Rice GDP dissociation inhibitor 3 inhibits OsMAPK2 activity through physical interaction.
GDP dissociation inhibitor (GDI) plays an essential role in regulating the state of bound nucleotides and subcellular localizations of Rab proteins. In our previous study, we showed that OsGDI3 facilitates the recycling of OsRab11 with a help of OsGAP1. In this study, we show that OsGDI3 complement the yeast sec19-1 mutant, a temperature-sensitive allele of the yeast GDI gene, suggesting that OsGDI3 is a functional ortholog of yeast GDI. To obtain further knowledge on the function of OsGDI3, candidate OsGDI3-interacting proteins were identified by yeast two-hybrid screens. OsMAPK2 is one of OsGDI3 interacting proteins from yeast two-hybrid screens and subject to further analysis. A kinase assay showed that the autophosphorylation activity of OsMAPK2 is inhibited by OsGDI3 in vitro. In addition, ectopic expressions of OsGDI3-in Arabidopsis cause reductions at the level of phosphorylated AtMPK in phosphorylation activity. Taken together, OsGDI3 functions as a negative regulator of OsMAPK2 through modulating its kinase activity.
Department of Molecular Biotechnology, Dong-A University, Busan 604-714, Republic of Korea.
Jae Bok
JB
Heo
Young Byung
YB
Yi
Jeong Dong
JD
Bahk
D020730:Guanine Nucleotide Dissociation Inhibitors / Q000235:genetics / Q000378:metabolism*; D006153:Guanosine Diphosphate / Q000378:metabolism; D006160:Guanosine Triphosphate / Q000378:metabolism; D019950:Mitogen-Activated Protein Kinase 1 / Q000037:antagonists & inhibitors / Q000378:metabolism*; D012275:Oryza / Q000378:metabolism*; D020798:Two-Hybrid System Techniques; D020691:rab GTP-Binding Proteins / Q000378:metabolism; D000099193:rab11 GTP-Binding Proteins
D020730:Guanine Nucleotide Dissociation Inhibitors; D006153:Guanosine Diphosphate; D006160:Guanosine Triphosphate; D019950:Mitogen-Activated Protein Kinase 1; D020691:rab GTP-Binding Proteins; D000099193:rab11 GTP-Binding Proteins