P02654 (APOC1_HUMAN) Reviewed, UniProtKB/Swiss-Prot

Names and origin

Protein names

Recommended name:
Apolipoprotein C-I
Short name=Apo-CIB
Short name=ApoC-IB

Alternative name(s):
Apolipoprotein C1

Cleaved into the following chain:

1. Truncated apolipoprotein C-I
   Short name=Apo-CIB'
   Short name=ApoC-IB'

Gene names

Name:	APOC1
Synonyms:	APOC1B

Organism

Homo sapiens (Human) [Reference proteome]

Taxonomic identifier

9606 [NCBI]

Taxonomic lineage

cellular organisms › Eukaryota › Opisthokonta › Metazoa › Eumetazoa › Bilateria › Deuterostomia › Chordata › Craniata › Vertebrata › Gnathostomata › Teleostomi › Euteleostomi › Sarcopterygii › Tetrapoda › Amniota › Mammalia › Theria › Eutheria › Euarchontoglires › Primates › Haplorrhini › Simiiformes › Catarrhini › Hominoidea › Hominidae › Homininae › Homo

Protein attributes

Sequence length	83 AA.
Sequence status	Complete.
Sequence processing	The displayed sequence is further processed into a mature form.
Protein existence	Evidence at protein level

General annotation (Comments)

Function	Appears to modulate the interaction of APOE with beta-migrating VLDL and inhibit binding of beta-VLDL to the LDL receptor-related protein. Binds free fatty acids and reduces their intracellular esterification. Ref.13
Subcellular location	Secreted.
Tissue specificity	Synthesized mainly in liver and to a minor degree in intestine. Secreted in plasma.
Miscellaneous	Apolipoprotein C-I is present in acidic (APOC1A) and basic (APOC1B) forms in P.paniscus, P.abelii and P.troglodytes and perhaps also in baboons and macaques. In human, the acidic form has become a pseudogene. Apo-CI makes up about 10% of the protein of the VLDL (very low density lipoprotein) and 2% of that of HDL (high density lipoprotein).
Sequence similarities	Belongs to the apolipoprotein C1 family.

Ontologies

Keywords
Biological process	Lipid transport Transport
Cellular component	Secreted VLDL
Coding sequence diversity	Polymorphism
Domain	Signal
Technical term	3D-structure Complete proteome Direct protein sequencing Reference proteome
Gene Ontology (GO)
Biological_process	cholesterol efflux Inferred from direct assay PubMed 11162594. Source: BHF-UCL chylomicron remnant clearance Inferred from direct assay PubMed 4020294. Source: BHF-UCL high-density lipoprotein particle remodeling Traceable author statement PubMed 18992221. Source: BHF-UCL lipid metabolic process Traceable author statement Ref.12. Source: ProtInc lipoprotein metabolic process Inferred from electronic annotation. Source: InterPro negative regulation of cholesterol transport Inferred from direct assay PubMed 10978346. Source: BHF-UCL negative regulation of fatty acid biosynthetic process Inferred from direct assay PubMed 15576844. Source: BHF-UCL negative regulation of lipoprotein lipase activity Inferred from direct assay PubMed 15576844. Source: BHF-UCL negative regulation of phosphatidylcholine catabolic process Inferred from direct assay PubMed 2302419. Source: BHF-UCL negative regulation of receptor-mediated endocytosis Inferred from direct assay PubMed 1917954. Source: BHF-UCL negative regulation of very-low-density lipoprotein particle clearance Inferred from direct assay PubMed 1917954. Source: BHF-UCL phospholipid efflux Inferred from direct assay PubMed 11162594. Source: BHF-UCL positive regulation of cholesterol esterification Traceable author statement PubMed 18992221. Source: BHF-UCL very-low-density lipoprotein particle assembly Traceable author statement PubMed 18992221. Source: BHF-UCL very-low-density lipoprotein particle clearance Inferred from genetic interaction PubMed 15576844. Source: BHF-UCL
Cellular_component	chylomicron Traceable author statement PubMed 18992221. Source: BHF-UCL endoplasmic reticulum Inferred from direct assay. Source: LIFEdb high-density lipoprotein particle Inferred from direct assay PubMed 15576844. Source: BHF-UCL very-low-density lipoprotein particle Inferred from direct assay PubMed 15576844. Source: BHF-UCL
Molecular_function	fatty acid binding Inferred from direct assay Ref.13. Source: BHF-UCL phosphatidylcholine binding Traceable author statement PubMed 2302419. Source: BHF-UCL phosphatidylcholine-sterol O-acyltransferase activator activity Traceable author statement PubMed 18992221. Source: BHF-UCL phospholipase inhibitor activity Inferred from direct assay PubMed 2302419. Source: BHF-UCL
Complete GO annotation...

Sequence annotation (Features)

Feature key

Position(s)

Length

Description

Graphical view

Feature identifier

Molecule processing

Signal peptide

1 – 26

26

Ref.10 Ref.11

Chain

27 – 83

57

Apolipoprotein C-I

PRO_0000002014

Chain

29 – 83

55

Truncated apolipoprotein C-I By similarity

PRO_0000391843

Natural variations

Natural variant

16

1

I → M. Ref.16
Corresponds to variant rs5112 [ dbSNP | Ensembl ].

VAR_014183

Natural variant

71

1

T → S Polymorphism found only in persons of American Indian or Mexican ancestry; more susceptible to N-terminal truncation and shows greater distribution to the VLDL than the protein with T-71. Ref.17

VAR_029011

Secondary structure

1

.

.

.

.

.

.

.

.

.

.

.

.

83

Helix Strand Turn

Details...

Beta strand

31 – 33

3

Helix

35 – 48

14

Turn

52 – 54

3

Beta strand

56 – 62

7

Helix

65 – 78

14

Beta strand

79 – 81

3

Sequences

	Sequence		Length	Mass (Da)
	P02654 [UniParc]. Last modified October 23, 1986. Version 1. Checksum: 4A3614626624AE6A	FASTA	83	9,332
	10 20 30 40 50 60 MRLFLSLPVL VVVLSIVLEG PAPAQGTPDV SSALDKLKEF GNTLEDKARE LISRIKQSEL 70 80 SAKMREWFSE TFQKVKEKLK IDS

References

	« Hide 'large scale' referencesShow 'large scale' references »
[1]	"Characterisation of mRNAs encoding the precursor for human apolipoprotein CI." Knott T.J., Robertson M.E., Priestley L.M., Urdea M., Wallis S.C., Scott J. Nucleic Acids Res. 12:3909-3915(1984) [PubMed] [Europe PMC] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [MRNA].
[2]	"Two copies of the human apolipoprotein C-I gene are linked closely to the apolipoprotein E gene." Lauer S.J., Walker D., Elshourbagy N.A., Reardon C.A., Levy-Wilson B., Taylor J.M. J. Biol. Chem. 263:7277-7286(1988) [PubMed] [Europe PMC] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA].
[3]	"Sequencing of 42kb of the APO E-C2 gene cluster reveals a new gene: PEREC1." Freitas E.M., Zhang W.J., Lalonde J.P., Tay G.K., Gaudieri S., Ashworth L.K., Van Bockxmeer F.M., Dawkins R.L. DNA Seq. 9:89-100(1998) [PubMed] [Europe PMC] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA].
[4]	Nickerson D.A., Smith J.D., Fullerton S.M., Clark A.G., Stengard J.H., Salomaa V., Boerwinkle E., Sing C.F., Weiss K.M. Submitted (SEP-2003) to the EMBL/GenBank/DDBJ databases Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA].
[5]	"Cloning of human full-length CDSs in BD Creator(TM) system donor vector." Kalnine N., Chen X., Rolfs A., Halleck A., Hines L., Eisenstein S., Koundinya M., Raphael J., Moreira D., Kelley T., LaBaer J., Lin Y., Phelan M., Farmer A. Submitted (MAY-2003) to the EMBL/GenBank/DDBJ databases Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA].
[6]	"Cloning of human full open reading frames in Gateway(TM) system entry vector (pDONR201)." Ebert L., Schick M., Neubert P., Schatten R., Henze S., Korn B. Submitted (JUN-2004) to the EMBL/GenBank/DDBJ databases Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA].
[7]	Bechtel S., Schupp I., Duda A., Wellenreuther R., Mehrle A., Ruschke V., Poustka A., Wiemann S. Submitted (JUL-2006) to the EMBL/GenBank/DDBJ databases Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA].
[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] [Europe PMC] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA]. Tissue: Lung.
[9]	"Isolation and characterisation of a cDNA clone for human apolipoprotein CI and assignment of the gene to chromosome 19." Tata F., Henry I., Markham A.F., Wallis S.C., Weil D., Grzeschik K.H., Junien C., Williamson R., Humphries S.E. Hum. Genet. 69:345-349(1985) [PubMed] [Europe PMC] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [MRNA] OF 15-83.
[10]	"The complete amino acid sequence of C-I (apoLp-Ser), an apolipoprotein from human very low density lipoproteins." Shulman R.S., Herbert P.N., Wehrly K., Fredrickson D.S. J. Biol. Chem. 250:182-190(1975) [PubMed] [Europe PMC] [Abstract] Cited for: PROTEIN SEQUENCE OF 27-83.
[11]	"The primary structure of apolipoprotein-serine." Jackson R.L., Sparrow J.T., Baker H.N., Morrisett J.D., Taunton O.D., Gotto A.M. Jr. J. Biol. Chem. 249:5308-5313(1974) [PubMed] [Europe PMC] [Abstract] Cited for: PROTEIN SEQUENCE OF 27-83.
[12]	"Exact localization of the familial dysbetalipoproteinemia associated HpaI restriction site in the promoter region of the APOC1 gene." Smit M.V.D., Kooij-Meijs E., Woudt L.P., Havekes L.M., Frants R.R. Biochem. Biophys. Res. Commun. 152:1282-1288(1988) [PubMed] [Europe PMC] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA] OF 1-19.
[13]	"Apolipoprotein C-I binds free fatty acids and reduces their intracellular esterification." Westerterp M., Berbee J.F., Delsing D.J., Jong M.C., Gijbels M.J., Dahlmans V.E., Offerman E.H., Romijn J.A., Havekes L.M., Rensen P.C. J. Lipid Res. 48:1353-1361(2007) [PubMed] [Europe PMC] [Abstract] Cited for: FUNCTION.
[14]	"Conformation of two peptides corresponding to human apolipoprotein C-I residues 7-24 and 35-53 in the presence of sodium dodecyl sulfate by CD and NMR spectroscopy." Rozek A., Buchko G.W., Cushley R.J. Biochemistry 34:7401-7408(1995) [PubMed] [Europe PMC] [Abstract] Cited for: STRUCTURE BY NMR OF 33-50 AND 61-79.
[15]	"Conformational studies of the N-terminal lipid-associating domain of human apolipoprotein C-I by CD and 1H NMR spectroscopy." Rozek A., Buchko G.W., Kanda P., Cushley R.J. Protein Sci. 6:1858-1868(1997) [PubMed] [Europe PMC] [Abstract] Cited for: STRUCTURE BY NMR OF 27-64.
[16]	"Patterns of single-nucleotide polymorphisms in candidate genes for blood-pressure homeostasis." Halushka M.K., Fan J.-B., Bentley K., Hsie L., Shen N., Weder A., Cooper R., Lipshutz R., Chakravarti A. Nat. Genet. 22:239-247(1999) [PubMed] [Europe PMC] [Abstract] Cited for: VARIANT MET-16.
[17]	"A functional polymorphism of apolipoprotein C1 detected by mass spectrometry." Wroblewski M.S., Wilson-Grady J.T., Martinez M.B., Kasthuri R.S., McMillan K.R., Flood-Urdangarin C., Nelsestuen G.L. FEBS J. 273:4707-4715(2006) [PubMed] [Europe PMC] [Abstract] Cited for: VARIANT SER-71, CHARACTERIZATION OF VARIANT SER-71.
+	Additional computationally mapped references.

Web resources

Wikipedia

Apolipoprotein C1 entry

Cross-references

Sequence databases

EMBL
GenBank
DDBJ

X00570 mRNA. Translation: CAA25235.1.
M20843 Genomic DNA. Translation: AAA51763.1.
AF050154 Genomic DNA. Translation: AAD02506.1.
AY422954 Genomic DNA. Translation: AAQ91813.1.
BT007142 mRNA. Translation: AAP35806.1.
CR456907 mRNA. Translation: CAG33188.1.
AM392727 mRNA. Translation: CAL37605.1.
BC009698 mRNA. Translation: AAH09698.1.
BC055093 mRNA. Translation: AAH55093.1.
M20902 Genomic DNA. Translation: AAA88018.1.
M27359 mRNA. Translation: AAA51762.1.

IPI

IPI00021855.

PIR

LPHUC1. A28057.

RefSeq

NP_001636.1. NM_001645.3.

UniGene

Hs.110675.

3D structure databases

PDBe
RCSB PDB
PDBj

Entry	Method	Resolution (Å)	Chain	Positions	PDBsum
1ALE	NMR	-	A	33-50	[»]
1ALF	NMR	-	A	61-79	[»]
1IOJ	NMR	-	A	27-83	[»]
1OPP	NMR	-	A	27-64	[»]

ProteinModelPortal

P02654.

ModBase

Search...

Protein-protein interaction databases

IntAct

P02654. 4 interactions.

STRING

9606.ENSP00000252491.

PTM databases

PhosphoSite

P02654.

Polymorphism databases

DMDM

114016.

Proteomic databases

PaxDb

P02654.

PeptideAtlas

P02654.

PRIDE

P02654.

Protocols and materials databases

DNASU

341.

StructuralBiologyKnowledgebase

Search...

Genome annotation databases

Ensembl

ENST00000252491; ENSP00000252491; ENSG00000130208.
ENST00000588750; ENSP00000465356; ENSG00000130208.
ENST00000588802; ENSP00000468029; ENSG00000130208.

GeneID

341.

KEGG

hsa:341.

UCSC

uc002pac.1. human.

Organism-specific databases

CTD

341.

GeneCards

GC19P045417.

HGNC

HGNC:607. APOC1.

HPA

HPA051518.

MIM

107710. gene.

neXtProt

NX_P02654.

PharmGKB

PA51.

GenAtlas

Search...

Phylogenomic databases

eggNOG

NOG47204.

HOGENOM

HOG000034001.

HOVERGEN

HBG050547.

InParanoid

P02654.

OMA

NTLEDKA.

OrthoDB

EOG4K0QQ3.

PhylomeDB

P02654.

Gene expression databases

ArrayExpress

P02654.

Bgee

P02654.

CleanEx

HS_APOC1.

Genevestigator

P02654.

Family and domain databases

InterPro

IPR006781. ApoC-I.
[Graphical view]

PANTHER

PTHR16565. PTHR16565. 1 hit.

Pfam

PF04691. ApoC-I. 1 hit.
[Graphical view]

ProtoNet

Search...

Other

ChiTaRS

APOC1. human.

EvolutionaryTrace

P02654.

GenomeRNAi

341.

NextBio

1409.

SOURCE

Search...

Entry information

Entry name

APOC1_HUMAN

Accession

Primary (citable) accession number: P02654
Secondary accession number(s): Q6IB97

Entry history

Integrated into UniProtKB/Swiss-Prot:	July 21, 1986
Last sequence update:	October 23, 1986
Last modified:	May 1, 2013
This is version 136 of the entry and version 1 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.