title: GIP, a G-protein-coupled receptor interacting protein.
abstract: A novel protein was cloned while screening for partners interacting with the second intracellular loop of the V2 vasopressin receptor (V2R). The protein was named GIP as in G-protein-coupled receptor Interacting Protein; the corresponding gene was located on the 17th chromosome where three exons encode for a 379-amino-acid protein.GIP subcellular localization was studied by immunocytochemistry and also using a biotinylating agent. The protein was found to be localized, at least in part, on the plasma membrane, probably in the form of a trimer. The results indicated that GIP is a transmembrane protein and the most part of the molecule is intracellular. Sequence homology inferred that GIP cytosolic domain is folded as a collagen-like helix followed by a globular domain. The interaction of the globular domain with the V2R was confirmed by pull-down experiments indicating that this structural motif can also interact with cytosolic proteins.
authors.affiliation: Scientific Institute San Raffaele, Universtita' Vita-Salute, Milan, Italy. giulio.innamorati@hsr.it
authors.forename: Giulio
authors.initials: G
authors.lastname: Innamorati
authors.forename: Michael Insuk
authors.initials: MI
authors.lastname: Whang
authors.forename: Raffaella
authors.initials: R
authors.lastname: Molteni
authors.forename: Christian
authors.initials: C
authors.lastname: Le Gouill
authors.forename: Mariel
authors.initials: M
authors.lastname: Birnbaumer
mesh_terms: D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D001483:Base Sequence; D002352:Carrier Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D003001:Cloning, Molecular; D020869:Gene Expression Profiling; D008969:Molecular Sequence Data; D009928:Organ Specificity; D011485:Protein Binding; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D017483:Receptors, Vasopressin / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid; D020798:Two-Hybrid System Techniques; D011506:Proteins
chemical_list: D002352:Carrier Proteins; D012333:RNA, Messenger; D017483:Receptors, Vasopressin; C512356:C1QTNF1 protein, human; D011506:Proteins