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Cho, Moo Je
Ulsan National Institute of Science and Technology
Research Interests
  • Calcium Signaling
  • Calmodulin
  • Plant Defense Mechanism


Biochemical characteristics of a rice (Oryza sativa L, IR36) G-protein alpha-subunit expressed in Escherichia coli

DC Field Value Language Seo, HS ko Choi, CH ko Lee, SY ko Cho, Moo Je ko Bahk, JD ko 2014-09-23T07:01:58Z - 2014-09-22 ko 1997-05 ko
dc.identifier.citation BIOCHEMICAL JOURNAL, v.324, pp.273 - 281 ko
dc.identifier.issn 0264-6021 ko
dc.identifier.uri -
dc.description.abstract A cDNA encoding the alpha-subunit of the heterotrimeric G-protein in rice (RGA1) was overexpressed in Escherichia coli and then isolated by Ni2+-nitrilotriacetic acid affinity chromatography. The molecular mass of RGA1 bearing a His tag was approx. 49 kDa. Immunoblot analysis using anti-RGA1 revealed that the RGA1 protein is most abundant in seedling leaves and least abundant in mature roots. It exists at particularly high levels in the immature embryo after pellicle extrusion. In addition, the RGA1 antiserum exhibited a difference in binding affinity for G alpha proteins from monocots (maize and rice) and dicots (Arabidopsis, pea, soya bean and tomato); whereas it cross-reacted with G alpha proteins of monocots, it did not with those of dicot plants. When bound to guanosine 5'-(gamma-thio)triphosphate (GTP[S]), the RGA1 protein was partially protected from tryptic proteolysis. In the presence of GTP[S], trypsin cleaved the RGA1 protein into four fragments 24, 14, 11 and 5 kDa in size. When RGA1 was bound to GDP, only the 5 kDa polypeptide was seen on SDS/PAGE after trypsin digestion. Photoaffinity labelling with [alpha-P-32]GTP and a GTP[S]-binding assay revealed that RGA1 incorporated P-32 and showed specific binding to a guanine nucleotide. Guanidine binding of RGA1 was affected by the concentration of MgCl2 (maximum at 2 mM). The rate of guanine nucleotide binding of RGA1 (k(on,GTP(S))=0.0141+/-0.0014 min(-1)) and, at steady state, the k(cat) value for GTP hydrolysis (0.0075+/-0.0001 min(-1)) were very low even at 2 mM MgCl2. The binding affinity for the nucleotides examined was in the order GTP[S] greater than or equal to GTP > GDP > CTP > ATP greater than or equal to dTTP. ko
dc.description.statementofresponsibility close -
dc.language 영어 ko
dc.publisher PORTLAND PRESS LTD ko
dc.title Biochemical characteristics of a rice (Oryza sativa L, IR36) G-protein alpha-subunit expressed in Escherichia coli ko
dc.type ARTICLE ko
dc.identifier.scopusid 2-s2.0-0030916792 ko
dc.identifier.wosid A1997XA79400035 ko
dc.type.rims ART ko
dc.description.wostc 20 *
dc.description.scopustc 20 * 2015-05-06 * 2014-09-30 *
dc.identifier.url ko
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