SAR1B secretion associated Ras related GTPase 1B [Homo sapiens (human)] - Gene

Summary

Official Symbol: SAR1Bprovided by HGNC
Official Full Name: secretion associated Ras related GTPase 1Bprovided by HGNC
Primary source: HGNC:HGNC:10535
See related: Ensembl:ENSG00000152700 MIM:607690
Gene type: protein coding
RefSeq status: REVIEWED
Organism: Homo sapiens
Lineage: Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi; Mammalia; Eutheria; Euarchontoglires; Primates; Haplorrhini; Catarrhini; Hominidae; Homo
Also known as: ANDD; CMRD; GTBPB; SARA2
Summary: The protein encoded by this gene is a small GTPase that acts as a homodimer. The encoded protein is activated by the guanine nucleotide exchange factor PREB and is involved in protein transport from the endoplasmic reticulum to the Golgi. This protein is part of the COPII coat complex. Defects in this gene are a cause of chylomicron retention disease (CMRD), also known as Anderson disease (ANDD). Two transcript variants encoding the same protein have been found for this gene. [provided by RefSeq, Mar 2010]
Expression: Ubiquitous expression in liver (RPKM 17.3), small intestine (RPKM 16.1) and 25 other tissues See more
Orthologs: mouse all
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Genomic context

Location:: 5q31.1

Exon count:: 8

Annotation release	Status	Assembly	Chr	Location
109.20210514	current	GRCh38.p13 (GCF_000001405.39)	5	NC_000005.10 (134601149..134632828, complement)
105.20201022	previous assembly	GRCh37.p13 (GCF_000001405.25)	5	NC_000005.9 (133936839..133968518, complement)

Chromosome 5 - NC_000005.10 Genomic Context describing neighboring genes

Genomic regions, transcripts, and products

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Genomic Sequence:

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Expression

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See details

Project title: HPA RNA-seq normal tissues
Description: RNA-seq was performed of tissue samples from 95 human individuals representing 27 different tissues in order to determine tissue-specificity of all protein-coding genes
BioProject: PRJEB4337
Publication: PMID 24309898
Analysis date: Wed Apr 4 07:08:55 2018

Bibliography

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GeneRIFs: Gene References Into Functions

What's a GeneRIF?

Small sequence variations between two mammalian paralogs of the small GTPase SAR1 underlie functional differences in coat protein complex II assembly.
Title: Small sequence variations between two mammalian paralogs of the small GTPase SAR1 underlie functional differences in coat protein complex II assembly.
SAR1B GTPase is necessary to protect intestinal cells from disorders of lipid homeostasis, oxidative stress, and inflammation
Title: SAR1B GTPase is necessary to protect intestinal cells from disorders of lipid homeostasis, oxidative stress, and inflammation.
Chylomicron retention disease is an autosomal recessive disorder, in which intestinal fat malabsorption is the main cause of diverse severe manifestations due to mutations in the SAR1B. (Review)
Title: Chylomicron retention disease: genetics, biochemistry, and clinical spectrum.
Twenty-three patients were genetically confirmed as affected by primary hypobetalipoproteinemia. In this group of patients, the most prevalent mutated genes were APOB (in 17 patients, with eight novel mutations identified), SAR1B (in 3 patients, with one novel mutation identified), ANGPTL3 (in 2 patients), and MTTP (in 1 patient). The other 21 patients could not be genetically diagnosed with hypobetalipoproteinemia despit
Title: Molecular analysis of APOB, SAR1B, ANGPTL3, and MTTP in patients with primary hypocholesterolemia in a clinical laboratory setting: Evidence supporting polygenicity in mutation-negative patients.
Study data suggest that SAR1A and SAR1B are the critical regulators of trafficking of Nav1.5. Moreover, SAR1A and SAR1B interact with MOG1, and are required for MOG1-mediated cell surface expression and function of Nav1.5.
Title: Small GTPases SAR1A and SAR1B regulate the trafficking of the cardiac sodium channel Na<sub>v</sub>1.5.
Targeted next generation DNA sequencing revealed several rare heterozygous missense variants in both MTTP and APOB genes known or predicted to be deleterious, in addition to a novel heterozygous missense variant in SAR1B, which encodes the gene causing chylomicron retention disease
Title: Complex genetic architecture in severe hypobetalipoproteinemia.
Report compensatory Sar1a elevation after Sar1b gene deletion in Caco-2/15 cells prevents chylomicron collapse.
Title: Understanding Chylomicron Retention Disease Through Sar1b Gtpase Gene Disruption: Insight From Cell Culture.
SAR1B polymorphisms were associated with Alzheimer's disease (AD) risk; results were not significant after correction for multiple tests. Simultaneous screening using SAR1B rs11948613 and ApoE epsilon4 status offered a better sensitivity for AD screening.
Title: Genetic polymorphisms of lipid metabolism gene SAR1 homolog B and the risk of Alzheimer's disease and vascular dementia.
Our data also suggest that Sar1B overexpression contributes to regulation of CHOL transport and metabolism by facilitating rapid uptake and transport of CHOL.
Title: New Insights In Intestinal Sar1B GTPase Regulation and Role in Cholesterol Homeostasis.
although Sar1A antagonizes the lipoprotein secretion-promoting activity of Sar1B, both isoforms modulate the expression of genes encoding cholesterol biosynthetic enzymes and the synthesis of cholesterol de novo.
Title: The endoplasmic reticulum coat protein II transport machinery coordinates cellular lipid secretion and cholesterol biosynthesis.

Submit: New GeneRIF Correction See all GeneRIFs (17)

Phenotypes

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Find tests for this gene in the NIH Genetic Testing Registry (GTR)

Review eQTL and phenotype association data in this region using PheGenI

Associated conditions

Description	Tests
Chylomicron retention disease MedGen: C0795956 OMIM: 246700 GeneReviews: Not available	Compare labs

Variation

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See variants in ClinVar

See studies and variants in dbVar

See Variation Viewer (GRCh37.p13)

See Variation Viewer (GRCh38)

Interactions

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Products	Interactant	Other Gene	Complex	Source	Pubs	Description

General gene information

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Markers

WI-21567 (e-PCR)
- UniSTS:21764

L17688 (e-PCR)
- UniSTS:74509

RH92208 (e-PCR)
- UniSTS:85779

D10S275 (e-PCR)
- UniSTS:147992

D8S2279 (e-PCR)
- UniSTS:473907

D4S133 (e-PCR)
- UniSTS:147261

A006N32 (e-PCR)
- UniSTS:39237

GDB:314949 (e-PCR)
- UniSTS:156503

L17709 (e-PCR)
- UniSTS:42599

D10S16 (e-PCR)
- UniSTS:155756

D1S1423 (e-PCR)
- UniSTS:149619

STS-W67309 (e-PCR)
- UniSTS:72372

RH91372 (e-PCR)
- UniSTS:85943

bac51510T (e-PCR)
- UniSTS:181473

D5S1585E (e-PCR)
- UniSTS:151010

RH47180 (e-PCR)
- UniSTS:6126

Homology

Homologs of the SAR1B gene: The SAR1B gene is conserved in chimpanzee, Rhesus monkey, dog, cow, mouse, rat, chicken, zebrafish, fruit fly, mosquito, C.elegans, A.thaliana, rice, and frog.
Orthologs from Annotation Pipeline: 356 organisms have orthologs with human gene SAR1B
Orthologs

Gene Ontology Provided by GOA

Function	Evidence Code	Pubs
enables GTP binding	IEA Inferred from Electronic Annotation more info
enables GTPase activity	IBA Inferred from Biological aspect of Ancestor more info	PubMed
enables GTPase activity	TAS Traceable Author Statement more info
enables metal ion binding	IEA Inferred from Electronic Annotation more info
enables protein binding	IPI Inferred from Physical Interaction more info	PubMed

Process	Evidence Code	Pubs
involved_in antigen processing and presentation of peptide antigen via MHC class I	TAS Traceable Author Statement more info
involved_in endoplasmic reticulum to Golgi vesicle-mediated transport	IBA Inferred from Biological aspect of Ancestor more info	PubMed
involved_in intracellular protein transport	IBA Inferred from Biological aspect of Ancestor more info	PubMed
involved_in membrane organization	IBA Inferred from Biological aspect of Ancestor more info	PubMed
involved_in positive regulation of protein exit from endoplasmic reticulum	IBA Inferred from Biological aspect of Ancestor more info	PubMed
involved_in regulation of COPII vesicle coating	IBA Inferred from Biological aspect of Ancestor more info	PubMed
involved_in vesicle organization	IBA Inferred from Biological aspect of Ancestor more info	PubMed

Component	Evidence Code	Pubs
part_of COPII vesicle coat	IBA Inferred from Biological aspect of Ancestor more info	PubMed
located_in ER to Golgi transport vesicle membrane	TAS Traceable Author Statement more info
located_in Golgi cisterna membrane	IEA Inferred from Electronic Annotation more info
located_in cytosol	TAS Traceable Author Statement more info
is_active_in endoplasmic reticulum exit site	IBA Inferred from Biological aspect of Ancestor more info	PubMed
located_in endoplasmic reticulum membrane	TAS Traceable Author Statement more info

General protein information

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Preferred Names: GTP-binding protein SAR1b

Names: 2310075M17Rik; GTP-binding protein B; GTP-binding protein Sara; SAR1 homolog B; SAR1a gene homolog 2

NCBI Reference Sequences (RefSeq)

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RefSeqs maintained independently of Annotated Genomes

These reference sequences exist independently of genome builds. Explain

These reference sequences are curated independently of the genome annotation cycle, so their versions may not match the RefSeq versions in the current genome build. Identify version mismatches by comparing the version of the RefSeq in this section to the one reported in Genomic regions, transcripts, and products above.

Genomic

NG_017002.1 RefSeqGene

Range

5016..36695

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GenBank, FASTA, Sequence Viewer (Graphics)

mRNA and Protein(s)

NM_001033503.3 → NP_001028675.1 GTP-binding protein SAR1b

See identical proteins and their annotated locations for NP_001028675.1

Status: REVIEWED

Description

Transcript Variant: This variant (1) represents the longer transcript. Variants 1 and 2 both encode the same protein.

Source sequence(s)

AC106763, BC093034, CD048852

Consensus CDS

CCDS4177.1

UniProtKB/Swiss-Prot

Q9Y6B6

Related

ENSP00000404997.1, ENST00000439578.5

Conserved Domains (1) summary

cd00879
Location:3 → 197

Sar1; Sar1 is an essential component of COPII vesicle coats
NM_016103.4 → NP_057187.1 GTP-binding protein SAR1b

See identical proteins and their annotated locations for NP_057187.1

Status: REVIEWED

Description

Transcript Variant: This variant (2) differs in the 5' UTR compared to variant 1. Variants 1 and 2 both encode the same protein.

Source sequence(s)

AC106763, BC093034

Consensus CDS

CCDS4177.1

UniProtKB/Swiss-Prot

Q9Y6B6

Related

ENSP00000385432.2, ENST00000402673.7

Conserved Domains (1) summary

cd00879
Location:3 → 197

Sar1; Sar1 is an essential component of COPII vesicle coats