Disease relevance of PBS1

• Specific recognition of Pseudomonas syringae strains that express the avirulence gene avrPphB requires two genes in Arabidopsis, RPS5 and PBS1 [1].

High impact information on PBS1

• AvrPphB has a very stringent substrate specificity, catalyzing a single proteolytic cleavage in the Arabidopsis serine/threonine kinase PBS1 [2].
• We discuss several possible models for the roles of PBS1 and RPS5 in AvrPphB recognition [1].
• Here we report that PBS1 encodes a putative serine-threonine kinase [1].
• DNA sequence analysis of the pbs1-2 allele showed it to be a missense mutation that caused a glycine to arginine substitution in the activation segment of PBS1, a region known to regulate substrate binding and catalytic activity in many protein kinases [1].
• Comparison of the predicted PBS1 amino acid sequence with other plant protein kinases revealed that PBS1 belongs to a distinct subfamily of protein kinases that contains no other members of known function [1].

Chemical compound and disease context of PBS1

• In Arabidopsis, resistance to Pseudomonas syringae strains expressing AvrPphB requires RPS5, a member of the class of R proteins that have a predicted nucleotide-binding site and leucine-rich repeats, and PBS1, a protein kinase [3].

Biological context of PBS1

• Mutations in PBS1 completely blocked RPS5-mediated resistance, but had little to no effect on resistance specified by other disease resistance genes, suggesting that PBS1 facilitates recognition of the avrPphB protein [4].
• The pbs mutations are recessive and have been mapped to chromosomes I (pbs2) and V (pbs1 and pbs3) [4].
• Southern blot analysis revealed that the pbs1-1 allele contained a deletion of the 3' end of the PBS1 open reading frame [1].

Other interactions of PBS1

• By screening for loss of RPS5-specified resistance, we identified five pbs (avrPphB susceptible) mutants that represent three different genes [4].

References