Reviewed, UniProtKB/Swiss-Prot Q9BUR5 (APOO_HUMAN)

Names and origin

Protein names

Recommended name:
    Apolipoprotein O
Alternative name(s):
    Protein FAM121B

Gene names

Name:	APOO
Synonyms:	FAM121B
ORF Names:	My025, UNQ1866/PRO4302

Organism

Homo sapiens (Human) [Complete proteome]

Taxonomic identifier

9606 [NCBI]

Taxonomic lineage

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

Protein attributes

Sequence length	198 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	Promotes cholesterol efflux from macrophage cells. Detected in HDL, LDL and VLDL. Secreted by a microsomal triglyceride transfer protein (MTTP)-dependent mechanism, probably as a VLDL-associated protein that is subsequently transferred to HDL. May be involved in myocardium-protective mechanisms against lipid accumulation. Ref.6
Subcellular location	Membrane; Single-pass membrane protein Potential. Secreted.
Tissue specificity	Expressed in all tissues examined. Up-regulated in diabetic heart. Ref.6
Post-translational modification	O-glycosylation; glycosaminoglycan of chondroitin-sulfate type.
Sequence similarities	Belongs to the apolipoprotein O family.

Ontologies

Keywords
Biological process	Lipid transport Transport
Cellular component	HDL LDL Membrane Secreted VLDL
Coding sequence diversity	Alternative splicing
Domain	Signal Transmembrane
PTM	Glycoprotein Proteoglycan
Technical term	Complete proteome
Gene Ontology (GO)
Biological process	lipid transport Inferred from electronic annotation. Source: UniProtKB-KW
Cellular component	high-density lipoprotein particle Inferred from electronic annotation. Source: UniProtKB-KW integral to membrane Inferred from electronic annotation. Source: UniProtKB-SubCell low-density lipoprotein particle Inferred from electronic annotation. Source: UniProtKB-KW very-low-density lipoprotein particle Inferred from electronic annotation. Source: UniProtKB-KW
Complete GO annotation...

Alternative products

This entry describes 2 isoforms produced by alternative splicing. [Align] [Select]

Isoform 1 (identifier: Q9BUR5-1)

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.

Isoform 2 (identifier: Q9BUR5-2)

The sequence of this isoform differs from the canonical sequence as follows:
     80-109: ETYSQTKPKMQSLVQWGLDSYDYLQNAPPG → TAMTISKMHLLD

Sequence annotation (Features)

	Feature key	Position(s)	Length	Description	Graphical view	Feature identifier
Molecule processing
	Signal peptide	1 – 25	25	Potential
	Chain	26 – 198	173	Apolipoprotein O		PRO_0000254646
Regions
	Transmembrane	108 – 128	21	Potential
Amino acid modifications
	Glycosylation	162	1	O-linked (Xyl...) (chondroitin sulfate) Potential
Natural variations
	Alternative sequence	80 – 109	30	ETYSQ…NAPPG → TAMTISKMHLLD in isoform 2.		VSP_023333

Sequences

	Sequence		Length	Mass (Da)
	Isoform 1 [UniParc]. Last modified June 1, 2001. Version 1. Checksum: BEC99607F54E98E2	FASTA	198	22,285
	10 20 30 40 50 60 MFKVIQRSVG PASLSLLTFK VYAAPKKDSP PKNSVKVDEL SLYSVPEGQS KYVEEARSQL 70 80 90 100 110 120 EESISQLRHY CEPYTTWCQE TYSQTKPKMQ SLVQWGLDSY DYLQNAPPGF FPRLGVIGFA 130 140 150 160 170 180 GLIGLLLARG SKIKKLVYPP GFMGLAASLY YPQQAIVFAQ VSGERLYDWG LRGYIVIEDL 190 WKENFQKPGN VKNSPGTK
	Isoform 2. Checksum: 0612F903AB6390E1	FASTA	180	20,199
	10 20 30 40 50 60 MFKVIQRSVG PASLSLLTFK VYAAPKKDSP PKNSVKVDEL SLYSVPEGQS KYVEEARSQL 70 80 90 100 110 120 EESISQLRHY CEPYTTWCQT AMTISKMHLL DFFPRLGVIG FAGLIGLLLA RGSKIKKLVY 130 140 150 160 170 180 PPGFMGLAAS LYYPQQAIVF AQVSGERLYD WGLRGYIVIE DLWKENFQKP GNVKNSPGTK

References

	« Hide 'large scale' referencesShow 'large scale' references »
[1]	Mao Y.M., Xie Y., Zheng Z.H. Submitted (APR-1998) to the EMBL/GenBank/DDBJ databases Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA] (ISOFORM 2). Tissue: Fetal brain.
[2]	"The secreted protein discovery initiative (SPDI), a large-scale effort to identify novel human secreted and transmembrane proteins: a bioinformatics assessment." Clark H.F., Gurney A.L., Abaya E., Baker K., Baldwin D.T., Brush J., Chen J., Chow B., Chui C., Crowley C., Currell B., Deuel B., Dowd P., Eaton D., Foster J.S., Grimaldi C., Gu Q., Hass P.E. , Heldens S., Huang A., Kim H.S., Klimowski L., Jin Y., Johnson S., Lee J., Lewis L., Liao D., Mark M.R., Robbie E., Sanchez C., Schoenfeld J., Seshagiri S., Simmons L., Singh J., Smith V., Stinson J., Vagts A., Vandlen R.L., Watanabe C., Wieand D., Woods K., Xie M.-H., Yansura D.G., Yi S., Yu G., Yuan J., Zhang M., Zhang Z., Goddard A.D., Wood W.I., Godowski P.J., Gray A.M. Genome Res. 13:2265-2270(2003) [PubMed: 12975309] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA] (ISOFORM 1).
[3]	"Complete sequencing and characterization of 21,243 full-length human cDNAs." Ota T., Suzuki Y., Nishikawa T., Otsuki T., Sugiyama T., Irie R., Wakamatsu A., Hayashi K., Sato H., Nagai K., Kimura K., Makita H., Sekine M., Obayashi M., Nishi T., Shibahara T., Tanaka T., Ishii S. , Yamamoto J., Saito K., Kawai Y., Isono Y., Nakamura Y., Nagahari K., Murakami K., Yasuda T., Iwayanagi T., Wagatsuma M., Shiratori A., Sudo H., Hosoiri T., Kaku Y., Kodaira H., Kondo H., Sugawara M., Takahashi M., Kanda K., Yokoi T., Furuya T., Kikkawa E., Omura Y., Abe K., Kamihara K., Katsuta N., Sato K., Tanikawa M., Yamazaki M., Ninomiya K., Ishibashi T., Yamashita H., Murakawa K., Fujimori K., Tanai H., Kimata M., Watanabe M., Hiraoka S., Chiba Y., Ishida S., Ono Y., Takiguchi S., Watanabe S., Yosida M., Hotuta T., Kusano J., Kanehori K., Takahashi-Fujii A., Hara H., Tanase T.-O., Nomura Y., Togiya S., Komai F., Hara R., Takeuchi K., Arita M., Imose N., Musashino K., Yuuki H., Oshima A., Sasaki N., Aotsuka S., Yoshikawa Y., Matsunawa H., Ichihara T., Shiohata N., Sano S., Moriya S., Momiyama H., Satoh N., Takami S., Terashima Y., Suzuki O., Nakagawa S., Senoh A., Mizoguchi H., Goto Y., Shimizu F., Wakebe H., Hishigaki H., Watanabe T., Sugiyama A., Takemoto M., Kawakami B., Yamazaki M., Watanabe K., Kumagai A., Itakura S., Fukuzumi Y., Fujimori Y., Komiyama M., Tashiro H., Tanigami A., Fujiwara T., Ono T., Yamada K., Fujii Y., Ozaki K., Hirao M., Ohmori Y., Kawabata A., Hikiji T., Kobatake N., Inagaki H., Ikema Y., Okamoto S., Okitani R., Kawakami T., Noguchi S., Itoh T., Shigeta K., Senba T., Matsumura K., Nakajima Y., Mizuno T., Morinaga M., Sasaki M., Togashi T., Oyama M., Hata H., Watanabe M., Komatsu T., Mizushima-Sugano J., Satoh T., Shirai Y., Takahashi Y., Nakagawa K., Okumura K., Nagase T., Nomura N., Kikuchi H., Masuho Y., Yamashita R., Nakai K., Yada T., Nakamura Y., Ohara O., Isogai T., Sugano S. Nat. Genet. 36:40-45(2004) [PubMed: 14702039] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA] (ISOFORM 1). Tissue: Brain.
[4]	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].
[5]	"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] (ISOFORM 1). Tissue: Lung, Skin and Urinary bladder.
[6]	"ApoO, a novel apolipoprotein, is an original glycoprotein up-regulated by diabetes in human heart." Lamant M., Smih F., Harmancey R., Philip-Couderc P., Pathak A., Roncalli J., Galinier M., Collet X., Massabuau P., Senard J.-M., Rouet P. J. Biol. Chem. 281:36289-36302(2006) [PubMed: 16956892] [Abstract] Cited for: FUNCTION, SUBCELLULAR LOCATION, TISSUE SPECIFICITY, COVALENT LINKAGE WITH CHONDROITIN SULFATE.
[7]	Colinge J., Superti-Furga G., Bennett K.L. Submitted (OCT-2008) to UniProtKB Cited for: IDENTIFICATION [LARGE SCALE ANALYSIS], MASS SPECTROMETRY.
+	Additional computationally mapped references.

Cross-references

Sequence databases
EMBLGenBankDDBJ	AF061264 mRNA. Translation: AAG43139.1. AY359114 mRNA. Translation: AAQ89472.1. AK311865 mRNA. Translation: BAG34806.1. CH471074 Genomic DNA. Translation: EAW99002.1. BC002333 mRNA. Translation: AAH02333.1. BC010102 mRNA. Translation: AAH10102.1. BC016814 mRNA. Translation: AAH16814.1.
IPI	IPI00042580. IPI00797546.
RefSeq	NP_077027.1.
UniGene	Hs.495851
3D structure databases
ModBase	Search...
Proteomic databases
PeptideAtlas	Q9BUR5.
PRIDE	Q9BUR5.
Genome annotation databases
Ensembl	ENST00000379226; ENSP00000368528; ENSG00000184831; Homo sapiens. [Genome view]
GeneID	79135.
KEGG	hsa:79135.
UCSC	uc004dax.1. human.
Organism-specific databases
CTD	79135.
GeneCards	GC0XM023763.
HGNC	HGNC:28727. APOO.
HPA	HPA003187.
MIM	300753. gene.
GenAtlas	Search...
Phylogenomic databases
HOVERGEN	Q9BUR5.
OMA	SISHLRH
Gene expression databases
ArrayExpress	Q9BUR5.
Bgee	Q9BUR5.
CleanEx	HS_APOO.
Genevestigator	Q9BUR5.
GermOnline	ENSG00000184831. Homo sapiens.
Family and domain databases
InterPro	IPR019166. Apolipoprotein_O. [Graphical view]
Pfam	PF09769. ApoO. 1 hit. [Graphical view]
ProtoNet	Search...
Other Resources
NextBio	68006.
SOURCE	Search...

Entry information

Entry name

APOO_HUMAN

Accession

Primary (citable) accession number: Q9BUR5
Secondary accession number(s): B2R4K9, Q9H3J9

Entry history

Integrated into UniProtKB/Swiss-Prot:	October 31, 2006
Last sequence update:	June 1, 2001
Last modified:	November 24, 2009
This is version 53 of the entry and version 1 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation project

HPI (Human Proteome Initiative)

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.