Role and Regulation of Clp Proteases: A Target against Gram-Positive Bacteria

Abstract

Bacterial proteases participate in the proteolytic elimination of misfolded or aggregated proteins, carried out by members of the AAA+ protein superfamily such as Hsp100/Clp, Lon, and FtsH. It is estimated that the Clp and Lon families perform around 80% of cellular proteolysis in bacteria. These functions are regulated, in part, through the spatial and/or temporal use of adapter proteins, which participate in the recognition and delivery of specific substrate proteins to proteases. The proteolysis plays an important role in maintaining and controlling the quality of the proteins, avoiding the accumulation and aggregation of unfolded or truncated proteins. However, this is not their only function, since they play an important role in the formation of virulent phenotypes and in the response to different types of stress faced when entering the host or that occur in the environment. This review summarizes the structural and functional aspects of the Clp proteases and their role in Gram-positive microorganisms.

Comparative Genomics of Staphylococcus rostri, an Undescribed Bacterium Isolated from Dairy Mastitis

“…All 81 isolates and the S. rostri DSM 21968 strain carried two putative virulence genes: the ATP-dependent protease subunits clpP and clpC ( Table S4 ). Overall, the Clp family of ATPases plays a crucial role in the folding, assembly, and degradation of proteins, and thereby maintenance of homeostasis [ 36 ]. While the clpP gene is well-conserved in most bacterial species, the clpC gene is usually found in Gram-positive bacteria specifically.…”

“…While the clpP gene is well-conserved in most bacterial species, the clpC gene is usually found in Gram-positive bacteria specifically. The two genes can associate to form a proteolytic complex (i.e., ClpCP), which can regulate virulence in Gram-positive bacteria regarding, e.g., stress tolerance, biofilm formation, and motility [ 36 , 37 ]. However, in the present study, the clpP and clpC genes were not detected in the same contig for any of the isolates (nor in S. rostri DSM 21968 strain), and thereby they were presumably not forming such a complex; thus, their exact virulence properties in S. rostri remain uncertain.…”