Functional characterization of Melampsora larici‐populina Hog1‐type MAPK in response to osmotic stress

Abstract

Yeast growth is limited under high external osmolarity, and the highosmolarity glycerol (HOG) mitogen-activated protein kinase (MAPK) pathway from Saccharomyces cerevisiae is a comprehensively understood osmoresponsive system (Hohmann, 2002). In this pathway, two independent upstream branches converge on the MAPK kinase Pbs2. Activated Pbs2 phosphorylates the core MAPK Hog1, which is the homologue of mammalian p38 stress-activated protein kinase (SAPK). S. cerevisiae Hog1 is responsible mainly for the accumulation of glycerol in the presence of high osmolarity (Albertyn et al., 1994).In response to osmostress, S. cerevisiae Hog1 is rapidly activated and then imported into the nucleus to conduct multiple types of