The ATP-dependent protease ClpYQ degrades cell division proteins DivIVA and Mbl in Bacillus subtilis

Abstract

ATP-dependent proteases play key roles in bacterial protein quality control and regulation of cellular processes. ClpYQ and ClpXP are ATP-dependent proteases in the Gram-positive bacteria Bacillus subtilis. To date, no substrate proteins of B. subtilis ClpYQ have been characterized. The protease component encoded by clpQ is synthetically lethal with clpP and the two genes are non-essential individually, suggesting potentially redundant roles for ClpYQ and ClpXP. Previous quantitative proteomic data predicted that B. subtilis proteins DivIVA and Mbl, components of the divisome and elongasome respectively, are potential substrates of ClpYQ. The role of DivIVA and Mbl in cell division and elongation suggests a significant role of ClpYQ in regulating cell division through targeted degradation of key divisome and elongasome proteins. Here we confirm that DivIVA and Mbl are degraded by ClpYQ both in vitro and in vivo, and thus identify the first two substrates of ClpYQ in B. subtilis.