O95445 (APOM_HUMAN) Reviewed, UniProtKB/Swiss-Prot

Names and origin

Protein names

Recommended name:
Apolipoprotein M
Short name=Apo-M
Short name=ApoM

Alternative name(s):
Protein G3a

Gene names

Name:	APOM
Synonyms:	G3A, NG20
ORF Names:	HSPC336

Organism

Homo sapiens (Human)

Taxonomic identifier

9606 [NCBI]

Taxonomic lineage

Eukaryota › Metazoa › Chordata › Craniata › Vertebrata › Euteleostomi › Mammalia › Eutheria › Euarchontoglires › Primates › Haplorrhini › Catarrhini › Hominidae › Homo

Protein attributes

Sequence length	188 AA.
Sequence status	Complete.
Protein existence	Evidence at protein level

General annotation (Comments)

Function	Probably involved in lipid transport. Can bind sphingosine-1-phosphate, myristic acid, palmitic acid and stearic acid, retinol, all-trans-retinoic acid and 9-cis-retinoic acid. Ref.10 Ref.15
Subcellular location	Secreted. Note: Present in high density lipoprotein (HDL) and to a lesser extent in triglyceride-rich lipoproteins (TGRLP) and low density lipoproteins (LDL). Ref.10 Ref.11 Ref.12
Tissue specificity	Plasma protein. Expressed in liver and kidney.
Sequence similarities	Belongs to the calycin superfamily. Lipocalin family. Highly divergent.

Ontologies

Keywords
Biological process	Lipid transport Transport
Cellular component	HDL Secreted
Domain	Signal
PTM	Disulfide bond Glycoprotein
Technical term	3D-structure Complete proteome Direct protein sequencing Reference proteome
Gene Ontology (GO)
Biological process	cholesterol efflux Inferred from direct assay. Source: BHF-UCL cholesterol homeostasis Inferred by curator. Source: BHF-UCL high-density lipoprotein particle assembly Inferred from sequence or structural similarity. Source: BHF-UCL high-density lipoprotein particle clearance Inferred from sequence or structural similarity. Source: BHF-UCL high-density lipoprotein particle remodeling Inferred from mutant phenotype. Source: BHF-UCL negative regulation of plasma lipoprotein particle oxidation Inferred from direct assay. Source: BHF-UCL reverse cholesterol transport Inferred from sequence or structural similarity. Source: BHF-UCL
Cellular component	discoidal high-density lipoprotein particle Inferred from direct assay. Source: BHF-UCL integral to plasma membrane Traceable author statement. Source: ProtInc low-density lipoprotein particle Inferred from direct assay. Source: BHF-UCL spherical high-density lipoprotein particle Inferred from direct assay. Source: BHF-UCL very-low-density lipoprotein particle Inferred from direct assay. Source: BHF-UCL
Molecular function	binding Inferred from electronic annotation. Source: InterPro lipid transporter activity Inferred from direct assay. Source: BHF-UCL
Complete GO annotation...

Sequence annotation (Features)

Feature key

Position(s)

Length

Description

Graphical view

Feature identifier

Molecule processing

Chain

1 – 188

188

Apolipoprotein M

PRO_0000223278

Signal peptide

1 – ?22

22

Not cleaved Ref.1

Sites

Binding site

136

1

Fatty acid

Binding site

143

1

Fatty acid

Amino acid modifications

Glycosylation

135

1

N-linked (GlcNAc...) Ref.9 Ref.13

Disulfide bond

23 ↔ 167

Ref.15

Disulfide bond

95 ↔ 183

Ref.15

Disulfide bond

128 ↔ 157

Ref.15

Experimental info

Mutagenesis

22

1

Q → A: Introduces a signal cleavage site. Abolishes interaction with lipoprotein particles. Leads to rapid elimination from plasma. Ref.10 Ref.11 Ref.12

Mutagenesis

135

1

N → Q: Loss of glycosylation.

Mutagenesis

148

1

N → Q: No loss of glycosylation.

Sequence conflict

1 – 38

38

MFHQI…VDGKE → RFPDSIWGSRSDTSGSPQVP KLYFCGARRESPQPQT in AAF29014. Ref.3

Sequence conflict

175 – 188

14

LTPRN…ELSNN → VDS in CAB51604. Ref.2

Secondary structure

1

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

188

Helix Strand Turn

Details...

Helix

41 – 43

3

Beta strand

47 – 51

5

Beta strand

54 – 56

3

Helix

57 – 59

3

Helix

61 – 63

3

Beta strand

66 – 74

9

Beta strand

81 – 90

10

Beta strand

95 – 103

9

Beta strand

111 – 113

3

Beta strand

120 – 124

5

Beta strand

133 – 137

5

Beta strand

143 – 152

10

Helix

155 – 167

13

Sequences

	Sequence		Length	Mass (Da)
	O95445 [UniParc]. Last modified May 1, 2000. Version 2. Checksum: E4C35FEC32B7CB86	FASTA	188	21,253
	10 20 30 40 50 60 MFHQIWAALL YFYGIILNSI YQCPEHSQLT TLGVDGKEFP EVHLGQWYFI AGAAPTKEEL 70 80 90 100 110 120 ATFDPVDNIV FNMAAGSAPM QLHLRATIRM KDGLCVPRKW IYHLTEGSTD LRTEGRPDMK 130 140 150 160 170 180 TELFSSSCPG GIMLNETGQG YQRFLLYNRS PHPPEKCVEE FKSLTSCLDS KAFLLTPRNQ EACELSNN

References

	« Hide 'large scale' referencesShow 'large scale' references »
[1]	"A novel human apolipoprotein (apoM)." Xu N., Dahlbaeck B. J. Biol. Chem. 274:31286-31290(1999) [PubMed: 10531326] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [MRNA], PROTEIN SEQUENCE OF 1-15. Tissue: Liver.
[2]	"Characterisation of the novel gene G3a located in the class III region of the human major histocompatibility complex." Thomson W., Campbell R.D. Submitted (JUL-1999) to the EMBL/GenBank/DDBJ databases Cited for: NUCLEOTIDE SEQUENCE [MRNA].
[3]	"Human partial CDS from CD34+ stem cells." Ye M., Zhang Q.-H., Zhou J., Shen Y., Wu X.-Y., Guan Z.Q., Wang L., Fan H.-Y., Mao Y.-F., Dai M., Huang Q.-H., Chen S.-J., Chen Z. Submitted (MAY-1999) to the EMBL/GenBank/DDBJ databases Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA]. Tissue: Umbilical cord blood.
[4]	"Analysis of the gene-dense major histocompatibility complex class III region and its comparison to mouse." Xie T., Rowen L., Aguado B., Ahearn M.E., Madan A., Qin S., Campbell R.D., Hood L. Genome Res. 13:2621-2636(2003) [PubMed: 14656967] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
[5]	Mural R.J., Istrail S., Sutton G.G., Florea L., Halpern A.L., Mobarry C.M., Lippert R., Walenz B., Shatkay H., Dew I., Miller J.R., Flanigan M.J., Edwards N.J., Bolanos R., Fasulo D., Halldorsson B.V., Hannenhalli S., Turner R. , Yooseph S., Lu F., Nusskern D.R., Shue B.C., Zheng X.H., Zhong F., Delcher A.L., Huson D.H., Kravitz S.A., Mouchard L., Reinert K., Remington K.A., Clark A.G., Waterman M.S., Eichler E.E., Adams M.D., Hunkapiller M.W., Myers E.W., Venter J.C. Submitted (JUL-2005) to the EMBL/GenBank/DDBJ databases Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
[6]	"Homo sapiens 2,229,817bp genomic DNA of 6p21.3 HLA class I region." Shiina S., Tamiya G., Oka A., Inoko H. Submitted (SEP-1999) to the EMBL/GenBank/DDBJ databases Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
[7]	"The DNA sequence and analysis of human chromosome 6." Mungall A.J., Palmer S.A., Sims S.K., Edwards C.A., Ashurst J.L., Wilming L., Jones M.C., Horton R., Hunt S.E., Scott C.E., Gilbert J.G.R., Clamp M.E., Bethel G., Milne S., Ainscough R., Almeida J.P., Ambrose K.D., Andrews T.D. , Ashwell R.I.S., Babbage A.K., Bagguley C.L., Bailey J., Banerjee R., Barker D.J., Barlow K.F., Bates K., Beare D.M., Beasley H., Beasley O., Bird C.P., Blakey S.E., Bray-Allen S., Brook J., Brown A.J., Brown J.Y., Burford D.C., Burrill W., Burton J., Carder C., Carter N.P., Chapman J.C., Clark S.Y., Clark G., Clee C.M., Clegg S., Cobley V., Collier R.E., Collins J.E., Colman L.K., Corby N.R., Coville G.J., Culley K.M., Dhami P., Davies J., Dunn M., Earthrowl M.E., Ellington A.E., Evans K.A., Faulkner L., Francis M.D., Frankish A., Frankland J., French L., Garner P., Garnett J., Ghori M.J., Gilby L.M., Gillson C.J., Glithero R.J., Grafham D.V., Grant M., Gribble S., Griffiths C., Griffiths M.N.D., Hall R., Halls K.S., Hammond S., Harley J.L., Hart E.A., Heath P.D., Heathcott R., Holmes S.J., Howden P.J., Howe K.L., Howell G.R., Huckle E., Humphray S.J., Humphries M.D., Hunt A.R., Johnson C.M., Joy A.A., Kay M., Keenan S.J., Kimberley A.M., King A., Laird G.K., Langford C., Lawlor S., Leongamornlert D.A., Leversha M., Lloyd C.R., Lloyd D.M., Loveland J.E., Lovell J., Martin S., Mashreghi-Mohammadi M., Maslen G.L., Matthews L., McCann O.T., McLaren S.J., McLay K., McMurray A., Moore M.J.F., Mullikin J.C., Niblett D., Nickerson T., Novik K.L., Oliver K., Overton-Larty E.K., Parker A., Patel R., Pearce A.V., Peck A.I., Phillimore B.J.C.T., Phillips S., Plumb R.W., Porter K.M., Ramsey Y., Ranby S.A., Rice C.M., Ross M.T., Searle S.M., Sehra H.K., Sheridan E., Skuce C.D., Smith S., Smith M., Spraggon L., Squares S.L., Steward C.A., Sycamore N., Tamlyn-Hall G., Tester J., Theaker A.J., Thomas D.W., Thorpe A., Tracey A., Tromans A., Tubby B., Wall M., Wallis J.M., West A.P., White S.S., Whitehead S.L., Whittaker H., Wild A., Willey D.J., Wilmer T.E., Wood J.M., Wray P.W., Wyatt J.C., Young L., Younger R.M., Bentley D.R., Coulson A., Durbin R.M., Hubbard T., Sulston J.E., Dunham I., Rogers J., Beck S. Nature 425:805-811(2003) [PubMed: 14574404] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
[8]	"The status, quality, and expansion of the NIH full-length cDNA project: the Mammalian Gene Collection (MGC)." The MGC Project Team Genome Res. 14:2121-2127(2004) [PubMed: 15489334] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA]. Tissue: Liver.
[9]	"Human plasma N-glycoproteome analysis by immunoaffinity subtraction, hydrazide chemistry, and mass spectrometry." Liu T., Qian W.-J., Gritsenko M.A., Camp D.G. II, Monroe M.E., Moore R.J., Smith R.D. J. Proteome Res. 4:2070-2080(2005) [PubMed: 16335952] [Abstract] Cited for: GLYCOSYLATION [LARGE SCALE ANALYSIS] AT ASN-135, MASS SPECTROMETRY. Tissue: Plasma.
[10]	"Hydrophobic ligand binding properties of the human lipocalin apolipoprotein M." Ahnstrom J., Faber K., Axler O., Dahlback B. J. Lipid Res. 48:1754-1762(2007) [PubMed: 17525477] [Abstract] Cited for: FUNCTION, SUBCELLULAR LOCATION, MUTAGENESIS OF GLN-22.
[11]	"Apolipoprotein M associates to lipoproteins through its retained signal peptide." Axler O., Ahnstrom J., Dahlback B. FEBS Lett. 582:826-828(2008) [PubMed: 18279674] [Abstract] Cited for: SUBCELLULAR LOCATION, MUTAGENESIS OF GLN-22.
[12]	"The signal peptide anchors apolipoprotein M in plasma lipoproteins and prevents rapid clearance of apolipoprotein M from plasma." Christoffersen C., Ahnstrom J., Axler O., Christensen E.I., Dahlback B., Nielsen L.B. J. Biol. Chem. 283:18765-18772(2008) [PubMed: 18460466] [Abstract] Cited for: SUBCELLULAR LOCATION, MUTAGENESIS OF GLN-22.
[13]	"Glycoproteomics analysis of human liver tissue by combination of multiple enzyme digestion and hydrazide chemistry." Chen R., Jiang X., Sun D., Han G., Wang F., Ye M., Wang L., Zou H. J. Proteome Res. 8:651-661(2009) [PubMed: 19159218] [Abstract] Cited for: GLYCOSYLATION [LARGE SCALE ANALYSIS] AT ASN-135, MASS SPECTROMETRY. Tissue: Liver.
[14]	"Proposed lipocalin fold for apolipoprotein M based on bioinformatics and site-directed mutagenesis." Duan J., Dahlbaeck B., Villoutreix B.O. FEBS Lett. 499:127-132(2001) [PubMed: 11418126] [Abstract] Cited for: 3D-STRUCTURE MODELING, MUTAGENESIS.
[15]	"Serendipitous fatty acid binding reveals the structural determinants for ligand recognition in apolipoprotein M." Sevvana M., Ahnstrom J., Egerer-Sieber C., Lange H.A., Dahlback B., Muller Y.A. J. Mol. Biol. 393:920-936(2009) [PubMed: 19733574] [Abstract] Cited for: X-RAY CRYSTALLOGRAPHY (1.95 ANGSTROMS) OF 22-188 IN COMPLEX WITH FATTY ACIDS, DISULFIDE BONDS, FUNCTION.
+	Additional computationally mapped references.

Cross-references

Sequence databases

EMBL
GenBank
DDBJ

AF118393 mRNA. Translation: AAD11443.2.
AJ245434 mRNA. Translation: CAB51604.1.
AF161454 mRNA. Translation: AAF29014.1.
AF129756 Genomic DNA. Translation: AAD18084.1.
BA000025 Genomic DNA. Translation: BAB63389.1.
AL662801 Genomic DNA. Translation: CAI18319.1.
AL670886 Genomic DNA. Translation: CAI17788.1.
AL805934 Genomic DNA. Translation: CAI18511.1.
BX511262 Genomic DNA. Translation: CAM45814.1.
CR753842 Genomic DNA. Translation: CAQ06561.1.
CR354443 Genomic DNA. Translation: CAQ06991.1.
CR759761 Genomic DNA. Translation: CAQ10868.1.
CH471081 Genomic DNA. Translation: EAX03463.1.
BC020683 mRNA. Translation: AAH20683.1.

IPI

IPI00030739.

RefSeq

NP_061974.2. NM_019101.2.

UniGene

Hs.534468.

3D structure databases

PDBe
RCSB PDB
PDBj

Entry	Method	Resolution (Å)	Chain	Positions	PDBsum
2WEW	X-ray	1.95	A	22-188	[»]
2WEX	X-ray	2.00	A	22-188	[»]
2YG2	X-ray	1.70	A/B	22-188	[»]

ProteinModelPortal

O95445.

SMR

O95445. Positions 22-187.

ModBase

Search...

Protein-protein interaction databases

IntAct

O95445. 2 interactions.

MINT

MINT-1379248.

Proteomic databases

PeptideAtlas

O95445.

PRIDE

O95445.

Protocols and materials databases

StructuralBiologyKnowledgebase

Search...

Genome annotation databases

Ensembl

ENST00000375916; ENSP00000365081; ENSG00000204444.
ENST00000383438; ENSP00000372930; ENSG00000206409.
ENST00000426800; ENSP00000405730; ENSG00000227567.
ENST00000430282; ENSP00000401684; ENSG00000224290.
ENST00000432598; ENSP00000389591; ENSG00000235754.
ENST00000436931; ENSP00000394610; ENSG00000231974.
ENST00000441436; ENSP00000398944; ENSG00000226215.

GeneID

55937.

KEGG

hsa:55937.

UCSC

uc003nvl.1. human.

Organism-specific databases

CTD

55937.

GeneCards

GC06P031620.

HGNC

HGNC:13916. APOM.

MIM

606907. gene.

neXtProt

NX_O95445.

PharmGKB

PA38370.

GenAtlas

Search...

Phylogenomic databases

eggNOG

prNOG06527.

HOGENOM

HBG269397.

HOVERGEN

HBG018735.

InParanoid

O95445.

OMA

PRNQEAC.

Gene expression databases

CleanEx

HS_APOM.

Genevestigator

O95445.

GermOnline

ENSG00000204444. Homo sapiens.

Family and domain databases

InterPro

IPR022734. ApoM.
IPR012674. Calycin.
IPR011038. Calycin-like.
[Graphical view]

Gene3D

G3DSA:2.40.128.20. Calycin. 1 hit.

Pfam

PF11032. ApoM. 1 hit.
[Graphical view]

SUPFAM

SSF50814. Calycin. 1 hit.

ProtoNet

Search...

Other

NextBio

61349.

SOURCE

Search...

Entry information

Entry name

APOM_HUMAN

Accession

Primary (citable) accession number: O95445
Secondary accession number(s): B0UX98, Q9P046, Q9UMP6

Entry history

Integrated into UniProtKB/Swiss-Prot:	September 26, 2001
Last sequence update:	May 1, 2000
Last modified:	January 25, 2012
This is version 108 of the entry and version 2 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation program

Chordata Protein Annotation Program

Disclaimer

Any 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.