ClpXP and ClpAP proteolytic activity on divisome substrates is differentially regulated following the Caulobacter asymmetric cell division. Issue 5 (7th August 2014)

• Record Type: Journal Article
• Authors: Williams, Brandon; Bhat, Nowsheen; Chien, Peter; Shapiro, Lucy
• Is Part Of: Molecular microbiology. Volume 93:Issue 5(2014)
• Page Start: 853
• Page End: 866
• Publication Date: 2014-08-07
• Subjects: Molecular microbiology -- Periodicals; 572.829
• DOI: 10.1111/mmi.12698
• Languages: English
• ISSNs: 0950-382X

Abstract

<abstract abstract-type="main"> <title>Summary</title> <p>Proteolytic control of <italic>C</italic><italic>aulobacter</italic> cell cycle proteins is primarily executed by ClpXP, a dynamically localized protease implicated in turnover of several factors critical for faithful cell cycle progression. Here, we show that the transient midcell localization of ClpXP that precedes cytokinesis requires the FtsZ component of the divisome. Although ClpAP does not exhibit subcellular localization, FtsZ is a substrate of both ClpXP and ClpAP <italic>in vivo</italic> and <italic>in vitro</italic>. A peptide containing the C‐terminal portion of the FtsA divisome protein is a substrate of both ClpXP and ClpAP <italic>in vitro</italic> but is primarily degraded by ClpAP <italic>in vivo</italic>. <italic>C</italic><italic>aulobacter</italic> carries out an asymmetric division in which FtsZ and FtsA are stable in stalked cells but degraded in the non‐replicative swarmer cell where ClpAP alone degrades FtsA and both ClpAP and ClpXP degrade FtsZ. While asymmetric division in <italic>C</italic><italic>aulobacter</italic> normally yields larger stalked and smaller swarmer daughters, we observe a loss of asymmetric size distribution among daughter cells when <italic>clpA</italic> is depleted from a strain in which FtsZ is constitutively produced. Taken together, these results suggest that the activity of both ClpXP and ClpAP on divisome substrates is differentially regulated in daughter cells.</p> </abstract>