Proteomics Analysis of Plasma Membrane Fractions of the Root, Leaf, and Flower of Rice.

The plasma membrane regulates biological processes such as ion transport, signal transduction, endocytosis, and cell differentiation/proliferation. To understand the functional characteristics and organ specificity of plasma membranes, plasma membrane protein fractions from rice root, etiolated leaf, green leaf, developing leaf sheath, and flower were analyzed by proteomics. Among the proteins identified, 511 were commonly accumulated in the five organs, whereas 270, 132, 359, 146, and 149 proteins were specifically accumulated in the root, etiolated leaf, green leaf, developing leaf sheath, and developing flower, respectively.

Characterization of Heterotrimeric G Protein γ4 Subunit in Rice.

Heterotrimeric G proteins are the molecule switch that transmits information from external signals to intracellular target proteins in mammals and yeast cells. In higher plants, heterotrimeric G proteins regulate plant architecture. Rice harbors one canonical α subunit gene (), four extra-large GTP-binding protein genes (XLGs), one canonical β-subunit gene (), and five γ-subunit genes (tentatively designated , , ///, ////, and /) as components of the heterotrimeric G protein complex.

Identification of Heterotrimeric G Protein γ3 Subunit in Rice Plasma Membrane.

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 (), four extra-large GTP-binding protein genes (XLGs), one canonical β subunit gene ), and five γ subunit genes (tentatively named , , , , and ). encodes the canonical γ subunit; 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.