A Clp/Hsp100 chaperone functions in Myxococcus xanthus sporulation and self-Organization

Abstract

The Clp/Hsp100 proteins are chaperones that play a role in protein degradation and reactivation. In bacteria, they exhibit a highdegree of pleiotropy, affecting both individual and multicellular phenotypes. In this article, we present the first characterizationof a Clp/Hsp100 homolog in Myxococcus xanthus (MXAN_4832 gene locus). Deletion of MXAN_4832 causes defects in bothswarming and aggregation related to cell motility and the production of fibrils, which are an important component of the extracellularmatrix of a swarm. The deletion also affects the formation of myxospores during development, causing them to becomesensitive to heat. The protein product of MXAN_4832 can act as a chaperone in vitro, providing biochemical evidence in supportof our hypothesis that MXAN_4832 is a functional Clp/Hsp100 homolog. There are a total of 12 Clp/Hsp100 homologs in M.xanthus, including MXAN_4832, and, based on its mutational and biochemical characterization, they may well represent an importantgroup. © 2012, American Society for Microbiology.