Identification of Heterotrimeric G Protein γ3 Subunit in Rice Plasma Membrane

International Journal of Molecular Sciences

Takafumi Itoh¹  Genki Chaya¹  Kotaro Miura¹  Aki Nishiyama¹  Yukimoto Iwasaki¹  Sakura Matsuta¹ 

[1] Department of Bioscience and Biotechnology, Fukui Prefectural University, 4-1-1 Kenjojima, Matsuoka, Eiheiji-Town, Fukui 910-1195, Japan;

关键词: GS3;    γ subunit;    heterotrimeric G protein;    mass spectrometric analysis;    RGG3;    rice;    western blotting;   

DOI  :  10.3390/ijms19113591

来源: DOAJ

【 摘 要 】

Heterotrimeric G proteins are important molecules for regulating plant architecture and transmitting external signals to intracellular target proteins in higher plants and mammals. The rice genome contains one canonical α subunit gene (RGA1), four extra-large GTP-binding protein genes (XLGs), one canonical β subunit gene (RGB1), and five γ subunit genes (tentatively named RGG1, RGG2, RGG3/GS3/Mi/OsGGC1, RGG4/DEP1/DN1/OsGGC3, and RGG5/OsGGC2). RGG1 encodes the canonical γ subunit; RGG2 encodes the plant-specific type of γ subunit with additional amino acid residues at the N-terminus; and the remaining three γ subunit genes encode the atypical γ subunits with cysteine abundance at the C-terminus. We aimed to identify the RGG3/GS3/Mi/OsGGC1 gene product, Gγ3, in rice tissues using the anti-Gγ3 domain antibody. We also analyzed the truncated protein, Gγ3∆Cys, in the RGG3/GS3/Mi/OsGGC1 mutant, Mi, using the anti-Gγ3 domain antibody. Based on nano-liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis, the immunoprecipitated Gγ3 candidates were confirmed to be Gγ3. Similar to α (Gα) and β subunits (Gβ), Gγ3 was enriched in the plasma membrane fraction, and accumulated in the flower tissues. As RGG3/GS3/Mi/OsGGC1 mutants show the characteristic phenotype in flowers and consequently in seeds, the tissues that accumulated Gγ3 corresponded to the abnormal tissues observed in RGG3/GS3/Mi/OsGGC1 mutants.

【 授权许可】

Unknown