Caseinolytic protease P subunit (ClpP)

Caseinolytic protease P subunit (ClpP) is a highly conserved serine protease that forms the proteolytic core of the ATP-dependent Clp protease complex in bacteria, mitochondria, and chloroplasts[2][4][5][6]. It typically assembles into a tetradecameric barrel-shaped structure composed of two heptameric rings, forming a compartmentalized chamber that sequesters catalytic sites and enables regulated protein degradation[2][3][4][5][6][7]. The biological activity of ClpP is tightly controlled by AAA+ ATPase chaperones (such as ClpX, ClpA, or ClpC), which recognize, unfold, and translocate target proteins carrying specific degradation signals (degrons) into the proteolytic core[2][4][6][7]. ClpP is essential for the turnover of misfolded and damaged proteins, thereby maintaining protein homeostasis (proteostasis), and is involved in the regulated degradation of key cellular regulators, adaptation to stress, pathogenesis, and bacterial virulence[2][5][6]. In several pathogenic bacteria, two isoforms of ClpP (ClpP1 and ClpP2) can form heteromeric complexes that are essential for full proteolytic function and pathogenesis[1][3][4][7]. Because of its indispensable role in cell viability and virulence, ClpP has emerged as a promising target for novel antibiotics, including activators (e.g., acyldepsipeptides) that deregulate proteolytic control to induce toxic protein degradation in bacteria, even in non-dividing or dormant cells, and combination therapies targeting persistent bacterial infections[5][7]. Homologs of ClpP are found in eukaryotic mitochondria and plastids, with similar roles in maintaining organellar protein quality control[4][6][9].

Other names

ATP-dependent Clp protease proteolytic subunitCaseinolytic proteaseClp proteaseEndopeptidase ClpCLPP (gene)

Allosteric activation (e.g., by ADEP class compounds), Proteolysis of regulatory proteins (often through dysregulated activation), Combination therapy (e.g., ADEP with rifampicin causes extensive bacterial self-destruction)