces enzyme activity; intermediate form with clinical features of both Niemann-Pick disease types A and B. 1 Publication1
Natural variantiVAR_068435211W → R in NPDA; results in less than 0.5% of wild-type activity. 1 Publication1
Natural variantiVAR_077311216L → R in NPDA. 1 Publication1
Natural variantiVAR_075324228C → R in NPDA. 1 Publication1
Natural variantiVAR_060883230R → H in NPDA; intermediate form with clinical features of both Niemann-Pick disease types A and B. 1 Publication1
Natural variantiVAR_060885243A → V in NPDA; intermediate form with clinical features of both Niemann-Pick disease types A and B. 1 Publication1
Natural variantiVAR_075325247G → D in NPDA; severe decrease in activity; the mutant is highly unstable. 1 Publication1
Natural variantiVAR_060888248E → K in NPDA. 1 Publication1
Natural variantiVAR_060889253D → E in NPDA; strongly reduces enzyme activity; intermediate form with clinical features of both Niemann-Pick disease types A and B. 1 Publication1
Natural variantiVAR_068436253D → H in NPDA; results in loss of activity. 1 Publication1
Natural variantiVAR_077312255P → S in NPDA. 1 Publication1
Natural variantiVAR_060890280D → A in NPDA; strongly reduces enzyme activity; intermediate form with clinical features of both Niemann-Pick disease types A and B. 1 Publication1
Natural variantiVAR_060893294Q → K in NPDA; strongly reduces enzyme activity; intermediate form with clinical features of both Niemann-Pick disease types A and B. 3 Publications1
Natural variantiVAR_005060304L → P in NPDA; in 23% of NPDA Ashkenazi Jewish patients; abolishes enzyme activity. 2 Publications1
Natural variantiVAR_060895315Y → H in NPDA. 1 Publication1
Natural variantiVAR_077314319G → R in NPDA. 1 Publication1
Natural variantiVAR_015288321H → Y in NPDA. 2 Publications1
Natural variantiVAR_077316324T → P in NPDA; unknown pathological significance. 1 Publication1
Natural variantiVAR_060898343L → P in NPDA; strongly reduces enzyme activity; intermediate form with clinical features of both Niemann-Pick disease types A and B. 2 Publications1
Natural variantiVAR_077317343L → R in NPDA. 1 Publication1
Natural variantiVAR_077318363L → R in NPDA; unknown pathological significance. 1 Publication1
Natural variantiVAR_060900369Y → C in NPDA. 2 Publications1
Natural variantiVAR_075327387C → R in NPDA. 1 Publication1
Natural variantiVAR_077319391N → H in NPDA. 1 Publication1
Natural variantiVAR_005063391N → T in NPDA. 1 Publication1
Natural variantiVAR_060904392Missing in NPDA. 1 Publication1
Natural variantiVAR_077320393W → R in NPDA; intermediate form. 1 Publication1
Natural variantiVAR_060906423H → R in NPDA. 1 Publication1
Natural variantiVAR_077321426G → S in NPDA. 1 Publication1
Natural variantiVAR_011388448Y → C in NPDA. 1 Publication1
Natural variantiVAR_060910452L → P in NPDA. 1 Publication1
Natural variantiVAR_015291465F → S in NPDA. 2 Publications1
Natural variantiVAR_060913469Y → S in NPDA. 1 Publication1
Natural variantiVAR_075329482Missing in NPDA; unknown pathological significance. 1 Publication1
Natural variantiVAR_060916484A → E in NPDA. 1 Publication1
Natural variantiVAR_077322494N → I in NPDA; intermediate form. 1 Publication1
Natural variantiVAR_060922498R → H in NPDA. 2 Publications1
Natural variantiVAR_005066498R → L in NPDA; in 32% of NPDA Ashkenazi Jewish patients; nearly abolishes enzyme activity. 3 Publications1
Natural variantiVAR_060926519Y → C in NPDA. 1 Publication1
Natural variantiVAR_015293539Y → H in NPDA. 2 Publications1
Natural variantiVAR_075331572F → L in NPDA; results in decreased activity; decreased stability. 1 Publication1
Natural variantiVAR_005067579G → S in NPDA; impairs enzyme activity; also in patients with an intermediate form. 2 Publications1
Natural variantiVAR_060931594Missing in NPDA. 1 Publication1
Niemann-Pick disease B (NPDB)24 Publications
The disease is caused by mutations affecting the gene represented in this entry.
Disease descriptionA late-onset lysosomal storage disorder caused by failure to hydrolyze sphingomyelin to ceramide. It results in the accumulation of sphingomyelin and other metabolically related lipids in reticuloendothelial and other cell types throughout the body, leading to cell death. Clinical signs involve only visceral organs. The most constant sign is hepatosplenomegaly which can be associated with pulmonary symptoms. Patients remain free of neurologic manifestations. However, a phenotypic continuum exists between type A (basic neurovisceral) and type B (purely visceral) forms of Niemann-Pick disease, and the intermediate types encompass a cluster of variants combining clinical features of both types A and B. In Niemann-Pick disease type B, onset of the first symptoms occurs in early childhood and patients can survive into adulthood.
See also OMIM:607616
Feature keyPosition(s)DescriptionActionsGraphical viewLength
Natural variantiVAR_06087051D → V in NPDB; unknown pathological significance. 1 Publication1
Natural variantiVAR_07532291C → H in NPDB; requires 2 nucleotide substitutions. 1 Publication1
Natural variantiVAR_06087194C → W in NPDB. 1 Publication1
Natural variantiVAR_060873132V → A in NPDB; expresses protein level comparable to wild-type SMPD1 expressing cells; retains 13% residual enzyme activity. 1 Publication1
Natural variantiVAR_060874139L → P in NPDB. 1 Publication1
Natural variantiVAR_011387159C → R in NPDB. 2 Publications1
Natural variantiVAR_075323163L → P in NPDB. 1 Publication1
Natural variantiVAR_060875168G → R in NPDB; also in patients with an intermediate form. 2 Publications1
Natural variantiVAR_060876178I → N in NPDB. 1 Publication1
Natural variantiVAR_060878198A → P in NPDB. 1 Publication1
Natural variantiVAR_060879202R → C in NPDB. 1 Publication1
Natural variantiVAR_060880227L → M in NPDB. 1 Publication1
Natural variantiVAR_060881227L → P in NPDB; expresses protein level comparable to wild-type SMPD1 expressing cells; retains no enzyme activity. 2 Publications1
Natural variantiVAR_060884234G → D in NPDB. 1 Publication1
Natural variantiVAR_005058244G → R in NPDB. 1 Publication1
Natural variantiVAR_060886246W → C in NPDB; expresses protein level comparable to wild-type SMPD1 expressing cells; retains no enzyme activity. 2 Publications1
Natural variantiVAR_005059248E → Q in NPDB; 30% residual activity. 1 Publication1
Natural variantiVAR_075326258T → I in NPDB. 1 Publication1
Natural variantiVAR_077313282P → F in NPDB; requires 2 nucleotide substitutions. 1 Publication1
Natural variantiVAR_060891283A → T in NPDB; expresses protein level comparable to wild-type SMPD1 expressing cells; retains no enzyme activity. 2 Publications1
Natural variantiVAR_060892291R → H in NPDB; also in patients with an intermediate form; unknown pathological significance. 2 Publications1
Natural variantiVAR_068437314V → M in NPDB; results in 20% of wild-type activity. 1 Publication1
Natural variantiVAR_077315320N → D in NPDB; unknown pathological significance. 1 Publication1
Natural variantiVAR_060896325P → A in NPDB; results in 1-4% of wild type activity. 3 Publications1
Natural variantiVAR_060897332P → R in NPDB. 2 Publications1
Natural variantiVAR_060899359A → D in NPDB; sphingomyelinase activity is decreased to 4% of wild-type activity; no effect on protein abundance; no effect on protein localization to lysosome; no effect on protein localization to extracellular space. 3 Publications1
Natural variantiVAR_015289373P → S in NPDB. 2 Publications1
Natural variantiVAR_060901378R → H in NPDB; reduces enzyme activity; some patients have a NPDA/NPDB intermediate phenotype. 4 Publications1
Natural variantiVAR_060902378R → L in NPDB. 1 Publication1
Natural variantiVAR_060903381S → P in NPDB. 1 Publication1
Natural variantiVAR_005062385N → S in NPDB. 1 Publication1
Natural variantiVAR_005064393W → G in NPDB; low sphingomyelin degradation rates. 1 Publication1
Natural variantiVAR_060905415A → V in NPDB. 1 Publication1
Natural variantiVAR_015290423H → Y in NPDB; abolishes enzyme activity. 2 Publications1
Natural variantiVAR_068438427H → R in NPDB; results in loss of activity; the patient also carries mutation H-228 that has sufficient activity to account for the Niemann-Pick disease type B phenotype. 1 Publication1
Natural variantiVAR_060907433C → R in NPDB. 1 Publication1
Natural variantiVAR_060908434L → P in NPDB. 1 Publication1
Natural variantiVAR_060909437W → C in NPDB. 1 Publication1
Natural variantiVAR_005065438S → R in NPDB. 1 Publication1
Natural variantiVAR_068439453A → D in NPDB. 1 Publication1
Natural variantiVAR_060911454A → V in NPDB. 1 Publication1
Natural variantiVAR_060912458G → D in NPDB. 1 Publication1
Natural variantiVAR_075328476R → Q in NPDB; unknown pathological significance. 1 Publication1
Natural variantiVAR_060914476R → W in NPDB; some patients have a NPDA/NPDB intermediate phenotype. 4 Publications1
Natural variantiVAR_060915482F → L in NPDB. 1 Publication1
Natural variantiVAR_060918488T → A in NPDB. 1 Publication1
Natural variantiVAR_060919490Y → N in NPDB. 1 Publication1
Natural variantiVAR_075330492G → S in NPDB. 1 Publication1
Natural variantiVAR_060920496G → S in NPDB. 1 Publication1
Natural variantiVAR_060921498R → C in NPDB. 1 Publication1
Natural variantiVAR_060924516H → Q in NPDB. 1 Publication1
Natural variantiVAR_060925517E → V in NPDB. 1 Publication1
Natural variantiVAR_077324520I → L in NPDB. 1 Publication1
Natural variantiVAR_068440522N → S in NPDB. 1 Publication1
Natural variantiVAR_068441525Q → H in NPDB; results in 64% of wild-type activity. 1 Publication1
Natural variantiVAR_077325549N → K in NPDB. 1 Publication1
Natural variantiVAR_060928551L → P in NPDB. 2 Publications1
Natural variantiVAR_060929565D → Y in NPDB; expresses protein level comparable to wild-type SMPD1 expressing cells; retains 6.8% residual enzyme activity. 1 Publication1
Natural variantiVAR_075332577H → D in NPDB; unknown pathological significance. 1 Publication1
Natural variantiVAR_060930578K → N in NPDB. 1 Publication1
Natural variantiVAR_075333598Q → R in NPDB. 1 Publication1
Natural variantiVAR_075334599L → F in NPDB; unknown pathological significance. 1 Publication1
Natural variantiVAR_060933602R → P in NPDB; expresses protein level comparable to wild-type SMPD1 expressing cells; retains very low enzyme activity. 2 Publications1
Natural variantiVAR_075335610R → C in NPDB; unknown pathological significance. 1 Publication1
Natural variantiVAR_005068610Missing in NPDB; nearly abolishes enzyme activity; some patients have a NPDA/NPDB intermediate phenotype. 6 Publications1

Keywords - Diseasei

Disease mutation, Neurodegeneration, Niemann-Pick disease

Organism-specific databases

DisGeNET

More...DisGeNETi		6609

GeneReviews a resource of expert-authored, peer-reviewed disease descriptions.

More...GeneReviewsi		SMPD1

MalaCards human disease database

More...MalaCardsi		SMPD1
MIMi257200 phenotype
607616 phenotype

Open Targets

More...OpenTargetsi		ENSG00000166311

Orphanet; a database dedicated to information on rare diseases and orphan drugs

More...Orphaneti		77292 Niemann-Pick disease type A
77293 Niemann-Pick disease type B

The Pharmacogenetics and Pharmacogenomics Knowledge Base

More...PharmGKBi		PA35969

Chemistry databases

ChEMBL database of bioactive drug-like small molecules

More...ChEMBLi		CHEMBL2760

Drug and drug target database

More...DrugBanki		DB00381 Amlodipine
DB00477 Chlorpromazine
DB01151 Desipramine

Polymorphism and mutation databases

BioMuta curated single-nucleotide variation and disease association database

More...BioMutai		SMPD1

Domain mapping of disease mutations (DMDM)

More...DMDMi		224471897

<p>This section describes post-translational modifications (PTMs) and/or processing events.<p><a href='/help/ptm_processing_section' target='_top'>More...</a></p>PTM / Processingi

Molecule processing

Feature keyPosition(s)DescriptionActionsGraphical viewLength
<p>This subsection of the ‘PTM / Processing’ section denotes the presence of an N-terminal signal peptide.<p><a href='/help/signal' target='_top'>More...</a></p>Signal peptidei1 – 46Add BLAST46
<p>This subsection of the ‘PTM / Processing’ section describes the extent of a polypeptide chain in the mature protein following processing.<p><a href='/help/chain' target='_top'>More...</a></p>ChainiPRO_000000232347 – 631Sphingomyelin phosphodiesteraseAdd BLAST585

Amino acid modifications

Feature keyPosition(s)DescriptionActionsGraphical viewLength
<p>This subsection of the <a href="http://www.uniprot.org/help/ptm_processing_section">PTM / Processing</a> section specifies the position and type of each covalently attached glycan group (mono-, di-, or polysaccharide).<p><a href='/help/carbohyd' target='_top'>More...</a></p>Glycosylationi88N-linked (GlcNAc...) asparaginePROSITE-ProRule annotationCombined sources2 Publications1
<p>This subsection of the PTM / Processing":/help/ptm_processing_section section describes the positions of cysteine residues participating in disulfide bonds.<p><a href='/help/disulfid' target='_top'>More...</a></p>Disulfide bondi91 ↔ 167PROSITE-ProRule annotationCombined sources1 Publication
Disulfide bondi94 ↔ 159PROSITE-ProRule annotationCombined sources1 Publication
Disulfide bondi122 ↔ 133PROSITE-ProRule annotationCombined sources2 Publications
Glycosylationi177N-linked (GlcNAc...) asparaginePROSITE-ProRule annotationCombined sources2 Publications1
Disulfide bondi223 ↔ 228PROSITE-ProRule annotationCombined sources2 Publications
Disulfide bondi229 ↔ 252PROSITE-ProRule annotationCombined sources2 Publications
Glycosylationi337N-linked (GlcNAc...) asparaginePROSITE-ProRule annotationCombined sources2 Publications1
Disulfide bondi387 ↔ 433PROSITE-ProRule annotationCombined sources2 Publications
Glycosylationi397N-linked (GlcNAc...) asparaginePROSITE-ProRule annotationCombined sources2 Publications1
Glycosylationi505N-linked (GlcNAc...) asparagineCombined sources1 Publication1
Glycosylationi522N-linked (GlcNAc...) asparaginePROSITE-ProRule annotationCombined sources2 Publications1
Disulfide bondi586 ↔ 590PROSITE-ProRule annotationCombined sources2 Publications
Disulfide bondi596 ↔ 609PROSITE-ProRule annotationCombined sources2 Publications

Keywords - PTMi

Disulfide bond, Glycoprotein

Proteomic databases

MaxQB - The MaxQuant DataBase

More...MaxQBi		P17405

PaxDb, a database of protein abundance averages across all three domains of life

More...PaxDbi		P17405

PeptideAtlas

More...PeptideAtlasi		P17405

PRoteomics IDEntifications database

More...PRIDEi		P17405

ProteomicsDB human proteome resource

More...ProteomicsDBi		53470
53471 [P17405-2]
53472 [P17405-3]

PTM databases

iPTMnet integrated resource for PTMs in systems biology context

More...iPTMneti		P17405

Comprehensive resource for the study of protein post-translational modifications (PTMs) in human, mouse and rat.

More...PhosphoSitePlusi		P17405

<p>This section provides information on the expression of a gene at the mRNA or protein level in cells or in tissues of multicellular organisms.<p><a href='/help/expression_section' target='_top'>More...</a></p>Expressioni

Gene expression databases

Bgee dataBase for Gene Expression Evolution

More...Bgeei		ENSG00000166311 Expressed in 212 organ(s), highest expression level in right lobe of liver

CleanEx database of gene expression profiles

More...CleanExi		HS_SMPD1

ExpressionAtlas, Differential and Baseline Expression

More...ExpressionAtlasi		P17405 baseline and differential

Genevisible search portal to normalized and curated expression data from Genevestigator

More...Genevisiblei		P17405 HS

<p>This section provides information on the quaternary structure of a protein and on interaction(s) with other proteins or protein complexes.<p><a href='/help/interaction_section' target='_top'>More...</a></p>Interactioni

<p>This subsection of the <a href="http://www.uniprot.org/help/interaction_section">'Interaction'</a> section provides information about the protein quaternary structure and interaction(s) with other proteins or protein complexes (with the exception of physiological receptor-ligand interactions which are annotated in the <a href="http://www.uniprot.org/help/function_section">'Function'</a> section).<p><a href='/help/subunit_structure' target='_top'>More...</a></p>Subunit structurei

Monomer.1 Publication

<p>This subsection of the '<a href="http://www.uniprot.org/help/interaction_section%27">Interaction</a> section provides information about binary protein-protein interactions. The data presented in this section are a quality-filtered subset of binary interactions automatically derived from the <a href="http://www.ebi.ac.uk/intact/">IntAct database</a>. It is updated on a monthly basis. Each binary interaction is displayed on a separate line.<p><a href='/help/binary_interactions' target='_top'>More...</a></p>Binary interactionsi

WithEntry#Exp.IntActNotes
CASP7P552106EBI-7095800,EBI-523958

Protein-protein interaction databases

The Biological General Repository for Interaction Datasets (BioGrid)

More...BioGridi		112493, 14 interactors

Protein interaction database and analysis system

More...IntActi		P17405, 7 interactors

Molecular INTeraction database

More...MINTi		P17405

STRING: functional protein association networks

More...STRINGi		9606.ENSP00000340409

Chemistry databases

BindingDB database of measured binding affinities

More...BindingDBi		P17405

<p>This section provides information on the tertiary and secondary structure of a protein.<p><a href='/help/structure_section' target='_top'>More...</a></p>Structurei

Secondary structure

1631
Legend: HelixTurnBeta strandPDB Structure known for this area
Show more details

3D structure databases

Protein Model Portal of the PSI-Nature Structural Biology Knowledgebase

More...ProteinModelPortali		P17405

SWISS-MODEL Repository - a database of annotated 3D protein structure models

More...SMRi		P17405

Database of comparative protein structure models

More...ModBasei		Search...

MobiDB: a database of protein disorder and mobility annotations

More...MobiDBi		Search...

<p>This section provides information on sequence similarities with other proteins and the domain(s) present in a protein.<p><a href='/help/family_and_domains_section' target='_top'>More...</a></p>Family & Domainsi

Domains and Repeats

Feature keyPosition(s)DescriptionActionsGraphical viewLength
<p>This subsection of the <a href="http://www.uniprot.org/help/family_and_domains_section">Family and Domains</a> section describes the position and type of a domain, which is defined as a specific combination of secondary structures organized into a characteristic three-dimensional structure or fold.<p><a href='/help/domain' target='_top'>More...</a></p>Domaini87 – 171Saposin B-typePROSITE-ProRule annotationAdd BLAST85

<p>This subsection of the ‘Family and domains’ section provides information about the sequence similarity with other proteins.<p><a href='/help/sequence_similarities' target='_top'>More...</a></p>Sequence similaritiesi

Belongs to the acid sphingomyelinase family.Curated

Keywords - Domaini

Signal

Phylogenomic databases

evolutionary genealogy of genes: Non-supervised Orthologous Groups

More...eggNOGi		KOG3770 Eukaryota
ENOG410YYPB LUCA

Ensembl GeneTree

More...GeneTreei		ENSGT00940000156156

The HOVERGEN Database of Homologous Vertebrate Genes

More...HOVERGENi		HBG004288

InParanoid: Eukaryotic Ortholog Groups

More...InParanoidi		P17405

KEGG Orthology (KO)

More...KOi		K12350

Database of Orthologous Groups

More...OrthoDBi		EOG091G03M6

Database for complete collections of gene phylogenies

More...PhylomeDBi		P17405

TreeFam database of animal gene trees

More...TreeFami		TF313674

Family and domain databases

Gene3D Structural and Functional Annotation of Protein Families

More...Gene3Di		3.60.21.10, 1 hit

Integrated resource of protein families, domains and functional sites

More...InterProi		View protein in InterPro
IPR004843 Calcineurin-like_PHP_ApaH
IPR029052 Metallo-depent_PP-like
IPR011001 Saposin-like
IPR008139 SaposinB_dom
IPR011160 Sphingomy_PDE

Pfam protein domain database

More...Pfami		View protein in Pfam
PF00149 Metallophos, 1 hit

PIRSF; a whole-protein classification database

More...PIRSFi		PIRSF000948 Sphingomy_PDE, 1 hit

Simple Modular Architecture Research Tool; a protein domain database

More...SMARTi		View protein in SMART
SM00741 SapB, 1 hit

Superfamily database of structural and functional annotation

More...SUPFAMi		SSF47862 SSF47862, 1 hit

PROSITE; a protein domain and family database

More...PROSITEi		View protein in PROSITE
PS50015 SAP_B, 1 hit

<p>This section displays by default the canonical protein sequence and upon request all isoforms described in the entry. It also includes information pertinent to the sequence(s), including <a href="http://www.uniprot.org/help/sequence_length">length</a> and <a href="http://www.uniprot.org/help/sequences">molecular weight</a>.<p><a href='/help/sequences_section' target='_top'>More...</a></p>Sequences (4+)i

<p>This subsection of the <a href="http://www.uniprot.org/help/sequences_section">Sequence</a> section indicates if the <a href="http://www.uniprot.org/help/canonical_and_isoforms">canonical sequence</a> displayed by default in the entry is complete or not.<p><a href='/help/sequence_status' target='_top'>More...</a></p>Sequence statusi: Complete.

<p>This subsection of the <a href="http://www.uniprot.org/help/sequences_section">Sequence</a> section indicates if the <a href="http://www.uniprot.org/help/canonical_and_isoforms">canonical sequence</a> displayed by default in the entry is in its mature form or if it represents the precursor.<p><a href='/help/sequence_processing' target='_top'>More...</a></p>Sequence processingi: The displayed sequence is further processed into a mature form.

This entry describes 4 <p>This subsection of the ‘Sequence’ section lists the alternative protein sequences (isoforms) that can be generated from the same gene by a single or by the combination of up to four biological events (alternative promoter usage, alternative splicing, alternative initiation and ribosomal frameshifting). Additionally, this section gives relevant information on each alternative protein isoform.<p><a href='/help/alternative_products' target='_top'>More...</a></p> isoformsi produced by alternative splicing. AlignAdd to basket

This entry has 4 described isoforms and 5 potential isoforms that are computationally mapped.Show allAlign All

Isoform 1 (identifier: P17405-1) [UniParc]FASTAAdd to basket
Also known as: ASM-1

This isoform has been chosen as the 'canonical' sequence. All positional information in this entry refers to it. This is also the sequence that appears in the downloadable versions of the entry.

« Hide
        10         20         30         40         50
MPRYGASLRQ SCPRSGREQG QDGTAGAPGL LWMGLVLALA LALALALALS 
        60         70         80         90        100
DSRVLWAPAE AHPLSPQGHP ARLHRIVPRL RDVFGWGNLT CPICKGLFTA 
       110        120        130        140        150
INLGLKKEPN VARVGSVAIK LCNLLKIAPP AVCQSIVHLF EDDMVEVWRR 
       160        170        180        190        200
SVLSPSEACG LLLGSTCGHW DIFSSWNISL PTVPKPPPKP PSPPAPGAPV 
       210        220        230        240        250
SRILFLTDLH WDHDYLEGTD PDCADPLCCR RGSGLPPASR PGAGYWGEYS 
       260        270        280        290        300
KCDLPLRTLE SLLSGLGPAG PFDMVYWTGD IPAHDVWHQT RQDQLRALTT 
       310        320        330        340        350
VTALVRKFLG PVPVYPAVGN HESTPVNSFP PPFIEGNHSS RWLYEAMAKA 
       360        370        380        390        400
WEPWLPAEAL RTLRIGGFYA LSPYPGLRLI SLNMNFCSRE NFWLLINSTD 
       410        420        430        440        450
PAGQLQWLVG ELQAAEDRGD KVHIIGHIPP GHCLKSWSWN YYRIVARYEN 
       460        470        480        490        500
TLAAQFFGHT HVDEFEVFYD EETLSRPLAV AFLAPSATTY IGLNPGYRVY 
       510        520        530        540        550
QIDGNYSGSS HVVLDHETYI LNLTQANIPG AIPHWQLLYR ARETYGLPNT 
       560        570        580        590        600
LPTAWHNLVY RMRGDMQLFQ TFWFLYHKGH PPSEPCGTPC RLATLCAQLS 
       610        620        630 
ARADSPALCR HLMPDGSLPE AQSLWPRPLF C
Note: Most abundant (90%).
Length:631
Mass (Da):69,936
Last modified:September 12, 2018 - v5
<p>The checksum is a form of redundancy check that is calculated from the sequence. It is useful for tracking sequence updates.</p> <p>It should be noted that while, in theory, two different sequences could have the same checksum value, the likelihood that this would happen is extremely low.</p> <p>However UniProtKB may contain entries with identical sequences in case of multiple genes (paralogs).</p> <p>The checksum is computed as the sequence 64-bit Cyclic Redundancy Check value (CRC64) using the generator polynomial: x<sup>64</sup> + x<sup>4</sup> + x<sup>3</sup> + x + 1. The algorithm is described in the ISO 3309 standard. </p> <p class="publication">Press W.H., Flannery B.P., Teukolsky S.A. and Vetterling W.T.<br /> <strong>Cyclic redundancy and other checksums</strong><br /> <a href="http://www.nrbook.com/b/bookcpdf.php">Numerical recipes in C 2nd ed., pp896-902, Cambridge University Press (1993)</a>)</p> Checksum:iF229709F6A9B0E9E
GO
Isoform 2 (identifier: P17405-2) [UniParc]FASTAAdd to basket
Also known as: ASM-2

The sequence of this isoform differs from the canonical sequence as follows:
     365-376: IGGFYALSPYPG → YLSSVETQEGKR
     377-420: Missing.

Note: Intermediate abundance (10%).
Show »
Length:587
Mass (Da):65,074
Checksum:i6CC3B78ECC26F486
GO
Isoform 3 (identifier: P17405-3) [UniParc]FASTAAdd to basket
Also known as: ASM-3

The sequence of this isoform differs from the canonical sequence as follows:
     365-420: Missing.

Note: Low abundance (<1%).
Show »
Length:575
Mass (Da):63,695
Checksum:i1C5A1828208B388D
GO
Isoform 4 (identifier: P17405-4) [UniParc]FASTAAdd to basket

The sequence of this isoform differs from the canonical sequence as follows:
     106-106: Missing.

Show »
Length:630
Mass (Da):69,808
Checksum:i14F8DDFDAB36229A
GO

<p>In eukaryotic reference proteomes, unreviewed entries that are likely to belong to the same gene are computationally mapped, based on gene identifiers from Ensembl, EnsemblGenomes and model organism databases.<p><a href='/help/gene_centric_isoform_mapping' target='_top'>More...</a></p>Computationally mapped potential isoform sequencesi

There are 5 potential isoforms mapped to this entry.BLASTAlignShow allAdd to basket
EntryEntry nameProtein names
Gene namesLengthAnnotation
E9PQT3E9PQT3_HUMAN
Sphingomyelin phosphodiesterase
SMPD1
402Annotation score:

Annotation score:1 out of 5

<p>The annotation score provides a heuristic measure of the annotation content of a UniProtKB entry or proteome. This score <strong>cannot</strong> be used as a measure of the accuracy of the annotation as we cannot define the ‘correct annotation’ for any given protein.<p><a href='/help/annotation_score' target='_top'>More...</a></p>
G3V1E1G3V1E1_HUMAN
Sphingomyelin phosphodiesterase
SMPD1 hCG_24080
366Annotation score:

Annotation score:1 out of 5

<p>The annotation score provides a heuristic measure of the annotation content of a UniProtKB entry or proteome. This score <strong>cannot</strong> be used as a measure of the accuracy of the annotation as we cannot define the ‘correct annotation’ for any given protein.<p><a href='/help/annotation_score' target='_top'>More...</a></p>
E9PPK6E9PPK6_HUMAN
Sphingomyelin phosphodiesterase
SMPD1
171Annotation score:

Annotation score:1 out of 5

<p>The annotation score provides a heuristic measure of the annotation content of a UniProtKB entry or proteome. This score <strong>cannot</strong> be used as a measure of the accuracy of the annotation as we cannot define the ‘correct annotation’ for any given protein.<p><a href='/help/annotation_score' target='_top'>More...</a></p>
H0YEP5H0YEP5_HUMAN
Sphingomyelin phosphodiesterase
SMPD1
317Annotation score:

Annotation score:1 out of 5

<p>The annotation score provides a heuristic measure of the annotation content of a UniProtKB entry or proteome. This score <strong>cannot</strong> be used as a measure of the accuracy of the annotation as we cannot define the ‘correct annotation’ for any given protein.<p><a href='/help/annotation_score' target='_top'>More...</a></p>
E9PL59E9PL59_HUMAN
Sphingomyelin phosphodiesterase
SMPD1
52Annotation score:

Annotation score:1 out of 5

<p>The annotation score provides a heuristic measure of the annotation content of a UniProtKB entry or proteome. This score <strong>cannot</strong> be used as a measure of the accuracy of the annotation as we cannot define the ‘correct annotation’ for any given protein.<p><a href='/help/annotation_score' target='_top'>More...</a></p>

Experimental Info

Feature keyPosition(s)DescriptionActionsGraphical viewLength
<p>This subsection of the ‘Sequence’ section reports difference(s) between the canonical sequence (displayed by default in the entry) and the different sequence submissions merged in the entry. These various submissions may originate from different sequencing projects, different types of experiments, or different biological samples. Sequence conflicts are usually of unknown origin.<p><a href='/help/conflict' target='_top'>More...</a></p>Sequence conflicti270G → D in BAF85077 (PubMed:14702039).Curated1

<p>This subsection of the ‘Sequence’ section provides information on polymorphic variants. If the variant is associated with a disease state, the description of the latter can be found in the <a href="http://www.uniprot.org/manual/involvement_in_disease">'Involvement in disease'</a> subsection.<p><a href='/help/polymorphism' target='_top'>More...</a></p>Polymorphismi

A common polymorphism arises from a variable number of hexanucleotide repeat sequence within the signal peptide region.

Natural variant

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Natural variantiVAR_08064136 – 39Missing 2 PublicationsCorresponds to variant dbSNP:rs550365194Ensembl.4
Natural variantiVAR_03819136V → A Polymorphism; does not affect enzymatic activity. 3 PublicationsCorresponds to variant dbSNP:rs1050228EnsemblClinVar.1
Natural variantiVAR_08064248 – 49Missing 4 PublicationsCorresponds to variant dbSNP:rs3838786Ensembl.2
Natural variantiVAR_06087051D → V in NPDB; unknown pathological significance. 1 Publication1
Natural variantiVAR_07532291C → H in NPDB; requires 2 nucleotide substitutions. 1 Publication1
Natural variantiVAR_06087194C → W in NPDB. 1 Publication1
Natural variantiVAR_060872105L → P in NPDA and NPDB; expresses protein level comparable to wild-type SMPD1 expressing cells; retains very low enzyme activity. 5 Publications1
Natural variantiVAR_060873132V → A in NPDB; expresses protein level comparable to wild-type SMPD1 expressing cells; retains 13% residual enzyme activity. 1 Publication1
Natural variantiVAR_060874139L → P in NPDB. 1 Publication1
Natural variantiVAR_011387159C → R in NPDB. 2 Publications1
Natural variantiVAR_075323163L → P in NPDB. 1 Publication1
Natural variantiVAR_060875168G → R in NPDB; also in patients with an intermediate form. 2 Publications1
Natural variantiVAR_060876178I → N in NPDB. 1 Publication1
Natural variantiVAR_060877186P → L in NPDA; reduces enzyme activity; intermediate form with clinical features of both Niemann-Pick disease types A and B. 1 Publication1
Natural variantiVAR_060878198A → P in NPDB. 1 Publication1
Natural variantiVAR_060879202R → C in NPDB. 1 Publication1
Natural variantiVAR_068435211W → R in NPDA; results in less than 0.5% of wild-type activity. 1 Publication1
Natural variantiVAR_077311216L → R in NPDA. 1 Publication1
Natural variantiVAR_060880227L → M in NPDB. 1 Publication1
Natural variantiVAR_060881227L → P in NPDB; expresses protein level comparable to wild-type SMPD1 expressing cells; retains no enzyme activity. 2 Publications1
Natural variantiVAR_075324228C → R in NPDA. 1 Publication1
Natural variantiVAR_060882230R → C in NPDB and NPDA; some patients have a NPDA/NPDB intermediate phenotype. 5 Publications1
Natural variantiVAR_060883230R → H in NPDA; intermediate form with clinical features of both Niemann-Pick disease types A and B. 1 Publication1
Natural variantiVAR_060884234G → D in NPDB. 1 Publication1
Natural variantiVAR_060885243A → V in NPDA; intermediate form with clinical features of both Niemann-Pick disease types A and B. 1 Publication1
Natural variantiVAR_005058244G → R in NPDB. 1 Publication1
Natural variantiVAR_060886246W → C in NPDB; expresses protein level comparable to wild-type SMPD1 expressing cells; retains no enzyme activity. 2 Publications1
Natural variantiVAR_075325247G → D in NPDA; severe decrease in activity; the mutant is highly unstable. 1 Publication1
Natural variantiVAR_060887247G → S in NPDA and NPDB. 4 Publications1
Natural variantiVAR_060888248E → K in NPDA. 1 Publication1
Natural variantiVAR_005059248E → Q in NPDB; 30% residual activity. 1 Publication1
Natural variantiVAR_015287250S → R in NPDA and NPDB; also found in patients with an intermediate form. 4 Publications1
Natural variantiVAR_060889253D → E in NPDA; strongly reduces enzyme activity; intermediate form with clinical features of both Niemann-Pick disease types A and B. 1 Publication1
Natural variantiVAR_068436253D → H in NPDA; results in loss of activity. 1 Publication1
Natural variantiVAR_077312255P → S in NPDA. 1 Publication1
Natural variantiVAR_075326258T → I in NPDB. 1 Publication1
Natural variantiVAR_060890280D → A in NPDA; strongly reduces enzyme activity; intermediate form with clinical features of both Niemann-Pick disease types A and B. 1 Publication1
Natural variantiVAR_077313282P → F in NPDB; requires 2 nucleotide substitutions. 1 Publication1
Natural variantiVAR_060891283A → T in NPDB; expresses protein level comparable to wild-type SMPD1 expressing cells; retains no enzyme activity. 2 Publications