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Protein

Mucolipin-1

Gene

MCOLN1

Organism
Homo sapiens (Human)
Status
Reviewed-Annotation score: Annotation score: 5 out of 5-Experimental evidence at protein leveli

Functioni

Nonselective cation channel probably playing a role in the regulation of membrane trafficking events and of metal homeostasis. Proposed to play a major role in Ca2+ release from late endosome and lysosome vesicles to the cytoplasm, which is important for many lysosome-dependent cellular events, including the fusion and trafficking of these organelles, exocytosis and autophagy (PubMed:11013137, PubMed:12459486, PubMed:15336987, PubMed:14749347). Required for efficient uptake of large particles in macrophages in which Ca2+ release from the lysosomes triggers lysosomal exocytosis. May also play a role in phagosome-lysosome fusion (By similarity). Involved in lactosylceramide trafficking indicative for a role in the regulation of late endocytic membrane fusion/fission events (PubMed:16978393). By mediating lysosomal Ca2+ release is involved in regulation of mTORC1 signaling and in mTOR/TFEB-dependent lysosomal adaptation to environmental cues such as nutrient levels (PubMed:27787197, PubMed:25733853). Seems to act as lysosomal active oxygen species (ROS) sensor involved in ROS-induced TFEB activation and autophagy (PubMed:27357649). Functions as a Fe2+ permeable channel in late endosomes and lysosomes (PubMed:18794901). Proposed to play a role in zinc homeostasis probably implicating its association with TMEM163 (PubMed:25130899) In adaptive immunity, TRPML2 and TRPML1 may play redundant roles in the function of the specialized lysosomes of B cells (By similarity).By similarity1 Publication9 Publications
May contribute to cellular lipase activity within the late endosomal pathway or at the cell surface which may be involved in processes of membrane reshaping and vesiculation, especially the growth of tubular structures. However, it is not known, whether it conveys the enzymatic activity directly, or merely facilitates the activity of an associated phospholipase.1 Publication

Enzyme regulationi

Channel activity is controlled by multiple regulatory mechanisms in different subcellular compartments. Channel function is transiently modulated by changes in Ca2+, and inhibited by a reduction of pH; pH changes modify the aggregation state of unitary channels; a negative cooperativity between extracellular/lumenal Ca2+ and H+ is suggested (PubMed:12459486, PubMed:28112729). Regulated by phosphoinositides in a compartment-specific manner: in lysosomes activated by PtdIns(3,5)P2 (Phosphatidylinositol 3,5-bisphosphate) and at the plasma membrane inhibited by PtdIns(4,5)P2 (Phosphatidylinositol 4,5-bisphosphate) (PubMed:22733759).3 Publications

GO - Molecular functioni

GO - Biological processi

Keywordsi

Molecular functionIon channel
Biological processAdaptive immunity, Calcium transport, Immunity, Ion transport, Transport
LigandCalcium

Enzyme and pathway databases

ReactomeiR-HSA-3295583. TRP channels.
R-HSA-917977. Transferrin endocytosis and recycling.
SIGNORiQ9GZU1.

Protein family/group databases

TCDBi1.A.5.3.1. the polycystin cation channel (pcc) family.

Names & Taxonomyi

Protein namesi
Recommended name:
Mucolipin-1
Short name:
ML1
Alternative name(s):
MG-2
Mucolipidin
Transient receptor potential channel mucolipin 1
Short name:
TRPML1
Gene namesi
Name:MCOLN1
Synonyms:ML4
ORF Names:MSTP080
OrganismiHomo sapiens (Human)
Taxonomic identifieri9606 [NCBI]
Taxonomic lineageiEukaryotaMetazoaChordataCraniataVertebrataEuteleostomiMammaliaEutheriaEuarchontogliresPrimatesHaplorrhiniCatarrhiniHominidaeHomo
Proteomesi
  • UP000005640 Componenti: Chromosome 19

Organism-specific databases

EuPathDBiHostDB:ENSG00000090674.15.
HGNCiHGNC:13356. MCOLN1.

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

Topology

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Topological domaini1 – 65CytoplasmicCuratedAdd BLAST65
Transmembranei66 – 86HelicalSequence analysisAdd BLAST21
Topological domaini87 – 296ExtracellularCuratedAdd BLAST210
Transmembranei297 – 317HelicalSequence analysisAdd BLAST21
Topological domaini318 – 349CytoplasmicCuratedAdd BLAST32
Transmembranei350 – 370HelicalSequence analysisAdd BLAST21
Topological domaini371 – 387ExtracellularCuratedAdd BLAST17
Transmembranei388 – 408HelicalSequence analysisAdd BLAST21
Topological domaini409 – 427CytoplasmicCuratedAdd BLAST19
Transmembranei428 – 448HelicalSequence analysisAdd BLAST21
Topological domaini449 – 496ExtracellularCuratedAdd BLAST48
Transmembranei497 – 517HelicalSequence analysisAdd BLAST21
Topological domaini518 – 580CytoplasmicCuratedAdd BLAST63

Keywords - Cellular componenti

Cell membrane, Cell projection, Cytoplasmic vesicle, Endosome, Lysosome, Membrane

Pathology & Biotechi

Involvement in diseasei

Mucolipidosis 4 (ML4)12 Publications
The disease is caused by mutations affecting the gene represented in this entry.
Disease descriptionAn autosomal recessive lysosomal storage disorder characterized by severe psychomotor retardation and ophthalmologic abnormalities, including corneal opacity, retinal degeneration and strabismus. Storage bodies of lipids and water-soluble substances are seen by electron microscopy in almost every cell type of the patients. Most patients are unable to speak or walk independently and reach a maximal developmental level of 1-2 years. All patients have constitutive achlorhydia associated with a secondary elevation of serum gastrin levels.
See also OMIM:252650
Feature keyPosition(s)DescriptionActionsGraphical viewLength
Natural variantiVAR_019369106L → P in ML4; decreases formation and extrusion of tubulo-vesicular structures when overexpressed; disrupts tetrameric assembly; abolishes lysosomal localization. 3 PublicationsCorresponds to variant dbSNP:rs797044825Ensembl.1
Natural variantiVAR_019370232T → P in ML4; fails to localize to late endosomes; abolishes Fe(2+) permeability; disrupts tetrameric assembly; abolishes lysosomal localization. 4 PublicationsCorresponds to variant dbSNP:rs767122713Ensembl.1
Natural variantiVAR_019371362D → Y in ML4; affects channel activity; abolishes Fe(2+) permeability. 4 PublicationsCorresponds to variant dbSNP:rs121908372Ensembl.1
Natural variantiVAR_038380403R → C in ML4; impairs Fe(2+) permeability. 2 PublicationsCorresponds to variant dbSNP:rs121908374Ensembl.1
Natural variantiVAR_019372408Missing in ML4; mild psychomotor involvement; does not affect channel activity; affects channel inhibition by low pH; still localizes to late endosomes. 5 Publications1
Natural variantiVAR_019373446V → L in ML4; does not affect channel activity; affects channel inhibition by low pH; impairs Fe(2+) permeability. 3 Publications1
Natural variantiVAR_019374447L → P in ML4. 1 PublicationCorresponds to variant dbSNP:rs797044827Ensembl.1
Natural variantiVAR_019375465F → L in ML4; still localizes to late endosomes; fails to rescue defect of lactosylceramide traffic through the late endocytic pathway in ML4 patient cells; minor effect on formation and extrusion of tubulo-vesicular structures when overexpressed. 4 PublicationsCorresponds to variant dbSNP:rs797044828Ensembl.1

Mutagenesis

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Mutagenesisi15 – 16LL → AA: No effect on localization to lysosomes. 1 Publication2
Mutagenesisi15L → A: Abolishes localization to lysosomes; when associated with A-577. 1 Publication1
Mutagenesisi42 – 44RRR → AAA: Reduces PtdIns(4,5)P2 sensitivity. 1 Publication3
Mutagenesisi44 – 46RLK → AAA: Abolishes interaction with PDCD6 and decreases formation of aberrant endosomes upon overexpression. 1 Publication3
Mutagenesisi44R → A: Abolishes interaction with PDCD6. 1 Publication1
Mutagenesisi45L → A: Abolishes interaction with PDCD6. 1 Publication1
Mutagenesisi47 – 49YFF → AAA: Abolishes interaction with PDCD6. 1 Publication3
Mutagenesisi61 – 62RK → AA: Reduces PtdIns(3,5)P2 sensitivity. 1 Publication2
Mutagenesisi109Y → G: Abolishes formation and extrusion of tubulo-vesicular structures and decreases lysosomal exocytosis when overexpressed. 1 Publication1
Mutagenesisi110S → C: Modulates ion conduction; when associoated with C-112 and C-113. 1 Publication1
Mutagenesisi111D → Q: Modulates inhibition by Ca(2+) at different pH levels but does not abolish channel inward rectification; when associated with Q-114 and Q-115. 1 Publication1
Mutagenesisi112G → C: Modulates ion conduction; when associoated with C-110 and C-113. 1 Publication1
Mutagenesisi113A → C: Modulates ion conduction; when associoated with C-110 and C-112. 1 Publication1
Mutagenesisi114D → Q: Modulates inhibition by Ca(2+) at different pH levels but does not abolish channel inward rectification; when associated with Q-111 and Q-115. 1 Publication1
Mutagenesisi115D → Q: Modulates inhibition by Ca(2+) at different pH levels but does not abolish channel inward rectification; when associated with Q-111 and Q-114. 1 Publication1
Mutagenesisi144L → K: Disrupts tetrameric assembly and abolishes lysosomal localization; when associated with S-146. 1 Publication1
Mutagenesisi146R → S: Disrupts tetrameric assembly and abolishes lysosomal localization; when associated with K-144. 1 Publication1
Mutagenesisi200R → H: Does not prevent proteolytic cleavage but changes cleavage pattern. 1 Publication1
Mutagenesisi432V → P: Mediates localization to the plasma membrane and strong inwardly rectifying current. 2 Publications1
Mutagenesisi471D → A: Fails to rescue defect of lactosylceramide traffic through the late endocytic pathway in ML4 patient cells. 1 Publication1
Mutagenesisi565 – 567CCC → AAA: Abolishes association with membranes. 1 Publication3
Mutagenesisi577 – 578LL → AA: No effect on localization to lysosomes. 1 Publication2
Mutagenesisi577L → A: Abolishes localization to lysosomes; when associated with A-15. 1 Publication1

Keywords - Diseasei

Disease mutation, Mucolipidosis

Organism-specific databases

DisGeNETi57192.
GeneReviewsiMCOLN1.
MalaCardsiMCOLN1.
MIMi252650. phenotype.
OpenTargetsiENSG00000090674.
Orphaneti578. Mucolipidosis type 4.
PharmGKBiPA30699.

Chemistry databases

GuidetoPHARMACOLOGYi501.

Polymorphism and mutation databases

BioMutaiMCOLN1.
DMDMi50401163.

PTM / Processingi

Molecule processing

Feature keyPosition(s)DescriptionActionsGraphical viewLength
ChainiPRO_00002153621 – 580Mucolipin-1Add BLAST580

Amino acid modifications

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Modified residuei10PhosphoserineBy similarity1
Disulfide bondi166 ↔ 192Combined sources1 Publication
Glycosylationi230N-linked (GlcNAc...) asparagine1 Publication1
Disulfide bondi253 ↔ 284Combined sources1 Publication
Modified residuei557Phosphoserine; by PAKBy similarity1 Publication1
Modified residuei559Phosphoserine; by PAK1 Publication1

Post-translational modificationi

Palmitoylated; involved in association with membranes.1 Publication
Phosphorylation by PKA inhibits channel activity. Dephosphorylation increases activity.1 Publication
Proteolytically cleaved probably involving multiple lysosomal proteases including cathepsin B; inhibits lysosomal channnel activity (PubMed:16257972).1 Publication

Keywords - PTMi

Disulfide bond, Glycoprotein, Lipoprotein, Palmitate, Phosphoprotein

Proteomic databases

EPDiQ9GZU1.
MaxQBiQ9GZU1.
PaxDbiQ9GZU1.
PeptideAtlasiQ9GZU1.
PRIDEiQ9GZU1.

PTM databases

iPTMnetiQ9GZU1.
PhosphoSitePlusiQ9GZU1.
SwissPalmiQ9GZU1.

Expressioni

Tissue specificityi

Widely expressed in adult and fetal tissues.3 Publications

Gene expression databases

BgeeiENSG00000090674.
CleanExiHS_MCOLN1.
ExpressionAtlasiQ9GZU1. baseline and differential.
GenevisibleiQ9GZU1. HS.

Organism-specific databases

HPAiCAB032637.
HPA031763.

Interactioni

Subunit structurei

Forms homooligomeric complexes; probably tetrameric (PubMed:14749347, PubMed:28112729). Can heterooligomerize with MCOLN2 or MCOLN3; heteromeric assemblies have different channel properties as compared to the respective homooligomers and may be tissue-specific (PubMed:19885840). Interacts with PDCD6 (PubMed:19864416). Interacts with TMEM163 (PubMed:25130899). Interacts with LAPTM4B (PubMed:21224396).1 Publication5 Publications

Binary interactionsi

WithEntry#Exp.IntActNotes
SEC22AQ96IW74EBI-721209,EBI-8652744

Protein-protein interaction databases

BioGridi121441. 9 interactors.
DIPiDIP-62090N.
ELMiQ9GZU1.
IntActiQ9GZU1. 4 interactors.
MINTiMINT-1409368.
STRINGi9606.ENSP00000264079.

Structurei

Secondary structure

1580
Legend: HelixTurnBeta strandPDB Structure known for this area
Show more details
Feature keyPosition(s)DescriptionActionsGraphical viewLength
Helixi84 – 105Combined sources22
Turni114 – 116Combined sources3
Helixi122 – 137Combined sources16
Helixi139 – 142Combined sources4
Beta strandi148 – 151Combined sources4
Beta strandi154 – 156Combined sources3
Beta strandi162 – 176Combined sources15
Helixi177 – 179Combined sources3
Beta strandi181 – 195Combined sources15
Helixi225 – 227Combined sources3
Beta strandi228 – 241Combined sources14
Helixi242 – 247Combined sources6
Beta strandi252 – 263Combined sources12
Beta strandi271 – 282Combined sources12

3D structure databases

Select the link destinations:
PDBei
RCSB PDBi
PDBji
Links Updated
PDB entryMethodResolution (Å)ChainPositionsPDBsum
5TJAX-ray2.30A84-296[»]
5TJBX-ray2.40A84-296[»]
5TJCX-ray2.40A84-296[»]
ProteinModelPortaliQ9GZU1.
SMRiQ9GZU1.
ModBaseiSearch...
MobiDBiSearch...

Family & Domainsi

Region

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Regioni42 – 62Interaction with phosphoinositides1 PublicationAdd BLAST21
Regioni107 – 121Extracellular/lumenal pore loop1 PublicationAdd BLAST15
Regioni565 – 567Required for palmitoylation and association with membranes1 Publication3

Motif

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Motifi11 – 16Dileucine motif; mediates targeting to lysosomes1 Publication6
Motifi573 – 578Dileucine internalization motif; mediates AP2 complex-dependent internalization1 Publication6

Domaini

The most N-terminal extracellular/lumenal domain (referred to as I-II linker or polycystin-mucolipin domain) contributes to a structure with a four-fold rotational symmetry in a tetrameric assembly; the structure contains a central highly electronegative pore with a 14 A diameter. The pore is critical for Ca2+ and pH regulation. The protruding structure formed by the I-II linkers may contain all the interaction sites with lipids and proteins in the endolysosomal lumen.1 Publication

Sequence similaritiesi

Keywords - Domaini

Transmembrane, Transmembrane helix

Phylogenomic databases

eggNOGiKOG3733. Eukaryota.
ENOG410Z1HH. LUCA.
GeneTreeiENSGT00390000017126.
HOGENOMiHOG000232158.
HOVERGENiHBG052430.
InParanoidiQ9GZU1.
KOiK04992.
OMAiPANDTFN.
OrthoDBiEOG091G026A.
PhylomeDBiQ9GZU1.
TreeFamiTF317783.

Family and domain databases

InterProiView protein in InterPro
IPR013122. PKD1_2_channel.
PfamiView protein in Pfam
PF08016. PKD_channel. 1 hit.

Sequencei

Sequence statusi: Complete.

Q9GZU1-1 [UniParc]FASTAAdd to basket

« Hide

        10         20         30         40         50
MTAPAGPRGS ETERLLTPNP GYGTQAGPSP APPTPPEEED LRRRLKYFFM
60 70 80 90 100
SPCDKFRAKG RKPCKLMLQV VKILVVTVQL ILFGLSNQLA VTFREENTIA
110 120 130 140 150
FRHLFLLGYS DGADDTFAAY TREQLYQAIF HAVDQYLALP DVSLGRYAYV
160 170 180 190 200
RGGGDPWTNG SGLALCQRYY HRGHVDPAND TFDIDPMVVT DCIQVDPPER
210 220 230 240 250
PPPPPSDDLT LLESSSSYKN LTLKFHKLVN VTIHFRLKTI NLQSLINNEI
260 270 280 290 300
PDCYTFSVLI TFDNKAHSGR IPISLETQAH IQECKHPSVF QHGDNSFRLL
310 320 330 340 350
FDVVVILTCS LSFLLCARSL LRGFLLQNEF VGFMWRQRGR VISLWERLEF
360 370 380 390 400
VNGWYILLVT SDVLTISGTI MKIGIEAKNL ASYDVCSILL GTSTLLVWVG
410 420 430 440 450
VIRYLTFFHN YNILIATLRV ALPSVMRFCC CVAVIYLGYC FCGWIVLGPY
460 470 480 490 500
HVKFRSLSMV SECLFSLING DDMFVTFAAM QAQQGRSSLV WLFSQLYLYS
510 520 530 540 550
FISLFIYMVL SLFIALITGA YDTIKHPGGA GAEESELQAY IAQCQDSPTS
560 570 580
GKFRRGSGSA CSLLCCCGRD PSEEHSLLVN
Length:580
Mass (Da):65,022
Last modified:March 1, 2001 - v1
Checksum:i7E7691F58D01C804
GO

Sequence cautioni

The sequence AAQ13604 differs from that shown. Reason: Erroneous initiation. Translation N-terminally extended.Curated
The sequence CAC07813 differs from that shown. Probable cloning artifact.Curated
The sequence EAW69031 differs from that shown. Reason: Erroneous gene model prediction.Curated
The sequence EAW69034 differs from that shown. Reason: Erroneous gene model prediction.Curated

Experimental Info

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Sequence conflicti164 – 191ALCQR…MVVTD → LSASGTTTEATWTRPTTHLT LIRWWLLVN in AAG42242 (PubMed:10973263).CuratedAdd BLAST28
Sequence conflicti203P → S in CAC08215 (PubMed:11013137).Curated1

Natural variant

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Natural variantiVAR_019369106L → P in ML4; decreases formation and extrusion of tubulo-vesicular structures when overexpressed; disrupts tetrameric assembly; abolishes lysosomal localization. 3 PublicationsCorresponds to variant dbSNP:rs797044825Ensembl.1
Natural variantiVAR_019370232T → P in ML4; fails to localize to late endosomes; abolishes Fe(2+) permeability; disrupts tetrameric assembly; abolishes lysosomal localization. 4 PublicationsCorresponds to variant dbSNP:rs767122713Ensembl.1
Natural variantiVAR_036453331V → L in a breast cancer sample; somatic mutation. 1 Publication1
Natural variantiVAR_019371362D → Y in ML4; affects channel activity; abolishes Fe(2+) permeability. 4 PublicationsCorresponds to variant dbSNP:rs121908372Ensembl.1
Natural variantiVAR_038380403R → C in ML4; impairs Fe(2+) permeability. 2 PublicationsCorresponds to variant dbSNP:rs121908374Ensembl.1
Natural variantiVAR_019372408Missing in ML4; mild psychomotor involvement; does not affect channel activity; affects channel inhibition by low pH; still localizes to late endosomes. 5 Publications1
Natural variantiVAR_019373446V → L in ML4; does not affect channel activity; affects channel inhibition by low pH; impairs Fe(2+) permeability. 3 Publications1
Natural variantiVAR_019374447L → P in ML4. 1 PublicationCorresponds to variant dbSNP:rs797044827Ensembl.1
Natural variantiVAR_019375465F → L in ML4; still localizes to late endosomes; fails to rescue defect of lactosylceramide traffic through the late endocytic pathway in ML4 patient cells; minor effect on formation and extrusion of tubulo-vesicular structures when overexpressed. 4 PublicationsCorresponds to variant dbSNP:rs797044828Ensembl.1

Sequence databases

Select the link destinations:
EMBLi
GenBanki
DDBJi
Links Updated
AJ293659 mRNA. Translation: CAC07813.1. Sequence problems.
AJ293970 mRNA. Translation: CAC08215.1.
AF287269 mRNA. Translation: AAG00797.1.
AF287270 Genomic DNA. Translation: AAG00798.1.
AF249319 mRNA. Translation: AAG10422.1.
AF305579
, AF305572, AF305573, AF305574, AF305575, AF305576, AF305577, AF305578 Genomic DNA. Translation: AAG42242.1.
AK026102 mRNA. Translation: BAB15360.1.
CH471139 Genomic DNA. Translation: EAW69031.1. Sequence problems.
CH471139 Genomic DNA. Translation: EAW69034.1. Sequence problems.
BC005149 mRNA. Translation: AAH05149.1.
AF171088 mRNA. Translation: AAQ13604.1. Different initiation.
CCDSiCCDS12180.1.
RefSeqiNP_065394.1. NM_020533.2.
UniGeneiHs.631858.

Genome annotation databases

EnsembliENST00000264079; ENSP00000264079; ENSG00000090674.
GeneIDi57192.
KEGGihsa:57192.
UCSCiuc002mgo.4. human.

Keywords - Coding sequence diversityi

Polymorphism

Similar proteinsi

Entry informationi

Entry nameiMCLN1_HUMAN
AccessioniPrimary (citable) accession number: Q9GZU1
Secondary accession number(s): D6W647
, Q7Z4F7, Q9H292, Q9H4B3, Q9H4B5
Entry historyiIntegrated into UniProtKB/Swiss-Prot: July 19, 2004
Last sequence update: March 1, 2001
Last modified: November 22, 2017
This is version 153 of the entry and version 1 of the sequence. See complete history.
Entry statusiReviewed (UniProtKB/Swiss-Prot)
Annotation programChordata Protein Annotation Program
DisclaimerAny medical or genetic information present in this entry is provided for research, educational and informational purposes only. It is not in any way intended to be used as a substitute for professional medical advice, diagnosis, treatment or care.

Miscellaneousi

Caution

There are conflicting results relative to ion selectivity and permeation. Initially outward rectification has been reported which makes the proposed activity as lysosymal Ca2+ release channel unlikely. Inward rectification has been decribed in later studies supporting the Ca2+ release activity.Curated

Keywords - Technical termi

3D-structure, Complete proteome, Reference proteome

Documents

  1. Human chromosome 19
    Human chromosome 19: entries, gene names and cross-references to MIM
  2. Human entries with polymorphisms or disease mutations
    List of human entries with polymorphisms or disease mutations
  3. Human polymorphisms and disease mutations
    Index of human polymorphisms and disease mutations
  4. MIM cross-references
    Online Mendelian Inheritance in Man (MIM) cross-references in UniProtKB/Swiss-Prot
  5. PDB cross-references
    Index of Protein Data Bank (PDB) cross-references
  6. SIMILARITY comments
    Index of protein domains and families