title: Host complement regulatory protein CD59 is transported to the chlamydial inclusion by a Golgi apparatus-independent pathway.
abstract: Chlamydia is an obligate intracellular bacterium that grows and replicates inside a cytoplasmic inclusion. We report that a host protein, CD59, which regulates complement function at the surfaces of uninfected cells, can be detected at the membrane of the chlamydial inclusion. This localization to the inclusion membrane was specific for CD59 and not a general feature of other glycosylphosphatidylinositol (GPI)-anchored proteins or representative cell surface proteins. Using differential permeabilization studies, we showed that CD59 is localized to the luminal but not the cytoplasmic face of the inclusion membrane, consistent with membrane association via its GPI anchor. Furthermore, CD59 was present at the inclusion even when we prevented it from associating with membrane microdomains via the GPI anchor or when we inhibited general protein transport to the cell surface, indicating that a conventional Golgi apparatus-dependent trafficking mechanism was not involved. Based on these findings, we propose that selected host proteins are trafficked to the inclusion by a Golgi apparatus-independent pathway during a Chlamydia infection.
authors.affiliation: Department of Developmental and Cell Biology, University of California, Irvine, 3128 Natural Sciences I, Irvine, CA 92697-2300, USA.
authors.forename: Ayako
authors.initials: A
authors.lastname: Hasegawa
authors.forename: L Farah
authors.initials: LF
authors.lastname: Sogo
authors.forename: Ming
authors.initials: M
authors.lastname: Tan
authors.forename: Christine
authors.initials: C
authors.lastname: Sütterlin
mesh_terms: D000818:Animals; D001692:Biological Transport; D018957:CD59 Antigens / Q000378:metabolism*; D016466:CHO Cells; D002692:Chlamydia trachomatis / Q000472:pathogenicity*; D006224:Cricetinae; D003412:Cricetulus; D006056:Golgi Apparatus / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D002479:Inclusion Bodies / Q000378:metabolism*; D021962:Membrane Microdomains
chemical_list: D018957:CD59 Antigens