October 31, 2014 at 3:40 pm

PBIO Colloquium: ‘Wall Associated Kinases As Pectin Receptors Mediate Both Growth And Stress Responses By Distinct Pathways,’ Oct. 31

The Environmental & Plant Biology Colloquium Series presents Dr. Bruce Kohorn on “Wall Associated Kinases As Pectin Receptors Mediate Both Growth And Stress Responses By Distinct Pathways” on Friday, Oct. 31, at 11:50 a.m. in Porter Hall 104.

Dr. Bruce Kohorn

Kohorn is the Linnean Professor of Biology and Biochemistry and Director of Biochemistry at Bowdoin College in Brunswick, ME.

Abstract: The wall-associated kinases, WAKs, are encoded by five highly similar genes clustered in a 30-kblocus in Arabidopsis. These receptor-like proteins contain a cytoplasmic serine threonine kinase, a trans membrane domain, and a less conserved region that is bound to the cell wall and contains a series of epidermal growth factor repeats. Evidence is emerging that WAKs serve as pectin receptors, for both short oligo galacturonic acid fragments (OGs) generated during pathogen exposure or wounding, and for longer pectins resident in native cell walls. This ability to bind and respond to several types of pectins correlates with a demonstrated role for WAKs in both the pathogen response and cell expansion during plant development. These two distinct pathways of growth and stress are distinguished by the activation of MPK3 versus MAPK6 by WAK, and lead to different gene expression patterns. Both biochemical and genetic evidence support this model for parallel pathways activated by various forms of pectin binding to WAKs. Genetic interactions between receptors coexpressed with WAK identify potential components of these signaling pathways.