title: Huntingtin and huntingtin-associated protein 1 influence neuronal calcium signaling mediated by inositol-(1,4,5) triphosphate receptor type 1.
abstract: Huntington's disease (HD) is caused by polyglutamine expansion (exp) in huntingtin (Htt). The type 1 inositol (1,4,5)-triphosphate receptor (InsP3R1) is an intracellular calcium (Ca2+) release channel that plays an important role in neuronal function. In a yeast two-hybrid screen with the InsP3R1 carboxy terminus, we isolated Htt-associated protein-1A (HAP1A). We show that an InsP3R1-HAP1A-Htt ternary complex is formed in vitro and in vivo. In planar lipid bilayer reconstitution experiments, InsP3R1 activation by InsP3 is sensitized by Httexp, but not by normal Htt. Transfection of full-length Httexp or caspase-resistant Httexp, but not normal Htt, into medium spiny striatal neurons faciliates Ca2+ release in response to threshold concentrations of the selective mGluR1/5 agonist 3,5-DHPG. Our findings identify a novel molecular link between Htt and InsP3R1-mediated neuronal Ca2+ signaling and provide an explanation for the derangement of cytosolic Ca2+ signaling in HD patients and mouse models.
authors.affiliation: Department of Physiology, University of Texas Southwestern Medical Center at Dallas, Dallas, TX 75390, USA.
authors.forename: Tie-Shan
authors.initials: TS
authors.lastname: Tang
authors.forename: Huiping
authors.initials: H
authors.lastname: Tu
authors.forename: Edmond Y W
authors.initials: EY
authors.lastname: Chan
authors.forename: Anton
authors.initials: A
authors.lastname: Maximov
authors.forename: Zhengnan
authors.initials: Z
authors.lastname: Wang
authors.forename: Cheryl L
authors.initials: CL
authors.lastname: Wellington
authors.forename: Michael R
authors.initials: MR
authors.lastname: Hayden
authors.forename: Ilya
authors.initials: I
authors.lastname: Bezprozvanny
mesh_terms: D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D015153:Blotting, Western; D002118:Calcium / Q000378:metabolism; D015220:Calcium Channels / Q000378:metabolism*; D020013:Calcium Signaling / Q000502:physiology*; D002478:Cells, Cultured; D002531:Cerebellum / Q000378:metabolism; D002540:Cerebral Cortex / Q000378:metabolism; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D016257:Fura-2 / Q000378:metabolism; D049452:Green Fluorescent Proteins; D006801:Humans; D000071058:Huntingtin Protein; D006816:Huntington Disease / Q000378:metabolism; D015544:Inositol 1,4,5-Trisphosphate / Q000494:pharmacology; D053496:Inositol 1,4,5-Trisphosphate Receptors; D008051:Lipid Bilayers; D008164:Luminescent Proteins / Q000378:metabolism; D008734:Methoxyhydroxyphenylglycol / Q000031:analogs & derivatives* / Q000494:pharmacology; D009419:Nerve Tissue Proteins / Q000302:isolation & purification / Q000378:metabolism / Q000502:physiology*; D009474:Neurons / Q000187:drug effects / Q000378:metabolism / Q000502:physiology*; D009687:Nuclear Proteins / Q000378:metabolism / Q000502:physiology*; D018408:Patch-Clamp Techniques; D010446:Peptide Fragments / Q000378:metabolism; D010957:Plasmids / Q000378:metabolism; D011485:Protein Binding; D018160:Receptors, Cytoplasmic and Nuclear / Q000378:metabolism*; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D013997:Time Factors; D020798:Two-Hybrid System Techniques
chemical_list: D015220:Calcium Channels; C096896:HAP1 protein, human; C086055:HTT protein, human; C490758:Hap1 protein, mouse; D000071058:Huntingtin Protein; C506926:ITPR1 protein, human; D053496:Inositol 1,4,5-Trisphosphate Receptors; D008051:Lipid Bilayers; D008164:Luminescent Proteins; D009419:Nerve Tissue Proteins; D009687:Nuclear Proteins; D010446:Peptide Fragments; D018160:Receptors, Cytoplasmic and Nuclear; D011994:Recombinant Proteins; D049452:Green Fluorescent Proteins; D008734:Methoxyhydroxyphenylglycol; D015544:Inositol 1,4,5-Trisphosphate; D002118:Calcium; D016257:Fura-2; C010117:3,4-dihydroxyphenylglycol