title: Arabidopsis nucleoside diphosphate kinase-2 as a plant GTPase activating protein.
abstract: Nucleoside diphosphate kinase (NDPK) is involved in multiple signaling pathways in mammalian systems, including G-protein signaling. Arabidopsis NDPK2, like its mammalian counterparts, is multifunctional despite its initial discovery phytochrome-interacting protein. This similarity raises the possibility that NDPK2 may play a role in G-protein signaling in plants. In the present study, we explore the potential relationship between NDPK2 and the small G proteins, Pra2 and Pra3, as well as the heterotrimeric G protein, GPA1. We report a physical interaction between NDPK2 and these small G proteins, and demonstrate that NDPK2 can stimulate their GTPase activities. Our results suggest that NDPK2 acts as a GTPase-activating protein for small G proteins in plants. We propose that NDPK2 might be a missing link between the phytochromemediated light signaling and G protein-mediated signaling.
authors.affiliation: Department of Chemistry, University of Nebraska-Lincoln, Lincoln, NE 68588, USA.
authors.forename: Yu
authors.initials: Y
authors.lastname: Shen
authors.forename: Yun-Jeong
authors.initials: YJ
authors.lastname: Han
authors.forename: Jeong-Il
authors.initials: JI
authors.lastname: Kim
authors.forename: Pill-Soon
authors.initials: PS
authors.lastname: Song
mesh_terms: D017360:Arabidopsis / Q000201:enzymology*; D029681:Arabidopsis Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D020690:GTPase-Activating Proteins / Q000235:genetics / Q000378:metabolism*; D016244:Guanosine 5'-O-(3-Thiotriphosphate) / Q000378:metabolism; D007527:Isoenzymes / Q000235:genetics / Q000378:metabolism*; D009701:Nucleoside-Diphosphate Kinase / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D011487:Protein Conformation; D020691:rab GTP-Binding Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: D029681:Arabidopsis Proteins; D020690:GTPase-Activating Proteins; D007527:Isoenzymes; D016244:Guanosine 5'-O-(3-Thiotriphosphate); D009701:Nucleoside-Diphosphate Kinase; D020691:rab GTP-Binding Proteins