Tvp38, Tvp23, Tvp18 and Tvp15: novel membrane proteins in the Tlg2-containing Golgi/endosome compartments of Saccharomyces cerevisiae.

Department of Biotechnology, University of Tokyo, Yayoi, Bunkyo-Ku, Tokyo 113-8657, Japan.
Experimental Cell Research (Impact Factor: 3.37). 03/2007; 313(4):688-97. DOI: 10.1016/j.yexcr.2006.11.008
Source: PubMed

ABSTRACT Four previously uncharacterized proteins (Tvp38, Tvp23, Tvp18 and Tvp15) were found in Tlg2-containing membrane by proteomic analysis of immunoisolated Golgi subcompartments of Saccharomyces cerevisiae (Inadome et al., Mol. Cell. Biol., 25 (2005) 7696-7710). Immunofluorescence double staining of HA-tagged Tvp proteins and myc-tagged tSNAREs supported that these proteins mainly localize in the Tlg2-containing compartments. Conserved sequences of Tvp38, Tvp23 and Tvp18 are found in higher eukaryotes, but these homologues have not been characterized yet. All Tvp proteins were nonessential for growth under laboratory conditions. Immunoprecipitation of Tvp proteins indicated that Tvp23, Tvp18 and Tvp15 are in an interactive network with Yip1-family proteins, Yip4 and Yip5. They may collectively assist in the effective maintenance/function of the late Golgi/endosomal compartments. Disruptions of tvp15 and tvp23 showed synthetic aggravation with ypt6 or ric1 null mutation. Processing of carboxypeptidase Y and alkaline phosphatase in tvp disruptants occurred as in the wild type.

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    • "ins , yeast YIP4p interacts with TVP23p , the yeast ortholog of ECH ( Gendre et al . , 2011 ) , as demonstrated by Y2H ( Uetz et al . , 2000 ; Ito et al . , 2001 ) and co - IP ( Inadome et al . , 2007 ) . Moreover , ECH and YIP4 localizations are also conserved across species , as both TVP23p and YIP4p localize to the late Golgi / early endosome ( Inadome et al . , 2007 ) , which corresponds to the plant TGN . Thus , ECH and YIP4a / b localizations and interaction have been conserved through evolution between the organisms as distant as yeast and plants , indicating their functional impor - tance for vesicle trafficking ."
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