TAX1-binding protein 1 is expressed in the retina and interacts with the GABA C} receptor {rho}1 subunit

Melanie Ulrich , Silke Seeber , Cord-Michael Becker , Ralf Enz (1)

1 Institut für Biochemie

Macromolecular signaling complexes that link neurotransmitter receptors to functionally and structurally associated proteins play an important role in the regulation of neurotransmission. Thus, the identification of proteins binding to neurotransmitter receptors describes molecular mechanisms of synaptic signal transduction. To identify interacting proteins of GABA C} receptors in the retina, we used antibodies specific for GABA C} receptor {rho}1-3 subunits. Analysis of immunoprecipitated proteins by MALDI-TOF mass spectrometry identified the liver regeneration-related protein 2 that is identical to amino acids 253-813 of the Tax1 binding protein Tax1BP1. A C-terminal region of Tax1BP1 bound to an intracellular domain of the {rho}1 subunit, but not to other subunits of GABA C}, GABA A} or glycine receptors. Confocal laser-scanning microscopy demonstrated co-localization of Tax1BP1 and {rho}1 in clusters at the cell membrane of transfected cells. Furthermore, Tax1BP1 and GABA C} receptors were co-expressed in both synaptic layers of the retina, indicating that Tax1BP1 is a component of GABA C} receptor containing signal complexes.

Mots clés: Life Sciences

Melanie Ulrich, Silke Seeber, Cord-Michael Becker, Ralf Enz. TAX1-binding protein 1 is expressed in the retina and interacts with the GABA C} receptor {rho}1 subunit. Biochemical Journal, 2006, 401 (2), pp.429-436. ⟨10.1042/BJ20061036⟩. ⟨hal-00478627⟩