View source for SAR1A

{{infobox protein
|name=SAR1 homolog A (S. cerevisiae)
|caption=
|image=
|width=
|HGNCid=10534
|Symbol=SAR1A
|AltSymbols=SARA1
|EntrezGene=56681
|OMIM=607691
|RefSeq=
|UniProt=
|PDB=
|ECnumber=
|Chromosome=10
|Arm=q
|Band=22.1
|LocusSupplementaryData=
}}
'''SAR1A''' or '''Sar1''' is a protein involved in membrane trafficking. It is a [[GTPase|monomeric small GTPase]] found in [[COPII|COPII vesicles]]. It regulates the assembly and disassembly of COPII coats.

[[GDP]]-bound Sar1 interacts with the membrane-bound exchange factor [[Sec12]] and exchanges its bound GDP for GTP. The [[hydrophobic]] [[N-terminus]] of Sar1-GTP then locates it to the membrane, where it serves as the binding site for the [[Sec23]]/[[Sec24]] protein coat complex. After the vesicle coat is completely assembled and the vesicle is released from the donor membrane, the [[Sec23]] subunit promotes Sar1 GTPase activity, which triggers the disassembly of the COPII coat.

==See also==
*[[ADP ribosylation factor|ARF]]

==External links==

{{Vesicular transport proteins}}

[[Category:Biomolecules]]


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