Involvement of the transmembrane protein p23 in biosynthetic protein transport

Article Article scientifique Article Involvement of the transmembrane protein p23 in biosynthetic protein transport eng 1997 author Rojo Ortiz De Lanzagorta Manuel 91130 author Pepperkok Rainer 51778 author Emery Gregory 87786 author Kellner Roland author Stang Roland author Parton Robert author Gruenberg Jean 29661 1119-1135 10.1083/jcb.139.5.1119 0021-9525 Here, we report the localization and characterization of BHKp23, a member of the p24 family of transmembrane proteins, in mammalian cells. We find that p23 is a major component of tubulovesicular membranes at the cis side of the Golgi complex (estimated density: 12,500 copies/μm2 membrane surface area, or ≈30% of the total protein). Our data indicate that BHKp23-containing membranes are part of the cis-Golgi network/intermediate compartment. Using the G protein of vesicular stomatitis virus as a transmembrane cargo molecule, we find that p23 membranes are an obligatory station in forward biosynthetic membrane transport, but that p23 itself is absent from transport vesicles that carry the G protein to and beyond the Golgi complex. Our data show that p23 is not present to any significant extent in coat protein (COP) I-coated vesicles generated in vitro and does not colocalize with COP I buds and vesicles. Moreover, we find that p23 cytoplasmic domain is not involved in COP I membrane recruitment. Our data demonstrate that microinjected antibodies against the cytoplasmic tail of p23 inhibit G protein transport from the cis- Golgi network/intermediate compartment to the cell surface, suggesting that p23 function is required for the transport of transmembrane cargo molecules. These observations together with the fact that p23 is a highly abundant component in the intermediate compartment, lead us to propose that p23 contributes to membrane structure, and this contribution is necessary for efficient segregation and transport. Dewey 540 Dewey 570 46 Département de biologie cellulaire 165 39 Département de biochimie 144 false The Journal of cell biology 139 5 995962c1-460c-4fea-b285-d659d1953347 Article (Published version) Public ROJO_TJCB_19971135.pdf 1239331 application/pdf CC BY-NC-SA openAccess Faculté des sciences / Section de biologie / Département de biologie cellulaire Faculté des sciences / Section de chimie et biochimie / Département de biochimie

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Involvement of the transmembrane protein p23 in biosynthetic protein transport	The Journal of cell biology			1997	138	214

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Emery, Gregory