Q9Y6B6 (SAR1B_HUMAN) Reviewed, UniProtKB/Swiss-Prot

Names and origin

Protein names

Recommended name:
GTP-binding protein SAR1b

Alternative name(s):
GTP-binding protein B
Short name=GTBPB

Gene names

Name:	SAR1B
Synonyms:	SARA2, SARB

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	198 AA.
Sequence status	Complete.
Protein existence	Evidence at protein level

General annotation (Comments)

Function	Involved in transport from the endoplasmic reticulum to the Golgi apparatus. Activated by the guanine nucleotide exchange factor PREB. Involved in the selection of the protein cargo and the assembly of the COPII coat complex.
Subunit structure	Homodimer. Binds PREB. Part of the COPII coat complex. Binds to the cytoplasmic tails of target proteins in the endoplasmic reticulum By similarity.
Subcellular location	Endoplasmic reticulum membrane; Peripheral membrane protein By similarity. Golgi apparatus › Golgi stack membrane; Peripheral membrane protein By similarity. Note: Associated with the endoplasmic reticulum and Golgi stacks, in particular in the juxta-nuclear Golgi region By similarity.
Tissue specificity	Expressed in many tissues including small intestine, liver, muscle and brain.
Involvement in disease	Chylomicron retention disease (CMRD) [MIM:246700]: An autosomal recessive disorder of severe fat malabsorption associated with failure to thrive in infancy. The condition is characterized by deficiency of fat-soluble vitamins, low blood cholesterol levels, and a selective absence of chylomicrons from blood. Affected individuals accumulate chylomicron-like particles in membrane-bound compartments of enterocytes, which contain large cytosolic lipid droplets. Note: The disease is caused by mutations affecting the gene represented in this entry. Ref.6 Ref.7 Ref.8
Sequence similarities	Belongs to the small GTPase superfamily. SAR1 family.

Ontologies

Keywords
Biological process	ER-Golgi transport Protein transport Transport
Cellular component	Endoplasmic reticulum Golgi apparatus Membrane
Disease	Disease mutation
Ligand	GTP-binding Magnesium Metal-binding Nucleotide-binding
Technical term	Complete proteome Reference proteome
Gene Ontology (GO)
Biological_process	COPII vesicle coating Traceable author statement. Source: Reactome antigen processing and presentation of exogenous peptide antigen via MHC class II Traceable author statement. Source: Reactome antigen processing and presentation of peptide antigen via MHC class I Traceable author statement. Source: Reactome intracellular protein transport Inferred from electronic annotation. Source: InterPro post-translational protein modification Traceable author statement. Source: Reactome protein N-linked glycosylation via asparagine Traceable author statement. Source: Reactome
Cellular_component	ER to Golgi transport vesicle membrane Traceable author statement. Source: Reactome Golgi cisterna membrane Inferred from electronic annotation. Source: UniProtKB-SubCell cytosol Traceable author statement. Source: Reactome endoplasmic reticulum membrane Traceable author statement. Source: Reactome
Molecular_function	GTP binding Inferred from electronic annotation. Source: UniProtKB-KW GTPase activity Traceable author statement. Source: Reactome metal ion binding Inferred from electronic annotation. Source: UniProtKB-KW
Complete GO annotation...

Sequence annotation (Features)

	Feature key	Position(s)	Length	Description	Graphical view	Feature identifier
Molecule processing
	Chain	1 – 198	198	GTP-binding protein SAR1b		PRO_0000206261
Regions
	Nucleotide binding	32 – 39	8	GTP By similarity
	Nucleotide binding	75 – 78	4	GTP By similarity
	Nucleotide binding	134 – 137	4	GTP By similarity
Sites
	Metal binding	34	1	Magnesium By similarity
	Metal binding	75	1	Magnesium By similarity
Natural variations
	Natural variant	11	1	G → D in CMRD. Ref.8		VAR_059051
	Natural variant	37	1	G → R in CMRD; loss of GDP/GTP-binding. Ref.6		VAR_016806
	Natural variant	75	1	D → G in CMRD. Ref.8		VAR_059052
	Natural variant	137	1	D → N in CMRD; reduced affinity for GDP/GTP. Ref.6 Corresponds to variant rs28942109 [ dbSNP | Ensembl ].		VAR_016807
	Natural variant	179	1	S → R in CMRD; loss of GDP/GTP-binding. Ref.6 Corresponds to variant rs28942110 [ dbSNP | Ensembl ].		VAR_016808

Sequences

	Sequence		Length	Mass (Da)
	Q9Y6B6 [UniParc]. Last modified November 1, 1999. Version 1. Checksum: 3F567683D7F509E6	FASTA	198	22,410
	10 20 30 40 50 60 MSFIFDWIYS GFSSVLQFLG LYKKTGKLVF LGLDNAGKTT LLHMLKDDRL GQHVPTLHPT 70 80 90 100 110 120 SEELTIAGMT FTTFDLGGHV QARRVWKNYL PAINGIVFLV DCADHERLLE SKEELDSLMT 130 140 150 160 170 180 DETIANVPIL ILGNKIDRPE AISEERLREM FGLYGQTTGK GSISLKELNA RPLEVFMCSV 190 LKRQGYGEGF RWMAQYID

References

	« Hide 'large scale' referencesShow 'large scale' references »
[1]	Song H., Peng Y., Dai M., Huang Q., Mao Y., Zhang Q., Mao M., Fu G., Luo M., Chen J., Hu R. Submitted (SEP-1998) to the EMBL/GenBank/DDBJ databases Cited for: NUCLEOTIDE SEQUENCE [MRNA]. Tissue: Pituitary tumor.
[2]	"Cloning of a novel human cDNA homologous to murine GTP-binding protein homologue mRNA." Zhou Y., Yu L., Gao J., Zhang P.Z., Wang X.K., Zhao S.Y. Submitted (JUL-2003) to the EMBL/GenBank/DDBJ databases Cited for: NUCLEOTIDE SEQUENCE [MRNA].
[3]	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 (SEP-2005) to the EMBL/GenBank/DDBJ databases Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
[4]	"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: Placenta.
[5]	"Initial characterization of the human central proteome." Burkard T.R., Planyavsky M., Kaupe I., Breitwieser F.P., Buerckstuemmer T., Bennett K.L., Superti-Furga G., Colinge J. BMC Syst. Biol. 5:17-17(2011) [PubMed] [Europe PMC] [Abstract] Cited for: IDENTIFICATION BY MASS SPECTROMETRY [LARGE SCALE ANALYSIS].
[6]	"Mutations in a Sar1 GTPase of COPII vesicles are associated with lipid absorption disorders." Jones B., Jones E.L., Bonney S.A., Patel H.N., Mensenkamp A.R., Eichenbaum-Voline S., Rudling M., Myrdal U., Annesi G., Naik S., Meadows N., Quattrone A., Islam S.A., Naoumova R.P., Angelin B., Infante R., Levy E., Roy C.C. , Freemont P.S., Scott J., Shoulders C.C. Nat. Genet. 34:29-31(2003) [PubMed] [Europe PMC] [Abstract] Cited for: VARIANTS CMRD ARG-37; ASN-137 AND ARG-179.
[7]	"SIL1 and SARA2 mutations in Marinesco-Sjogren and chylomicron retention diseases." Annesi G., Aguglia U., Tarantino P., Annesi F., De Marco E.V., Civitelli D., Torroni A., Quattrone A. Clin. Genet. 71:288-289(2007) [PubMed] [Europe PMC] [Abstract] Cited for: INVOLVEMENT IN CMRD BUT NOT IN MSS.
[8]	"Novel missense mutations of SAR1B gene in an infant with chylomicron retention disease." Treepongkaruna S., Chongviriyaphan N., Suthutvoravut U., Charoenpipop D., Choubtum L., Wattanasirichaigoon D. J. Pediatr. Gastroenterol. Nutr. 48:370-373(2009) [PubMed] [Europe PMC] [Abstract] Cited for: VARIANTS CMRD ASP-11 AND GLY-75.
+	Additional computationally mapped references.

Cross-references

Sequence databases
EMBL GenBank DDBJ	AF092130 mRNA. Translation: AAD40372.1. AF087850 mRNA. Translation: AAP97161.1. CH471062 Genomic DNA. Translation: EAW62249.1. CH471062 Genomic DNA. Translation: EAW62250.1. BC002847 mRNA. Translation: AAH02847.1. BC093034 mRNA. Translation: AAH93034.1.
IPI	IPI00002149.
RefSeq	NP_001028675.1. NM_001033503.2. NP_057187.1. NM_016103.3.
UniGene	Hs.432984.
3D structure databases
ProteinModelPortal	Q9Y6B6.
ModBase	Search...
Protein-protein interaction databases
IntAct	Q9Y6B6. 1 interaction.
STRING	9606.ENSP00000282606.
PTM databases
PhosphoSite	Q9Y6B6.
Polymorphism databases
DMDM	14285769.
Proteomic databases
PaxDb	Q9Y6B6.
PeptideAtlas	Q9Y6B6.
PRIDE	Q9Y6B6.
Protocols and materials databases
DNASU	51128.
StructuralBiologyKnowledgebase	Search...
Genome annotation databases
Ensembl	ENST00000402673; ENSP00000385432; ENSG00000152700. ENST00000439578; ENSP00000404997; ENSG00000152700.
GeneID	51128.
KEGG	hsa:51128.
UCSC	uc003kzq.3. human.
Organism-specific databases
CTD	51128.
GeneCards	GC05M133971.
HGNC	HGNC:10535. SAR1B.
HPA	HPA006923.
MIM	246700. phenotype. 607690. gene.
neXtProt	NX_Q9Y6B6.
Orphanet	71. Chylomicron retention disease.
PharmGKB	PA34943.
GenAtlas	Search...
Phylogenomic databases
eggNOG	COG1100.
HOGENOM	HOG000163690.
HOVERGEN	HBG104997.
InParanoid	Q9Y6B6.
KO	K07953.
OMA	SKEELDX.
OrthoDB	EOG4SJ5FT.
PhylomeDB	Q9Y6B6.
Enzyme and pathway databases
Reactome	REACT_111217. Metabolism. REACT_11123. Membrane Trafficking. REACT_17015. Metabolism of proteins. REACT_6900. Immune System.
Gene expression databases
ArrayExpress	Q9Y6B6.
Bgee	Q9Y6B6.
CleanEx	HS_SAR1B.
Genevestigator	Q9Y6B6.
GermOnline	ENSG00000152700. Homo sapiens.
Family and domain databases
InterPro	IPR005225. Small_GTP-bd_dom. IPR006689. Small_GTPase_ARF/SAR. IPR006687. Small_GTPase_SAR1. [Graphical view]
PANTHER	PTHR11711:SF12. PTHR11711:SF12. 1 hit.
Pfam	PF00025. Arf. 1 hit. [Graphical view]
PRINTS	PR00328. SAR1GTPBP.
SMART	SM00178. SAR. 1 hit. [Graphical view]
TIGRFAMs	TIGR00231. small_GTP. 1 hit.
PROSITE	PS51422. SAR1. 1 hit. [Graphical view]
ProtoNet	Search...
Other
GenomeRNAi	51128.
NextBio	53943.
SOURCE	Search...

Entry information

Entry name

SAR1B_HUMAN

Accession

Primary (citable) accession number: Q9Y6B6
Secondary accession number(s): D3DQA4, Q567T4

Entry history

Integrated into UniProtKB/Swiss-Prot:	June 1, 2001
Last sequence update:	November 1, 1999
Last modified:	May 1, 2013
This is version 122 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.