CPAF: A Chlamydial Protease in Search of an Authentic Substrate |
| |
| Authors: | Allan L Chen Kirsten A Johnson Jennifer K Lee Christine S��tterlin Ming Tan |
| |
| Institution: | 1Department of Microbiology and Molecular Genetics, University of California at Irvine, Irvine, California, United States of America;2Department of Developmental and Cell Biology, University of California at Irvine, Irvine, California, United States of America;3Department of Medicine, University of California at Irvine, Irvine, California, United States of America |
| |
| Abstract: | Bacteria in the genus Chlamydia are major human pathogens that cause an intracellular infection. A chlamydial protease, CPAF, has been proposed as an important virulence factor that cleaves or degrades at least 16 host proteins, thereby altering multiple cellular processes. We examined 11 published CPAF substrates and found that there was no detectable proteolysis when CPAF activity was inhibited during cell processing. We show that the reported proteolysis of these putative CPAF substrates was due to enzymatic activity in cell lysates rather than in intact cells. Nevertheless, Chlamydia-infected cells displayed Chlamydia-host interactions, such as Golgi reorganization, apoptosis resistance, and host cytoskeletal remodeling, that have been attributed to CPAF-dependent proteolysis of host proteins. Our findings suggest that other mechanisms may be responsible for these Chlamydia-host interactions, and raise concerns about all published CPAF substrates and the proposed roles of CPAF in chlamydial pathogenesis. |
| |
| Keywords: | |
|
|
