title: Biochemical character of the purified OsRAA1, a novel rice protein with GTP-binding activity, and its expression pattern in Oryza sativa.
abstract: OsRAA1, as previously reported, is a novel conserved protein in plants and plays an important role in rice root development. Overexpression of OsRAA1 results in reduced growth of primary roots and an increased number of adventitious roots. The biochemical functions and expression patterns of OsRAA1, however, remain poorly understood. To obtain purified OsRAA1 for biochemical analysis, the coding region was amplified by RT-PCR and expressed as a fusion protein with glutathione S-transferase in Escherichia coli. The antibodies to OsRAA1 were prepared by a synthetic 15-residue peptide (YYEDPSLFQFHKRGS) cross-linked with bovine serum albumin. Results of isotope labeling experiments suggested that OsRAA1 had binding activities with [alpha-32P]-GTP. The immunoprecipitation data showed that OsRAA1 had tissue-specific expression in roots and spikes rather than young shoots and leaves, which was consistent with its transcriptional expression. Our results indicate that OsRAA1 GTP-binding activity may contribute to the regulation mechanism of root development mediated by OsRAA1.
authors.affiliation: Key Laboratory of Photosynthesis and Environmental Molecular Physiology, Institute of Botany, The Chinese Academy of Sciences, Beijing 100093, China.
authors.forename: Ye
authors.initials: Y
authors.lastname: Han
authors.forename: Xin
authors.initials: X
authors.lastname: Wang
authors.forename: Jiafu
authors.initials: J
authors.lastname: Jiang
authors.forename: Yunyuan
authors.initials: Y
authors.lastname: Xu
authors.forename: Zhihong
authors.initials: Z
authors.lastname: Xu
authors.forename: Kang
authors.initials: K
authors.lastname: Chong
mesh_terms: D000818:Animals; D000906:Antibodies; D019204:GTP-Binding Proteins / Q000096:biosynthesis / Q000378:metabolism*; D007120:Immunochemistry; D012275:Oryza / Q000378:metabolism*; D018515:Plant Leaves / Q000378:metabolism; D010940:Plant Proteins / Q000096:biosynthesis / Q000378:metabolism*; D018517:Plant Roots / Q000378:metabolism; D018520:Plant Shoots / Q000378:metabolism; D011817:Rabbits
chemical_list: D000906:Antibodies; D010940:Plant Proteins; D019204:GTP-Binding Proteins