Stress induced β subunit of heterotrimeric G-proteins from Pisum sativum interacts with mitogen activated protein kinase.

We here report in Pisum sativum system a novel protein-protein interaction of β-subunit of heterotrimeric G-proteins (PsGβ) with a Mitogen activated protein kinase (PsMPK3) during cDNA library screening by yeast-two-hybrid assay. The transcript of these two genes also showed co-regulation under abscisic acid (ABA) and methyl jasmonate (MeJA) treatments. The protein-protein interaction was further validated by performing one-to-one interaction and β-galactosidase assay in yeast system. β-subunit of G-proteins from a heterologous system Oryzae sativa also showed interaction with PsMPK3. The interaction between PsGβ and PsMPK3 was further confirmed by in vitro protein-protein interaction. This suggested that MPK3 function as effector molecule for Gβ, which may helps in the regulation of stomatal functioning. These findings also provide an evidence for a possible cross-talk between MPK3 and G-protein-mediated signaling pathways in plants.