Cellular localization and subcellular distribution of Unc-33-like protein 6, a brain-specific protein of the collapsin response mediator protein family that interacts with the neuronal glycine transporter 2.
Unc-33-like protein (Ulip)6, a brain-specific phosphoprotein of the Ulip/collapsin response mediator protein family, was originally identified in our laboratory by yeast two-hybrid screening using the cytoplasmic N-terminal domain of the neuronal glycine transporter, glycine transporter (GlyT) 2, as a bait. Here, the interaction of Ulip6 with the N-terminal domain of GlyT2 was found to be specific for this member of the Ulip/collapsin response mediator protein family and to involve amino acids 135-184 of GlyT2. In pull-down assays and coimmunoprecipitation experiments with rat spinal cord extract, the presence of phosphatase inhibitors significantly enhanced binding of Ulip6 to GlyT2. Subcellular fractionation of spinal cord and retina homogenates at different developmental stages showed Ulip6 immunoreactivity to be associated with light vesicles that were distinct from GlyT2-containing and synaptic vesicles. Immunocytochemistry revealed punctate Ulip6 immunoreactivity in both somatic regions and processes of cultured spinal neurones; no colocalization with GlyT2 or other synaptic marker proteins was found. In retina, which expresses only GlyT1 but not GlyT2, Ulip6 was detected in the inner plexiform layer and along the somata and processes of selected bipolar, amacrine and ganglion cells. Our data support a model in which Ulip6 transiently interacts with GlyT2 in a phosphorylation-dependent manner.
Abteilung Neurochemie, Max-Planck-Institut für Hirnforschung, Frankfurt am Main, Germany.
Masahisa
M
Horiuchi
Sven
S
Loebrich
Johann Helmut
JH
Brandstaetter
Matthias
M
Kneussel
Heinrich
H
Betz
D048868:Adaptor Proteins, Signal Transducing / Q000378:metabolism; D000367:Age Factors; D026921:Amino Acid Transport Systems, Neutral / Q000737:chemistry / Q000378:metabolism*; D000818:Animals; D000831:Animals, Newborn; D015153:Blotting, Western / Q000379:methods; D001921:Brain / Q000166:cytology / Q000378:metabolism; D002478:Cells, Cultured; D004622:Embryo, Mammalian; D050487:Glycine Plasma Membrane Transport Proteins; D007150:Immunohistochemistry / Q000379:methods; D047468:Immunoprecipitation / Q000379:methods; D009419:Nerve Tissue Proteins / Q000378:metabolism*; D009474:Neurons / Q000166:cytology* / Q000378:metabolism; D011485:Protein Binding / Q000187:drug effects; D017434:Protein Structure, Tertiary / Q000502:physiology; D012333:RNA, Messenger / Q000378:metabolism; D011869:Radioligand Assay / Q000379:methods; D051381:Rats; D012160:Retina / Q000166:cytology / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods; D040121:Semaphorin-3A / Q000378:metabolism*; D013116:Spinal Cord / Q000166:cytology* / Q000378:metabolism; D013347:Subcellular Fractions / Q000378:metabolism*; D020798:Two-Hybrid System Techniques; D015003:Yeasts
D048868:Adaptor Proteins, Signal Transducing; D026921:Amino Acid Transport Systems, Neutral; C413755:Dpysl5 protein, rat; D050487:Glycine Plasma Membrane Transport Proteins; D009419:Nerve Tissue Proteins; D012333:RNA, Messenger; D040121:Semaphorin-3A; C493269:Slc6a5 protein, rat; C493266:Slc6a9 protein, rat