Dephosphorylated mutations affect the protein-protein interactions of ERF in Populus simonii x P. nigra

摘要

Phosphorylation is a common type of post-translational modification (PTM). It plays a vital role in many cellular processes. The reversible phosphorylation and dephosphorylation affect protein structures and proteinprotein interactions. Previously, we obtained five proteins that interact with ethylene-responsive factor (ERF) from the cDNA library of Populus simonii x Populus nigra . To further investigate the effect of dephosphorylation of PsnERF on its protein binding ability, we generated different phosphorylation states of PsnERF and demonstrated their protein binding capacity by the yeast two-hybrid assay (Y2H). The secondary structures and 3D structures of PsnERF, ERFm, TrunERF, and psnerf 197/198/202a were predicted by homology modeling. The Y2H assay indicated that the deletion of serine-rich regions does not affect the interactions, while dephosphorylated mutations blocked the interactions. Homology modeling results suggested that the protein-binding activity was affected by dephosphorylation, and the S197/S198/S202 residues of PsnERF may be the key phosphorylation sites influencing its binding ability.