The Escherichia coli DjlA and CbpA Proteins Can Substitute for DnaJ in DnaK-Mediated Protein Disaggregation
Abstract
The Escherichia coli DjlA and CbpA Proteins Can Substitute for DnaJ in DnaK-Mediated Protein Disaggregation Eyal Gur 1 , Dvora Biran 1 , Nelia Shechter 1 , Pierre Genevaux 2 , Costa Georgopoulos 2 , and Eliora Z. Ron 1 , * 1 Department of Molecular Microbiology and Biotechnology, George S. Wise Faculty of Life Sciences, Tel-Aviv University, Tel-Aviv, Israel 2 Département de Microbiologie et Médecine Moléculaire, Centre Médical Universitaire, Université de Genève, Geneva, Switzerland ABSTRACT The DnaJ (Hsp40) protein of Escherichia coli serves as a cochaperone of DnaK (Hsp70), whose activity is involved in protein folding, protein targeting for degradation, and rescue of proteins from aggregates. Two other E. coli proteins, CbpA and DjlA, which exhibit homology with DnaJ, are known to interact with DnaK and to stimulate its chaperone activity. Although it has been shown that in dnaJ mutants both CbpA and DjlA are essential for growth at temperatures above 37°C, their in vivo role is poorly understood. Here we show that in a dnaJ mutant both CbpA and DjlA are required for efficient protein dissaggregation at 42°C.