title: Immunohistochemical Localization of an Isoform of TRK-Fused Gene-Like Protein in the Rat Retina.
abstract: The TRK-fused gene (TFG) was originally identified in chromosome translocation events, creating a pair of oncogenes in some cancers, and was recently demonstrated as the causal gene of hereditary motor and sensory neuropathy with proximal dominant involvement. Recently, we cloned an alternative splicing variant of Tfg from a cDNA library of the rat retina, tentatively naming it retinal Tfg (rTfg). Although the common form of Tfg is ubiquitously expressed in most rat tissues, rTfg expression is localized to the central nervous system. In this study, we produced an antibody against an rTFG-specific amino acid sequence and used it to examine the localization of rTFG-like protein in the rat retina by immunohistochemistry and Western blots. Western blot analysis showed that the antibody detected a single band of 24 kDa in the rat retina. When we examined rTFG recombinant protein, the antibody detected two bands of about 42 kDa and 24 kDa. The results suggest that the 24 kDa rTFG-like protein is a fragment of rTFG. In our immunohistochemical studies of the rat retina, rTFG-like immunoreactivity was observed in all calbindin D-28K-positive horizontal cells and in some syntaxin 1-positive amacrine cells (ACs). In addition, the rTFG-like immunopositive ACs were actually glycine transporter 1-positive glycinergic or glutamate decarboxylase-positive GABAergic ACs. Our findings indicate that this novel 24 kDa rTFG-like protein may play a specific role in retinal inhibitory interneurons.
authors.affiliation: Molecular Neuroscience Research Center, Shiga University of Medical Science , Seta Tsukinowa-cho, Otsu 520-2192, Japan.
authors.forename: Chiaki
authors.initials: C
authors.lastname: Masuda
authors.affiliation: Molecular Neuroscience Research Center, Shiga University of Medical Science , Seta Tsukinowa-cho, Otsu 520-2192, Japan.
authors.forename: Shigeko
authors.initials: S
authors.lastname: Takeuchi
authors.affiliation: Molecular Neuroscience Research Center, Shiga University of Medical Science , Seta Tsukinowa-cho, Otsu 520-2192, Japan.
authors.forename: Naomi
authors.initials: N
authors.lastname: J Bisem
authors.affiliation: Division of Neurological Science, Department of Psychiatry, Faculty of Medicine, The University of British Columbia , Vancouver BC, V6T 1Z3 Canada.
authors.forename: Steven
authors.initials: S
authors.lastname: R Vincent
authors.affiliation: Molecular Neuroscience Research Center, Shiga University of Medical Science , Seta Tsukinowa-cho, Otsu 520-2192, Japan.
authors.forename: Ikuo
authors.initials: I
authors.lastname: Tooyama
keywords: amacrine cells; antibodies; horizontal cells; immunohistochemistry; retina