title: Cleavage of host keratin 8 by a Chlamydia-secreted protease.
abstract: 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.
authors.affiliation: Department of Microbiology and Immunology, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, San Antonio, TX 78229, USA.
authors.forename: Feng
authors.initials: F
authors.lastname: Dong
authors.forename: Heng
authors.initials: H
authors.lastname: Su
authors.forename: Yanqing
authors.initials: Y
authors.lastname: Huang
authors.forename: Youmin
authors.initials: Y
authors.lastname: Zhong
authors.forename: Guangming
authors.initials: G
authors.lastname: Zhong
mesh_terms: 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*
chemical_list: C426203:KRT8 protein, human; D053533:Keratin-8; D007633:Keratins; D010450:Endopeptidases