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Protein

GTP-binding protein SAR1b

Gene

SAR1B

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

Functioni

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.

Sites

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Metal bindingi34 – 341MagnesiumBy similarity
Metal bindingi75 – 751MagnesiumBy similarity

Regions

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Nucleotide bindingi32 – 398GTPBy similarity
Nucleotide bindingi75 – 784GTPBy similarity
Nucleotide bindingi134 – 1374GTPBy similarity

GO - Molecular functioni

  1. GTPase activity Source: Reactome
  2. GTP binding Source: UniProtKB-KW
  3. metal ion binding Source: UniProtKB-KW

GO - Biological processi

  1. antigen processing and presentation of exogenous peptide antigen via MHC class II Source: Reactome
  2. antigen processing and presentation of peptide antigen via MHC class I Source: Reactome
  3. cellular protein metabolic process Source: Reactome
  4. COPII vesicle coating Source: Reactome
  5. ER to Golgi vesicle-mediated transport Source: Reactome
  6. intracellular protein transport Source: InterPro
  7. membrane organization Source: Reactome
  8. post-translational protein modification Source: Reactome
  9. protein N-linked glycosylation via asparagine Source: Reactome
  10. small molecule metabolic process Source: Reactome
Complete GO annotation...

Keywords - Biological processi

ER-Golgi transport, Protein transport, Transport

Keywords - Ligandi

GTP-binding, Magnesium, Metal-binding, Nucleotide-binding

Enzyme and pathway databases

ReactomeiREACT_121399. MHC class II antigen presentation.
REACT_12507. COPII (Coat Protein 2) Mediated Vesicle Transport.
REACT_147797. Regulation of cholesterol biosynthesis by SREBP (SREBF).
REACT_75795. Antigen Presentation: Folding, assembly and peptide loading of class I MHC.

Names & Taxonomyi

Protein namesi
Recommended name:
GTP-binding protein SAR1b
Alternative name(s):
GTP-binding protein B
Short name:
GTBPB
Gene namesi
Name:SAR1B
Synonyms:SARA2, SARB
OrganismiHomo sapiens (Human)
Taxonomic identifieri9606 [NCBI]
Taxonomic lineageiEukaryotaMetazoaChordataCraniataVertebrataEuteleostomiMammaliaEutheriaEuarchontogliresPrimatesHaplorrhiniCatarrhiniHominidaeHomo
ProteomesiUP000005640: Chromosome 5

Organism-specific databases

HGNCiHGNC:10535. SAR1B.

Subcellular locationi

Endoplasmic reticulum membrane By similarity; Peripheral membrane protein By similarity. Golgi apparatusGolgi stack membrane By similarity; Peripheral membrane protein By similarity
Note: Associated with the endoplasmic reticulum and Golgi stacks, in particular in the juxta-nuclear Golgi region.By similarity

GO - Cellular componenti

  1. cytosol Source: Reactome
  2. endoplasmic reticulum membrane Source: Reactome
  3. ER to Golgi transport vesicle membrane Source: Reactome
  4. Golgi cisterna membrane Source: UniProtKB-SubCell
Complete GO annotation...

Keywords - Cellular componenti

Endoplasmic reticulum, Golgi apparatus, Membrane

Pathology & Biotechi

Involvement in diseasei

Chylomicron retention disease3 Publications

The disease is caused by mutations affecting the gene represented in this entry.

Disease descriptionAn 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.

See also OMIM:246700
Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Natural varianti11 – 111G → D in CMRD. 1 Publication
VAR_059051
Natural varianti37 – 371G → R in CMRD; loss of GDP/GTP-binding. 1 Publication
VAR_016806
Natural varianti75 – 751D → G in CMRD. 1 Publication
VAR_059052
Natural varianti137 – 1371D → N in CMRD; reduced affinity for GDP/GTP. 1 Publication
Corresponds to variant rs28942109 [ dbSNP | Ensembl ].
VAR_016807
Natural varianti179 – 1791S → R in CMRD; loss of GDP/GTP-binding. 1 Publication
Corresponds to variant rs28942110 [ dbSNP | Ensembl ].
VAR_016808

Keywords - Diseasei

Disease mutation

Organism-specific databases

MIMi246700. phenotype.
Orphaneti71. Chylomicron retention disease.
PharmGKBiPA34943.

PTM / Processingi

Molecule processing

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Chaini1 – 198198GTP-binding protein SAR1bPRO_0000206261Add
BLAST

Amino acid modifications

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Modified residuei164 – 1641Phosphoserine1 Publication

Keywords - PTMi

Phosphoprotein

Proteomic databases

MaxQBiQ9Y6B6.
PaxDbiQ9Y6B6.
PeptideAtlasiQ9Y6B6.
PRIDEiQ9Y6B6.

PTM databases

PhosphoSiteiQ9Y6B6.

Expressioni

Tissue specificityi

Expressed in many tissues including small intestine, liver, muscle and brain.

Gene expression databases

BgeeiQ9Y6B6.
CleanExiHS_SAR1B.
ExpressionAtlasiQ9Y6B6. baseline and differential.
GenevestigatoriQ9Y6B6.

Organism-specific databases

HPAiHPA006923.
HPA048368.

Interactioni

Subunit structurei

Homodimer. Binds PREB. Part of the COPII coat complex. Binds to the cytoplasmic tails of target proteins in the endoplasmic reticulum (By similarity).By similarity

Protein-protein interaction databases

BioGridi119315. 13 interactions.
IntActiQ9Y6B6. 1 interaction.
STRINGi9606.ENSP00000282606.

Structurei

3D structure databases

ProteinModelPortaliQ9Y6B6.
SMRiQ9Y6B6. Positions 13-198.
ModBaseiSearch...
MobiDBiSearch...

Family & Domainsi

Sequence similaritiesi

Belongs to the small GTPase superfamily. SAR1 family.Curated

Phylogenomic databases

eggNOGiCOG1100.
GeneTreeiENSGT00550000074696.
HOGENOMiHOG000163690.
HOVERGENiHBG104997.
InParanoidiQ9Y6B6.
KOiK07953.
OMAiMKELNTR.
OrthoDBiEOG7W1550.
PhylomeDBiQ9Y6B6.
TreeFamiTF312890.

Family and domain databases

Gene3Di3.40.50.300. 1 hit.
InterProiIPR027417. P-loop_NTPase.
IPR005225. Small_GTP-bd_dom.
IPR006689. Small_GTPase_ARF/SAR.
IPR006687. Small_GTPase_SAR1.
[Graphical view]
PfamiPF00025. Arf. 1 hit.
[Graphical view]
PRINTSiPR00328. SAR1GTPBP.
SMARTiSM00178. SAR. 1 hit.
[Graphical view]
SUPFAMiSSF52540. SSF52540. 1 hit.
TIGRFAMsiTIGR00231. small_GTP. 1 hit.
PROSITEiPS51422. SAR1. 1 hit.
[Graphical view]

Sequencei

Sequence statusi: Complete.

Q9Y6B6-1 [UniParc]FASTAAdd to basket

« Hide

        10         20         30         40         50
MSFIFDWIYS GFSSVLQFLG LYKKTGKLVF LGLDNAGKTT LLHMLKDDRL
60 70 80 90 100
GQHVPTLHPT SEELTIAGMT FTTFDLGGHV QARRVWKNYL PAINGIVFLV
110 120 130 140 150
DCADHERLLE SKEELDSLMT DETIANVPIL ILGNKIDRPE AISEERLREM
160 170 180 190
FGLYGQTTGK GSISLKELNA RPLEVFMCSV LKRQGYGEGF RWMAQYID
Length:198
Mass (Da):22,410
Last modified:November 1, 1999 - v1
Checksum:i3F567683D7F509E6
GO

Natural variant

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Natural varianti11 – 111G → D in CMRD. 1 Publication
VAR_059051
Natural varianti37 – 371G → R in CMRD; loss of GDP/GTP-binding. 1 Publication
VAR_016806
Natural varianti75 – 751D → G in CMRD. 1 Publication
VAR_059052
Natural varianti137 – 1371D → N in CMRD; reduced affinity for GDP/GTP. 1 Publication
Corresponds to variant rs28942109 [ dbSNP | Ensembl ].
VAR_016807
Natural varianti179 – 1791S → R in CMRD; loss of GDP/GTP-binding. 1 Publication
Corresponds to variant rs28942110 [ dbSNP | Ensembl ].
VAR_016808

Sequence databases

Select the link destinations:
EMBLi
GenBanki
DDBJi
Links Updated
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.
CCDSiCCDS4177.1.
RefSeqiNP_001028675.1. NM_001033503.2.
NP_057187.1. NM_016103.3.
XP_006714704.1. XM_006714641.1.
UniGeneiHs.432984.

Genome annotation databases

EnsembliENST00000402673; ENSP00000385432; ENSG00000152700.
ENST00000439578; ENSP00000404997; ENSG00000152700.
GeneIDi51128.
KEGGihsa:51128.
UCSCiuc003kzq.3. human.

Polymorphism databases

DMDMi14285769.

Cross-referencesi

Sequence databases

Select the link destinations:
EMBLi
GenBanki
DDBJi
Links Updated
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.
CCDSiCCDS4177.1.
RefSeqiNP_001028675.1. NM_001033503.2.
NP_057187.1. NM_016103.3.
XP_006714704.1. XM_006714641.1.
UniGeneiHs.432984.

3D structure databases

ProteinModelPortaliQ9Y6B6.
SMRiQ9Y6B6. Positions 13-198.
ModBaseiSearch...
MobiDBiSearch...

Protein-protein interaction databases

BioGridi119315. 13 interactions.
IntActiQ9Y6B6. 1 interaction.
STRINGi9606.ENSP00000282606.

PTM databases

PhosphoSiteiQ9Y6B6.

Polymorphism databases

DMDMi14285769.

Proteomic databases

MaxQBiQ9Y6B6.
PaxDbiQ9Y6B6.
PeptideAtlasiQ9Y6B6.
PRIDEiQ9Y6B6.

Protocols and materials databases

DNASUi51128.
Structural Biology KnowledgebaseSearch...

Genome annotation databases

EnsembliENST00000402673; ENSP00000385432; ENSG00000152700.
ENST00000439578; ENSP00000404997; ENSG00000152700.
GeneIDi51128.
KEGGihsa:51128.
UCSCiuc003kzq.3. human.

Organism-specific databases

CTDi51128.
GeneCardsiGC05M133936.
HGNCiHGNC:10535. SAR1B.
HPAiHPA006923.
HPA048368.
MIMi246700. phenotype.
607690. gene.
neXtProtiNX_Q9Y6B6.
Orphaneti71. Chylomicron retention disease.
PharmGKBiPA34943.
GenAtlasiSearch...

Phylogenomic databases

eggNOGiCOG1100.
GeneTreeiENSGT00550000074696.
HOGENOMiHOG000163690.
HOVERGENiHBG104997.
InParanoidiQ9Y6B6.
KOiK07953.
OMAiMKELNTR.
OrthoDBiEOG7W1550.
PhylomeDBiQ9Y6B6.
TreeFamiTF312890.

Enzyme and pathway databases

ReactomeiREACT_121399. MHC class II antigen presentation.
REACT_12507. COPII (Coat Protein 2) Mediated Vesicle Transport.
REACT_147797. Regulation of cholesterol biosynthesis by SREBP (SREBF).
REACT_75795. Antigen Presentation: Folding, assembly and peptide loading of class I MHC.

Miscellaneous databases

ChiTaRSiSAR1B. human.
GeneWikiiSAR1B.
GenomeRNAii51128.
NextBioi53943.
PROiQ9Y6B6.
SOURCEiSearch...

Gene expression databases

BgeeiQ9Y6B6.
CleanExiHS_SAR1B.
ExpressionAtlasiQ9Y6B6. baseline and differential.
GenevestigatoriQ9Y6B6.

Family and domain databases

Gene3Di3.40.50.300. 1 hit.
InterProiIPR027417. P-loop_NTPase.
IPR005225. Small_GTP-bd_dom.
IPR006689. Small_GTPase_ARF/SAR.
IPR006687. Small_GTPase_SAR1.
[Graphical view]
PfamiPF00025. Arf. 1 hit.
[Graphical view]
PRINTSiPR00328. SAR1GTPBP.
SMARTiSM00178. SAR. 1 hit.
[Graphical view]
SUPFAMiSSF52540. SSF52540. 1 hit.
TIGRFAMsiTIGR00231. small_GTP. 1 hit.
PROSITEiPS51422. SAR1. 1 hit.
[Graphical view]
ProtoNetiSearch...

Publicationsi

« Hide 'large scale' publications
  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. 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. Cited for: IDENTIFICATION BY MASS SPECTROMETRY [LARGE SCALE ANALYSIS].
  6. "An enzyme assisted RP-RPLC approach for in-depth analysis of human liver phosphoproteome."
    Bian Y., Song C., Cheng K., Dong M., Wang F., Huang J., Sun D., Wang L., Ye M., Zou H.
    J. Proteomics 96:253-262(2014) [PubMed] [Europe PMC] [Abstract]
    Cited for: PHOSPHORYLATION [LARGE SCALE ANALYSIS] AT SER-164, IDENTIFICATION BY MASS SPECTROMETRY [LARGE SCALE ANALYSIS].
    Tissue: Liver.
  7. Cited for: VARIANTS CMRD ARG-37; ASN-137 AND ARG-179.
  8. "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.
  9. Cited for: VARIANTS CMRD ASP-11 AND GLY-75.

Entry informationi

Entry nameiSAR1B_HUMAN
AccessioniPrimary (citable) accession number: Q9Y6B6
Secondary accession number(s): D3DQA4, Q567T4
Entry historyi
Integrated into UniProtKB/Swiss-Prot: June 1, 2001
Last sequence update: November 1, 1999
Last modified: March 4, 2015
This is version 140 of the entry and version 1 of the sequence. [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

Keywords - Technical termi

Complete proteome, Reference proteome

Documents

  1. Human chromosome 5
    Human chromosome 5: 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. SIMILARITY comments
    Index of protein domains and families

External Data

Dasty 3

Similar proteinsi

Links to similar proteins from the UniProt Reference Clusters (UniRef) at 100%, 90% and 50% sequence identity:
100%UniRef100 combines identical sequences and sub-fragments with 11 or more residues from any organism into Uniref entry.
90%UniRef90 is built by clustering UniRef100 sequences that have at least 90% sequence identity to, and 80% overlap with, the longest sequence (a.k.a seed sequence).
50%UniRef50 is built by clustering UniRef90 seed sequences that have at least 50% sequence identity to, and 80% overlap with, the longest sequence in the cluster.