A cold-induced thioredoxin h of rice, OsTrx23, negatively regulates kinase activities of OsMPK3 and OsMPK6 in vitro

Cytosolic thioredoxins are small conserved proteins that are involved in cellular redox regulation. Here, we report that a major and cold-induced thioredoxin h of rice, OsTrx23, has an inhibitory activity on stress-activated mitogen-activated protein kinases (MAPKs), OsMPK3 and OsMPK6 in vitro. This inhibition effects were redox-dependent and did not involve stable physical interaction. The data suggested a novel mechanism for redox regulation of MAPKs in plants. Structured summary: MINT-7234362: MPK3 ( uniprotkb: Q10N20) phosphorylates (MI: 0217) MBP ( uniprotkb: P02687) by protein kinase assay ( MI: 0424) MINT-7234435: MPK6 ( uniprotkb: Q336X9) phosphorylates ( MI: 0217) MBP ( uniprotkb: P02687) by protein kinase assay ( MI: 0424) (C) 2009 Federation of European Biochemical Societies. Published by Elsevier B. V. All rights reserved.