OsSar1a

• Symbol: OsSar1a
• MSU: LOC_Os01g23620
• RAPdb: Os01g0338000

• Small GTPase Sar1 is crucial for proglutelin and alpha-globulin export from the endoplasmic reticulum in rice endosperm, 2013, J Exp Bot.
• A deleterious Sar1c variant in rice inhibits export of seed storage proteins from the endoplasmic reticulum., 2022, Plant Mol Biol.

Genbank accession number

• However, simultaneous knockdown of OsSar1a/b/c resulted in floury and shrunken seeds, with an increased level of glutelin precursor and decreased level of the mature alpha- and beta-subunit
• To reveal the route by which glutelin and alpha-globulin exit the ER, four putative Sar1 genes (OsSar1a/b/c/d) were cloned from rice, and transgenic rice were generated with Sar1 overexpressed or suppressed by RNA interference (RNAi) specifically in the endosperm under the control of the rice glutelin promoter
• OsSar1abc RNAi endosperm generated numerous, spherical, novel protein bodies with highly electron-dense matrixes containing both glutelin and alpha-globulin
• These results indicated that OsSar1a/b/c play a crucial role in storage proteins exiting from the ER, with functional redundancy in rice endosperm, and glutelin and alpha-globulin transported together from the ER to the Golgi apparatus by a pathway mediated by coat protein complex II