title: Isoform-specific interaction of golgin-160 with the Golgi-associated protein PIST.
abstract: Golgin-160 belongs to the golgin family of Golgi-localized proteins, which have been implicated in Golgi structure and function. Golgin-160 possesses an N-terminal non-coiled-coil "head" domain followed by an extensive coiled-coil region. Using the N-terminal head domain of golgin-160 as bait in a yeast two-hybrid screen, the postsynaptic density-95/Discs large/zona occludens-1 (PDZ) domain protein interacting specifically with TC10 (PIST) was identified to interact with golgin-160. PIST (also known as GOPC, CAL, and FIG) has been implicated in the trafficking of a subset of plasma membrane proteins, supporting a role of golgin-160 in vesicular trafficking. Golgin-160 and PIST colocalize to Golgi membranes and interact in vivo. Glutathione S-transferase binding experiments identified an internal region of PIST that includes a coiled-coil domain, which interacts directly with golgin-160. Similar binding experiments identified a leucine-rich repeat within golgin-160 necessary for interaction with PIST. Therefore, our data suggest that golgin-160 may participate in PIST-dependent trafficking of cargo. Interestingly, we also discovered a widely expressed isoform of golgin-160, golgin-160B, which lacks the exon encoding the leucine repeat that mediates binding to PIST. As predicted, golgin-160B was unable to bind PIST. Full-length golgin-160 and golgin-160B may link distinct subsets of proteins to effect specific membrane trafficking pathways.
authors.affiliation: Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
authors.forename: Stuart W
authors.initials: SW
authors.lastname: Hicks
authors.forename: Carolyn E
authors.initials: CE
authors.lastname: Machamer
mesh_terms: D048868:Adaptor Proteins, Signal Transducing; D000595:Amino Acid Sequence; D000818:Animals; D001324:Autoantigens / Q000737:chemistry* / Q000378:metabolism; D002352:Carrier Proteins / Q000378:metabolism*; D002462:Cell Membrane / Q000378:metabolism; D018076:DNA, Complementary / Q000378:metabolism; D005091:Exons; D019084:Fluorescent Antibody Technique, Indirect; D005982:Glutathione Transferase / Q000378:metabolism; D006056:Golgi Apparatus / Q000378:metabolism; D000077614:Golgi Matrix Proteins; D049452:Green Fluorescent Proteins / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D047468:Immunoprecipitation; D007930:Leucine / Q000737:chemistry; D008565:Membrane Proteins / Q000737:chemistry* / Q000378:metabolism*; D026901:Membrane Transport Proteins; D008957:Models, Genetic; D008969:Molecular Sequence Data; D009154:Mutation; D011485:Protein Binding; D020033:Protein Isoforms; D017434:Protein Structure, Tertiary; D012333:RNA, Messenger / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017386:Sequence Homology, Amino Acid; D020798:Two-Hybrid System Techniques
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D001324:Autoantigens; D002352:Carrier Proteins; D018076:DNA, Complementary; C108388:GOLGA3 protein, human; C434484:GOPC protein, human; D000077614:Golgi Matrix Proteins; D008565:Membrane Proteins; D026901:Membrane Transport Proteins; D020033:Protein Isoforms; D012333:RNA, Messenger; D049452:Green Fluorescent Proteins; D005982:Glutathione Transferase; D007930:Leucine