Sar1 | Secretion-associated and Ras-related protein 1

For immunogold experiments plant tissue has been fixed with GA in PFA/PIPES. LR White resin has been used. Tested species were: Triticum aestivum, Panicum miliaceum, Panicum maximum, Echinochloa crus-galli Eragrostis neomexicana, Digitaria sanguinalis. Publication in preparation.,Immunolocalization method with Sar1 antibodies is described in: Yao-dong Yang (2005).  Dynamics of COPII vesicles and the Golgi apparatus in cultured Nicotiana tabacum BY-2 cells provides evidence for transient association of Golgi stacks with endoplasmic reticulum exit sites. Plant Cell. 2005 May;17(5):1513-31. Epub 2005 Apr 1.

Sar1 belongs to a small GTP superfamily with GTP-linked activity. This protein is involved in protein transport within cells. There are two different types of non-clathrin-coated vesicles responsible for transport between the ER and the Golgi apparatus. The coat protein complex of Arf1 and Sar1p, including the membrane-associated GTP binding proteins COPI and COPII, is required for the formation of COPI-coated vesicles. Sar1p is a cytoplasmic protein. It is temporarily recruited to the membrane of the endoplasmic reticulum.