Abstract
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
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Research Support, Non-U.S. Gov't
MeSH terms
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Adaptor Proteins, Signal Transducing
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Amino Acid Sequence
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Animals
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Brain / physiology*
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COS Cells
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Cell Adhesion / physiology
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Cell Adhesion Molecules
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Cell Adhesion Molecules, Neuronal / chemistry*
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Chromosome Mapping
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Chromosomes, Human, Pair 3 / genetics
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Cloning, Molecular
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Drosophila Proteins*
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Guanylate Kinases
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Humans
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Immunohistochemistry
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In Situ Hybridization, Fluorescence
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Insect Proteins / chemistry
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Molecular Sequence Data
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Neovascularization, Physiologic / physiology*
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Nerve Tissue Proteins / chemistry*
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Nucleoside-Phosphate Kinase / chemistry
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RNA, Messenger / metabolism
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Recombinant Fusion Proteins / genetics
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Sequence Homology, Amino Acid
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Signal Transduction / physiology
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Transfection / genetics
Substances
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Adaptor Proteins, Signal Transducing
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Cell Adhesion Molecules
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Cell Adhesion Molecules, Neuronal
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Drosophila Proteins
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Insect Proteins
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Nerve Tissue Proteins
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RNA, Messenger
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Recombinant Fusion Proteins
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cno protein, Drosophila
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Nucleoside-Phosphate Kinase
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Guanylate Kinases
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MAGI1 protein, human