SAR1B

SAR1 homolog B (S. cerevisiae)

PDB rendering based on 1f6b.

Available structures
PDB	1f6b, 2fa9, 2fmx

Identifiers

Symbols

SAR1B; ANDD; CMRD; GTBPB; SARA2

External IDs

OMIM: 607690 MGI: 1913647 HomoloGene: 90905 GeneCards: SAR1B Gene

Gene Ontology
Molecular function	• nucleotide binding • GTPase activity • GTP binding • metal ion binding
Cellular component	• endoplasmic reticulum • endoplasmic reticulum membrane • Golgi apparatus • cytosol • ER to Golgi transport vesicle membrane • membrane • Golgi cisterna membrane
Biological process	• GTP catabolic process • intracellular protein transport • ER to Golgi vesicle-mediated transport • cellular membrane organization • vesicle-mediated transport • protein N-linked glycosylation via asparagine • post-translational protein modification • cellular protein metabolic process • COPII vesicle coating
Sources: Amigo / QuickGO

RNA expression pattern

More reference expression data

Orthologs

Species

Human

Mouse

RefSeq (mRNA)

RefSeq (protein)

Location (UCSC)

Chr 5:
133.93 – 133.98 Mb

Chr 11:
51.58 – 51.61 Mb

PubMed search

[1]

[2]

SAR1 gene homolog B (S. cerevisiae), also known as SAR1B, is a protein which in humans is encoded by the SAR1B gene.^[1]^[2]

1 Function
2 Clinical significance
3 References
4 Further reading

Function

SAR1B belongs to the Sar1-ADP ribosylation factor family of small GTPases,^[3] which govern the intracellular trafficking of proteins in coat protein (COP)-coated vesicles.^[4]

Clinical significance

Mutations in the SAR1B gene are associated with chylomicron retention disease (also known as Anderson disease) which is an autosomal recessive disorder of severe fat malabsorption.^[5]

References

^ "Entrez Gene: SAR1B SAR1 gene homolog B (S. cerevisiae)". http://www.ncbi.nlm.nih.gov/sites/entrez?Db=gene&Cmd=ShowDetailView&TermToSearch=51128.
^ He H, Dai F, Yu L, She X, Zhao Y, Jiang J, Chen X, Zhao S (2002). "Identification and characterization of nine novel human small GTPases showing variable expressions in liver cancer tissues". Gene Expr. 10 (5–6): 231–42. PMID 12450215.
^ Takai Y, Sasaki T, Matozaki T (January 2001). "Small GTP-binding proteins". Physiol. Rev. 81 (1): 153–208. PMID 11152757.
^ Schekman R, Orci L (March 1996). "Coat proteins and vesicle budding". Science 271 (5255): 1526–33. doi:10.1126/science.271.5255.1526. PMID 8599108.
^ Jones B, Jones EL, Bonney SA, Patel HN, Mensenkamp AR, Eichenbaum-Voline S, Rudling M, Myrdal U, Annesi G, Naik S, Meadows N, Quattrone A, Islam SA, Naoumova RP, Angelin B, Infante R, Levy E, Roy CC, Freemont PS, Scott J, Shoulders CC (May 2003). "Mutations in a Sar1 GTPase of COPII vesicles are associated with lipid absorption disorders". Nat. Genet. 34 (1): 29–31. doi:10.1038/ng1145. PMID 12692552.

Jardim DL, da Cunha AF, Duarte Ada S et al. (2005). "Expression of Sara2 human gene in erythroid progenitors". J. Biochem. Mol. Biol. 38 (3): 328–33. PMID 15943909.
Gerhard DS, Wagner L, Feingold EA et al. (2004). "The status, quality, and expansion of the NIH full-length cDNA project: the Mammalian Gene Collection (MGC)". Genome Res. 14 (10B): 2121–7. doi:10.1101/gr.2596504. PMC 528928. PMID 15489334. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=528928.
Ota T, Suzuki Y, Nishikawa T et al. (2004). "Complete sequencing and characterization of 21,243 full-length human cDNAs". Nat. Genet. 36 (1): 40–5. doi:10.1038/ng1285. PMID 14702039.
Jones B, Jones EL, Bonney SA et al. (2003). "Mutations in a Sar1 GTPase of COPII vesicles are associated with lipid absorption disorders". Nat. Genet. 34 (1): 29–31. doi:10.1038/ng1145. PMID 12692552.
Strausberg RL, Feingold EA, Grouse LH et al. (2003). "Generation and initial analysis of more than 15,000 full-length human and mouse cDNA sequences". Proc. Natl. Acad. Sci. U.S.A. 99 (26): 16899–903. doi:10.1073/pnas.242603899. PMC 139241. PMID 12477932. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=139241.
Aguglia U, Annesi G, Pasquinelli G et al. (2000). "Vitamin E deficiency due to chylomicron retention disease in Marinesco-Sjögren syndrome". Ann. Neurol. 47 (2): 260–4. doi:10.1002/1531-8249(200002)47:2<260::AID-ANA21>3.0.CO;2-V. PMID 10665502.
Suzuki Y, Yoshitomo-Nakagawa K, Maruyama K et al. (1997). "Construction and characterization of a full length-enriched and a 5'-end-enriched cDNA library". Gene 200 (1–2): 149–56. doi:10.1016/S0378-1119(97)00411-3. PMID 9373149.
Maruyama K, Sugano S (1994). "Oligo-capping: a simple method to replace the cap structure of eukaryotic mRNAs with oligoribonucleotides". Gene 138 (1–2): 171–4. doi:10.1016/0378-1119(94)90802-8. PMID 8125298.

PDB gallery

1f6b: CRYSTAL STRUCTURE OF SAR1-GDP COMPLEX

2fa9: The crystal structure of Sar1[H79G]-GDP provides insight into the coat-controlled GTP hydrolysis in the disassembly of COP II

2fmx: An open conformation of switch I revealed by Sar1-GDP crystal structure at low Mg(2+)

Hydrolases: acid anhydride hydrolases (EC 3.6)

3.6.1

Pyrophosphatase (Inorganic, Thiamine) · Apyrase · Thiamine-triphosphatase

3.6.2

Adenylylsulfatase · Phosphoadenylylsulfatase

3.6.3-4: ATPase

3.6.3

Cu++ (3.6.3.4)	Menkes/ATP7A · Wilson/ATP7B

Ca+ (3.6.3.8)	SERCA (ATP2A1, ATP2A2, ATP2A3) · Plasma membrane (ATP2B1, ATP2B2, ATP2B3, ATP2B4) · SPCA (ATP2C1, ATP2C2)

Na+/K+ (3.6.3.9)	ATP1A1 · ATP1A2 · ATP1A3 · ATP1A4 · ATP1B1 · ATP1B2 · ATP1B3 · ATP1B4

H+/K+ (3.6.3.10)	ATP4A

Other P-type ATPase	ATP8B1 · ATP10A · ATP11B · ATP12A · ATP13A2 · ATP13A3 ·

3.6.4

Dynein · Kinesin · Myosin

3.6.5: GTPase

3.6.5.1: Heterotrimeric G protein	G_αs · G_αi (GNAI1, GNAI2, GNAI3) · G_αq/11 (GNAQ, GNA11) · G_α12/13 (GNA12, GNA13) · Transducin (GNAT1, GNAT2)

3.6.5.2: Small GTPase > Ras superfamily	Rho family of GTPases: Cdc42 (CDC42, TC10, TCL) • RhoUV (RhoU, RhoV) • Rac (Rac1, 2, 3, RhoG) • RhoBTB (1, 2) • RhoH • Rho (A, B, C) • Rnd (1, 2, 3) • RhoDF (RhoF, RhoD) other: Ras (HRAS, KRAS, NRAS) · Rab (RAB23, RAB27) · Arf (ARF6, SAR1B, ARL13B, ARL6) · Ran · Rheb · Rap

3.6.5.3: Protein-synthesizing GTPase	Prokaryotic (IF-2, EF-Tu, EF-G) · Eukaryotic

3.6.5.5-6: Polymerization motors	Dynamin · Tubulin

B enzm: 1.1/2/3/4/5/6/7/8/10/11/13/14/15-18, 2.1/2/3/4/5/6/7/8, 2.7.10, 2.7.11-12, 3.1/2/3/4/5/6/7, 3.1.3.48, 3.4.21/22/23/24, 4.1/2/3/4/5/6, 5.1/2/3/4/99, 6.1-3/4/5-6

Hydrolases: acid anhydride hydrolases (EC 3.6)

3.6.1

Pyrophosphatase (Inorganic, Thiamine) · Apyrase · Thiamine-triphosphatase

3.6.2

Adenylylsulfatase · Phosphoadenylylsulfatase

3.6.3-4: ATPase

3.6.3

Cu++ (3.6.3.4)	Menkes/ATP7A · Wilson/ATP7B

Ca+ (3.6.3.8)	SERCA (ATP2A1, ATP2A2, ATP2A3) · Plasma membrane (ATP2B1, ATP2B2, ATP2B3, ATP2B4) · SPCA (ATP2C1, ATP2C2)

Na+/K+ (3.6.3.9)	ATP1A1 · ATP1A2 · ATP1A3 · ATP1A4 · ATP1B1 · ATP1B2 · ATP1B3 · ATP1B4

H+/K+ (3.6.3.10)	ATP4A

Other P-type ATPase	ATP8B1 · ATP10A · ATP11B · ATP12A · ATP13A2 · ATP13A3 ·

3.6.4

Dynein · Kinesin · Myosin

3.6.5: GTPase

3.6.5.1: Heterotrimeric G protein	G_αs · G_αi (GNAI1, GNAI2, GNAI3) · G_αq/11 (GNAQ, GNA11) · G_α12/13 (GNA12, GNA13) · Transducin (GNAT1, GNAT2)

3.6.5.2: Small GTPase > Ras superfamily	Rho family of GTPases: Cdc42 (CDC42, TC10, TCL) • RhoUV (RhoU, RhoV) • Rac (Rac1, 2, 3, RhoG) • RhoBTB (1, 2) • RhoH • Rho (A, B, C) • Rnd (1, 2, 3) • RhoDF (RhoF, RhoD) other: Ras (HRAS, KRAS, NRAS) · Rab (RAB23, RAB27) · Arf (ARF6, SAR1B, ARL13B, ARL6) · Ran · Rheb · Rap

3.6.5.3: Protein-synthesizing GTPase	Prokaryotic (IF-2, EF-Tu, EF-G) · Eukaryotic

3.6.5.5-6: Polymerization motors	Dynamin · Tubulin

B enzm: 1.1/2/3/4/5/6/7/8/10/11/13/14/15-18, 2.1/2/3/4/5/6/7/8, 2.7.10, 2.7.11-12, 3.1/2/3/4/5/6/7, 3.1.3.48, 3.4.21/22/23/24, 4.1/2/3/4/5/6, 5.1/2/3/4/99, 6.1-3/4/5-6

Intracellular signaling peptides and proteins

MAP

see MAP kinase pathway

Calcium

Intracellular calcium-sensing proteins • Calcineurin • Calcium-calmodulin-dependent protein kinase

G protein

Heterotrimeric	cAMP: Heterotrimeric G protein (Gs/Gi) • Adenylate cyclase • cAMP • 3',5'-cyclic-AMP phosphodiesterase • Protein kinase A cGMP: Guanylate cyclase • cGMP • 3',5'-cyclic-GMP phosphodiesterase • Protein kinase G Beta-gamma complex G_β (GNB1, GNB2, GNB3, GNB4, GNB5) • G_γ (GNGT1, GNGT2, GNG2, GNG3, GNG4, GNG5, GNG7, GNG8, GNG10, GNG11, GNG12, GNG13, BSCL2) G protein-coupled receptor kinase • AMP-activated protein kinase

Monomeric	ARFs · Rabs · Ras (HRAS, KRAS, NRAS)

Cyclin

Cyclin-dependent kinase inhibitor protein • Cyclin-dependent kinase • Cyclin

Lipid

Phosphoinositide phospholipase C • Phospholipase c gamma

Other protein kinase

Serine/threonine: Casein kinase (1, 2) • eIF-2 kinase (EIF2AK3) • Glycogen synthase kinase (GSK1, GSK2, GSK-3, GSK3A, GSK3B) • IκB kinase (CHUK, IKK2, IKBKG) • Interleukin-1 receptor-associated kinase (IRAK1, IRAK2, IRAK3, IRAK4) • Lim kinase (LIMK1, LIMK2) • p21 activated kinases (PAK1, PAK2, PAK3, PAK4) • Rho-associated protein kinase (ROCK1, ROCK2) • Ribosomal s6 kinase (RPS6KA1)

Tyrosine: ZAP70 • Focal adhesion protein-tyrosine kinase (PTK2, PTK2B) • BTK

both: Dual-specificity kinase

Other phosphoprotein phosphatase

Serine/threonine: Protein phosphatase 2

Tyrosine: protein tyrosine phosphatase: Receptor-like protein tyrosine phosphatase • Sh2 domain-containing protein tyrosine phosphatase

both: Dual-specificity phosphatase

Apoptosis

see apoptosis signaling pathway

GTP-binding protein regulators

see GTP-binding protein regulators

Other

Activating transcription factor 6 • Signal transducing adaptor protein • I-kappa B protein • Mucin-4 • Olfactory marker protein • Phosphatidylethanolamine binding protein • EDARADD • PRKCSH

see also deficiencies of intracellular signaling peptides and proteins
B trdu: iter (nrpl/grfl/cytl/horl), csrc (lgic, enzr, gprc, igsr, intg, nrpr/grfr/cytr), itra (adap, gbpr, mapk), calc, lipd; path (hedp, wntp, tgfp+mapp, notp, jakp, fsap, hipp, tlrp)

SAR1B

Contents

Function

Clinical significance

References

Further reading