Cleavage of host keratin 8 by a Chlamydia-secreted protease.
Chlamydiae have to replicate within a cytoplasmic vacuole in eukaryotic cells. Expansion of the chlamydia-laden vacuole is essential for chlamydial intravacuolar replication, which inevitably causes host cell cytoskeleton rearrangements. A cleavage fragment of keratin 8 corresponding to the central rod region was detected in the soluble fraction of chlamydia-infected cells. Since keratin 8 is a major component of the intermediate filaments in simple epithelial cells, cleavage of keratin 8 may increase the solubility of the host cell cytoskeleton and thus permit vacuole expansion in chlamydia-infected cells. A chlamydia-secreted protease designated CPAF (chlamydial protease/proteasome-like activity factor) was both necessary and sufficient for keratin 8 cleavage in chlamydia-infected cells, suggesting that chlamydiae have evolved specific mechanisms for modifying the host cell cytoskeleton.
Dong
Feng
F
Department of Microbiology and Immunology, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, San Antonio, TX 78229, USA.
Su
Heng
H
Huang
Yanqing
Y
Zhong
Youmin
Y
Zhong
Guangming
G
D002689:Chlamydia / Q000201:enzymology* / Q000378:metabolism; D002690:Chlamydia Infections / Q000201:enzymology* / Q000378:metabolism; D003600:Cytosol / Q000378:metabolism; D010450:Endopeptidases / Q000378:metabolism*; D006367:HeLa Cells; D006790:Host-Parasite Interactions / Q000502:physiology; D006801:Humans; D053533:Keratin-8; D007633:Keratins / Q000378:metabolism*
C426203:KRT8 protein, human; D053533:Keratin-8; D007633:Keratins; D010450:Endopeptidases