Cloning and characterization of BAI-associated protein 1: a PDZ domain-containing protein that interacts with BAI1

Biochem Biophys Res Commun. 1998 Jun 29;247(3):597-604. doi: 10.1006/bbrc.1998.8603.


Brain-specific angiogenesis inhibitor 1 (BAI1), which is a p53-target gene specifically expressed in brain, encodes a seven-span transmembrane protein. Using a two-hybrid system, we isolated a cDNA that encodes a protein, named BAP1 (BAI1-associated protein), which interacts with the cytoplasmic region of BAI1. BAP1 is a novel member of the MAGUK (membrane-associated guanylate kinase homologue) family; it possesses a guanylate kinase domain, WW domains, and multiple PDZ domains. Interaction between BAI1 and BAP1 was mediated by a QTEV motif in the carboxy-terminal region of BAI1 and PDZ domains of BAP1. By immunocytochemical analysis of COS-7 cells transfected with BAI1 and BAP1, both products were co-localized at the cytoplasmic membrane, especially at cell-cell junctions. Cells transfected with BAI1 formed filopodia-like cytoplasmic extensions. These results suggest that BAI1 and BAP1 might be involved in cell adhesion and signal transduction in brain.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adaptor Proteins, Signal Transducing
  • Amino Acid Sequence
  • Animals
  • Brain / physiology*
  • COS Cells
  • Cell Adhesion / physiology
  • Cell Adhesion Molecules
  • Cell Adhesion Molecules, Neuronal / chemistry*
  • Chromosome Mapping
  • Chromosomes, Human, Pair 3 / genetics
  • Cloning, Molecular
  • Drosophila Proteins*
  • Guanylate Kinases
  • Humans
  • Immunohistochemistry
  • In Situ Hybridization, Fluorescence
  • Insect Proteins / chemistry
  • Molecular Sequence Data
  • Neovascularization, Physiologic / physiology*
  • Nerve Tissue Proteins / chemistry*
  • Nucleoside-Phosphate Kinase / chemistry
  • RNA, Messenger / metabolism
  • Recombinant Fusion Proteins / genetics
  • Sequence Homology, Amino Acid
  • Signal Transduction / physiology
  • Transfection / genetics


  • Adaptor Proteins, Signal Transducing
  • Cell Adhesion Molecules
  • Cell Adhesion Molecules, Neuronal
  • Drosophila Proteins
  • Insect Proteins
  • Nerve Tissue Proteins
  • RNA, Messenger
  • Recombinant Fusion Proteins
  • cno protein, Drosophila
  • Nucleoside-Phosphate Kinase
  • Guanylate Kinases
  • MAGI1 protein, human

Associated data

  • GENBANK/AB010894