Functional Cooperativity between the Trigger Factor Chaperone and the ClpXP Proteolytic Complex

• Published in: The FASEB journal Vol. 35; no. S1
• Main Authors: Houry, Walid, Rizzolo, Kamran
• Format: Journal Article
• Language: English
• Published: The Federation of American Societies for Experimental Biology 01-05-2021
• ISSN: 0892-6638; 1530-6860
• DOI: 10.1096/fasebj.2021.35.S1.02156

A functional association is uncovered between the ribosome‐associated trigger factor (TF) chaperone and the ClpXP degradation complex. Bioinformatic analyses demonstrates conservation of the close proximity of tig, gene coding for TF, and genes coding for ClpXP suggesting a functional interaction. Effect of TF on ClpXP‐dependent degradation varies based on the nature of substrate. While degradation of some substrates are slowed down or are unaffected by TF, surprisingly, TF increases the degradation rate of a third class of substrates. These include λ phage replication protein λO, master regulator of stationary phase RpoS, and SsrA‐tagged proteins. Globally, TF acts to enhance the degradation of about 2% of newly synthesized proteins. TF is found to interact through multiple sites with ClpX in a highly dynamic fashion to promote protein degradation. This chaperone‐protease cooperation constitutes a unique and likely ancestral aspect of cellular protein homeostasis in which TF acts as an adaptor for ClpXP.