Title A rule governing the FtsH-mediated proteolysis of the MgtC virulence protein from Salmonella enterica serovar Typhimurium
Author Jonghyun Baek, Eunna Choi, and Eun-Jin Lee
Address Department of Genetic Engineering and Graduate School of Biotechnology, College of Life Sciences, Kyung Hee University, Yongin 17104, Republic of Korea
Bibliography Journal of Microbiology, 56(8),565–570, 2018,
DOI 10.1007/s12275-018-8245-6
Key Words mgtC, FtsH protease, post-translational regulation
Abstract A tightly controlled turnover of membrane proteins is required for lipid bilayer stability, cell metabolism, and cell viability. Among the energy-dependent AAA+ proteases in Salmonella, FtsH is the only membrane-bound protease that contributes to the quality control of membrane proteins. FtsH preferentially degrades the C-terminus or N-terminus of misfolded, misassembled, or damaged proteins to maintain physiological functions. We found that FtsH hydrolyzes the Salmonella MgtC virulence protein when we substitute the MgtC 226th Trp, which is well conserved in other intracellular pathogens and normally protects MgtC from the FtsH-mediated proteolysis. Here we investigate a rule determining the FtsHmediated proteolysis of the MgtC protein at Trp226 residue. Substitution of MgtC tryptophan 226th residue to alanine, glycine, or tyrosine leads to MgtC proteolysis in a manner dependent on the FtsH protease whereas substitution to phenylalanine, methionine, isoleucine, leucine, or valine resists MgtC degradation by FtsH. These data indicate that a large and hydrophobic side chain at 226th residue is required for protection from the FtsH-mediated MgtC proteolysis.