title: PKS5, a SNF1-related kinase, interacts with and phosphorylates NPR1, and modulates expression of WRKY38 and WRKY62.
abstract: NPR1 (Nonexpressor of Pathogenesis-Related gene 1) is a major co-activator of plant defense. Phosphorylations of NPR1 play important roles in fine-tuning its activity, however a kinase corresponding to such modification remains uncharacterized. Here, we report that NPR1 interacts with PKS5 (SOS2-like Protein Kinase 5). The AKR (AnKyrin Repeats) motif of NPR1 is required for this interaction. PKS5 phosphorylates NPR1 at the C-terminal region. Expression of PKS5 is induced quickly by Pseudomonas syringae pv. tomato DC3000. Expression level of two NPR1 target genes, WRKY38 and WRKY62, is reduced and/or delayed in pks5 mutants. Moreover, the expression of WRKY38 and WRKY62 displays a similar pattern in npr1-1pks5-1 double mutant comparing to that in npr1-1. Our results suggest that PKS5 functions at the upstream of NPR1 and might mediate expression of WRKY38 and WRKY62 possibly by interacting with and phosphorylating NPR1.
authors.affiliation: College of Life Sciences, Peking University, Beijing, China. xiechanggen@nibs.ac.cn
authors.forename: Changgen
authors.initials: C
authors.lastname: Xie
authors.forename: Xiaona
authors.initials: X
authors.lastname: Zhou
authors.forename: Xingwang
authors.initials: X
authors.lastname: Deng
authors.forename: Yan
authors.initials: Y
authors.lastname: Guo
mesh_terms: D000818:Animals; D017089:Ankyrin Repeat; D017360:Arabidopsis / Q000235:genetics* / Q000378:metabolism* / Q000382:microbiology; D029681:Arabidopsis Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant; D055786:Gene Knockout Techniques; D010766:Phosphorylation; D011485:Protein Binding; D017346:Protein Serine-Threonine Kinases / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D044224:Pseudomonas syringae / Q000502:physiology; D014157:Transcription Factors / Q000235:genetics*; D015533:Transcriptional Activation; D020798:Two-Hybrid System Techniques
chemical_list: D029681:Arabidopsis Proteins; D017346:Protein Serine-Threonine Kinases; D014157:Transcription Factors; C542190:At5g22570 protein, Arabidopsis; C105496:NPR1 protein, Arabidopsis; C523309:WRKY62 protein, Arabidopsis; C523537:SIP4 protein, Arabidopsis