title: JM4 is a four-transmembrane protein binding to the CCR5 receptor.
abstract: The CC chemokine receptor 5 (CCR5) is a major co-receptor for human immunodeficiency virus (HIV) and CCR5 mutants lacking the carboxy (C)-terminus interfere with HIV infection. Therefore, we analysed the C-terminus of CCR5 and here describe Jena-Muenchen 4 (JM4), a novel CCR5-interacting protein. JM4 is membrane-associated, co-precipitates with CCR5, and is ubiquitously expressed. It shares about 62% sequence similarity with JWA and glutamate transporter-associated protein 3-18 (GTRAP3-18), a regulator of an amino acid transporter. JWA, like JM4, is a four-transmembrane protein, which binds to the CCR5 receptor. Furthermore, JM4, JWA, and GTRAP3-18 co-localise and heterodimerise indicating a functional relationship. JM4 co-localises with calnexin in the endoplasmic reticulum and with the mannose 6-phosphate receptor in the Golgi. JM4 and GTRAP3-18 harbor a Rab-acceptor motif, indicating a function in vesicle formation at the Golgi complex. In conclusion, we describe a CCR5-interacting protein, which is suggested to function in trafficking and membrane localisation of the receptor, possibly also other receptors or amino acid transporters.
authors.affiliation: Institute of Medical Virology, University Zurich, Gloriastr. 30, 8028 Zürich, Switzerland.
authors.forename: Marc
authors.initials: M
authors.lastname: Schweneker
authors.forename: André S
authors.initials: AS
authors.lastname: Bachmann
authors.forename: Karin
authors.initials: K
authors.lastname: Moelling
mesh_terms: D000595:Amino Acid Sequence; D001665:Binding Sites; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism*; D002460:Cell Line; D015870:Gene Expression; D006801:Humans; D047468:Immunoprecipitation; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D019713:Receptors, CCR5 / Q000235:genetics / Q000378:metabolism*; D015728:Receptors, HIV / Q000235:genetics / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid; D014018:Tissue Distribution; D014162:Transfection; D020798:Two-Hybrid System Techniques
chemical_list: D002352:Carrier Proteins; D008565:Membrane Proteins; C499863:PRAF2 protein, human; D019713:Receptors, CCR5; D015728:Receptors, HIV