Submitted to: National Cotton Council Beltwide Cotton Conference
Publication Type: Abstract Only
Publication Acceptance Date: 11/10/2004
Publication Date: 1/4/2005
Citation: Asprodites, N., Kim H.J., Triplett, B.A. 2005. Cloning and characterization of three Rop/Rac G-proteins from Gossypium hirsutum. Proc. Beltwide Cotton Conf., New Orleans, LA. p. 2099. http://www.cotton.org/beltwide/proceedings/2005/pdfs/2836.pdf Interpretive Summary:
Technical Abstract: Guanine nucleotide binding proteins, G proteins, are GTPases ubiquitous amongst eukaryotes and demonstrate conservation in both structure and function. As pivotal molecular switches, G proteins are activated by the binding of GTP and inactivated when GTP is hydrolyzed to GDP. G proteins are involved in signal transduction; though, the entire pathway has yet to be fully elucidated. This research focuses on a unique classification of G proteins found exclusively in plants, Rop G proteins. Rops (Rho-related GTPase from plant) belong to a superfamily of small monomeric GTPases. Until recently, only two Rop G proteins (GhRac9 and GhRac13) have been cloned from Gossypium hirsutum (Upland cotton). Here we clone three additional full-length coding G proteins, GhRac1, GhCFBD6, and GhCFBG26 from Gossypium hirsutum. GhRac1 shows the greatest sequence similarity to the Group IV Rop family in Arabidopsis thaliana, GhCFBD6 shows the greatest sequence similarity to the Group II Rop family in Arabidopsis thaliana, and GhCFBG26 shows the greatest sequence similarity to the Group I Rop family in Arabidopsis thaliana. The functions of GhRac1, GhCFBD6, and GhCFBG26 are unknown at present. Characterization of the temporal expression patterns of these G proteins will provide clues about their potential functions. Quantitative RT-PCR analysis of the expression patterns of these genes in developing ovules and fibers will be presented.