title: Direct association of the reticulon protein RTN1A with the ryanodine receptor 2 in neurons.
abstract: RTN1A is a reticulon protein with predominant localization in the endoplasmic reticulum (ER). It was previously shown that RTN1A is expressed in neurons of the mammalian central nervous system but functional information remains sparse. To elucidate the neuronal function of RTN1A, we chose to focus our investigation on identifying possible novel binding partners specifically interacting with the unique N-terminus of RTN1A. Using a nonbiased approach involving GST pull-downs and MS analysis, we identified the intracellular calcium release channel ryanodine receptor 2 (RyR2) as a direct binding partner of RTN1A. The RyR2 binding site was localized to a highly conserved 150-amino acid residue region. RTN1A displays high preference for RyR2 binding in vitro and in vivo and both proteins colocalize in hippocampal neurons and Purkinje cells. Moreover, we demonstrate the precise subcellular localization of RTN1A in Purkinje cells and show that RTN1A inhibits RyR channels in [(3)H]ryanodine binding studies on brain synaptosomes. In a functional assay, RTN1A significantly reduced RyR2-mediated Ca(2+) oscillations. Thus, RTN1A and RyR2 might act as functional partners in the regulation of cytosolic Ca(2+) dynamics the in neurons.
authors: Division of Neurobiochemistry, Biocenter, Innsbruck Medical University, Innsbruck, Austria.
authors: Levent
authors: L
authors: Kaya
authors: Barbara
authors: B
authors: Meissner
authors: Maria Christine
authors: MC
authors: Riedl
authors: Martin
authors: M
authors: Muik
authors: Christoph
authors: C
authors: Schwarzer
authors: Francesco
authors: F
authors: Ferraguti
authors: Bettina
authors: B
authors: Sarg
authors: Herbert
authors: H
authors: Lindner
authors: Rüdiger
authors: R
authors: Schweigreiter
authors: Hans-Günther
authors: HG
authors: Knaus
authors: Christoph
authors: C
authors: Romanin
authors: Christine E
authors: CE
authors: Bandtlow
mesh_terms: D000818:Animals; D001665:Binding Sites; D015153:Blotting, Western; D002118:Calcium / Q000378:metabolism*; D002478:Cells, Cultured; D003600:Cytosol / Q000378:metabolism; D006624:Hippocampus / Q000166:cytology / Q000378:metabolism*; D006801:Humans; D007124:Immunoenzyme Techniques; D047468:Immunoprecipitation; D008297:Male; D051379:Mice; D009419:Nerve Tissue Proteins / Q000378:metabolism*; D009474:Neurons / Q000166:cytology / Q000378:metabolism*; D011485:Protein Binding; D051381:Rats; D017207:Rats, Sprague-Dawley; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D012433:Ryanodine / Q000378:metabolism; D019837:Ryanodine Receptor Calcium Release Channel / Q000378:metabolism*; D053719:Tandem Mass Spectrometry
chemical_list: D009419:Nerve Tissue Proteins; D011993:Recombinant Fusion Proteins; C489914:Rtn1 protein, mouse; D019837:Ryanodine Receptor Calcium Release Channel; D012433:Ryanodine; D002118:Calcium