title: Identification of brain-specific angiogenesis inhibitor 2 as an interaction partner of glutaminase interacting protein.
abstract: The vast majority of physiological processes in living cells are mediated by protein-protein interactions often specified by particular protein sequence motifs. PDZ domains, composed of 80-100 amino acid residues, are an important class of interaction motif. Among the PDZ-containing proteins, glutaminase interacting protein (GIP), also known as Tax Interacting Protein TIP-1, is unique in being composed almost exclusively of a single PDZ domain. GIP has important roles in cellular signaling, protein scaffolding and modulation of tumor growth and interacts with a number of physiological partner proteins, including Glutaminase L, β-Catenin, FAS, HTLV-1 Tax, HPV16 E6, Rhotekin and Kir 2.3. To identify the network of proteins that interact with GIP, a human fetal brain cDNA library was screened using a yeast two-hybrid assay with GIP as bait. We identified brain-specific angiogenesis inhibitor 2 (BAI2), a member of the adhesion-G protein-coupled receptors (GPCRs), as a new partner of GIP. BAI2 is expressed primarily in neurons, further expanding GIP cellular functions. The interaction between GIP and the carboxy-terminus of BAI2 was characterized using fluorescence, circular dichroism (CD) and nuclear magnetic resonance (NMR) spectroscopy assays. These biophysical analyses support the interaction identified in the yeast two-hybrid assay. This is the first study reporting BAI2 as an interaction partner of GIP.
authors.affiliation: Department of Biochemistry, Faculty of Science, Ege University, Izmir, Turkey.
authors.forename: Sevil
authors.initials: S
authors.lastname: Zencir
authors.forename: Mohiuddin
authors.initials: M
authors.lastname: Ovee
authors.forename: Melanie J
authors.initials: MJ
authors.lastname: Dobson
authors.forename: Monimoy
authors.initials: M
authors.lastname: Banerjee
authors.forename: Zeki
authors.initials: Z
authors.lastname: Topcu
authors.forename: Smita
authors.initials: S
authors.lastname: Mohanty
mesh_terms: D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins / Q000378:metabolism*; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism*; D010455:Peptides / Q000235:genetics / Q000378:metabolism; D013050:Spectrometry, Fluorescence; D020798:Two-Hybrid System Techniques
chemical_list: C111499:ADGRB2 protein, human; D047908:Intracellular Signaling Peptides and Proteins; D009419:Nerve Tissue Proteins; D010455:Peptides; C421249:TAX1BP3 protein, human