title: GRIF-1 and OIP106, members of a novel gene family of coiled-coil domain proteins: association in vivo and in vitro with kinesin.
abstract: Gamma-aminobutyric acid(A) receptor-interacting factor (GRIF-1) is a 913-amino acid protein proposed to function as a GABA(A) receptor beta(2) subunit-interacting, trafficking protein. GRIF-1 shares approximately 44% amino acid sequence identity with O-linked N-acetylglucosamine transferase interacting protein 106, OIP106. Both proteins contain predicted coiled-coil domains and probably constitute a novel gene family. The Drosophila orthologue of this family of proteins may be Milton. Milton shares approximately 44% amino acid homology with GRIF-1. Milton is proposed to function in kinesin-mediated transport of mitochondria to nerve terminals. We report here that GRIF-1 and OIP106 also associate with kinesin and mitochondria. Following expression in human embryonic kidney 293 cells, both GRIF-1 and OIP106 were shown by co-immunoprecipitation to be specifically associated with an endogenous kinesin heavy chain species of 115 kDa and exogenous KIF5C. Association of GRIF-1 with kinesin was also evident in native brain and heart tissue. In the brain, anti-GRIF-1-(8-633) antibodies specifically co-immunoprecipitated two kinesin-immunoreactive species with molecular masses of 118 and 115 kDa, and in the heart, one kinesin-immunoreactive species, 115 kDa, was immunoprecipitated. Further studies revealed that GRIF-1 was predominantly associated with KIF5A in the brain and with KIF5B in both the heart and in HEK 293 cells. Yeast two-hybrid interaction assays and immunoprecipitations showed that GRIF-1 associated directly with KIF5C with the GRIF-1/KIF5C interaction domain localized to GRIF-1-(124-283). These results further support a role for GRIF-1 and OIP106 in protein and/or organelle transport in excitable cells in a manner analogous to glutamate receptor-interacting-protein 1, in the motor-dependent transport of alpha-amino-3-hydroxy-5-methylisoxazole-4-propionate glutamate excitatory neurotransmitter receptors to dendrites.
authors.affiliation: Department of Pharmaceutical and Biological Chemistry, School of Pharmacy, University of London, 29/39 Brunswick Square, London WC1N 1AX, United Kingdom.
authors.forename: Kieran
authors.initials: K
authors.lastname: Brickley
authors.forename: Miriam J
authors.initials: MJ
authors.lastname: Smith
authors.forename: Mike
authors.initials: M
authors.lastname: Beck
authors.forename: F Anne
authors.initials: FA
authors.lastname: Stephenson
mesh_terms: D000117:Acetylglucosamine / Q000737:chemistry; D000818:Animals; D001692:Biological Transport; D001921:Brain / Q000378:metabolism; D002352:Carrier Proteins / Q000737:chemistry / Q000502:physiology*; D002460:Cell Line; D003712:Dendrites / Q000378:metabolism; D003902:Detergents / Q000494:pharmacology; D018698:Glutamic Acid / Q000737:chemistry; D006801:Humans; D015151:Immunoblotting; D007150:Immunohistochemistry; D047468:Immunoprecipitation; D047908:Intracellular Signaling Peptides and Proteins; D016547:Kinesins / Q000378:metabolism; D008954:Models, Biological; D017351:N-Acetylglucosaminyltransferases / Q000737:chemistry / Q000502:physiology*; D009419:Nerve Tissue Proteins; D018377:Neurotransmitter Agents / Q000378:metabolism; D017830:Octoxynol / Q000494:pharmacology; D010455:Peptides / Q000737:chemistry; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D014162:Transfection; D020798:Two-Hybrid System Techniques
chemical_list: D002352:Carrier Proteins; D003902:Detergents; D047908:Intracellular Signaling Peptides and Proteins; D009419:Nerve Tissue Proteins; D018377:Neurotransmitter Agents; D010455:Peptides; C465341:TRAK2 protein, human; D018698:Glutamic Acid; D017830:Octoxynol; D017351:N-Acetylglucosaminyltransferases; C473288:Trak1 protein, rat; D016547:Kinesins; D000117:Acetylglucosamine