title: Calcitonin gene-related peptide induces the expression of acetylcholinesterase-associated collagen ColQ in muscle: a distinction in driving two different promoters between fast- and slow-twitch muscle fibers.
abstract: The presence of a collagenous protein (ColQ) characterizes the collagen-tailed forms of acetylcholinesterase at vertebrate neuromuscular junctions (nmjs). Two ColQ transcripts as ColQ-1 and ColQ-1a, driven by two promoters: pColQ-1 and pColQ-1a, were found in mammalian slow- and fast-twitch muscles, respectively, which have distinct expression pattern in different muscle fibers. In this study, we show the differential expression of CoQ in different muscles is triggered by calcitonin gene-related peptide (CGRP), a known motor neuron-derived factor. Application of CGRP, or dibutyryl-cAMP (Bt(2)-cAMP), in cultured myotubes induced the expression of ColQ-1a transcript and promoter activity; however, the expression of ColQ-1 transcript did not respond to CGRP or Bt(2)-cAMP. The CGRP-induced gene activation was blocked by an adenylyl cyclase inhibitor or a dominant negative mutant of cAMP-responsive element (CRE) binding protein (CREB). Two CRE sites were mapped within the ColQ-1a promoter, and mutations of the CRE sites abolished the response of CGRP or Bt(2)-cAMP. In parallel, CGRP receptor complex was dominantly expressed at the nmjs of fast muscle but not of slow muscle. These results suggested that the expression of ColQ-1a at the nmjs of fast-twitch muscle was governed by a CGRP-mediated cAMP signaling mechanism.
authors.affiliation: Departments of Biology and Molecular Neuroscience Center, The Hong Kong University of Science and Technology, Clear Water Bay Road, Hong Kong, China.
authors.forename: Roy C Y
authors.initials: RC
authors.lastname: Choi
authors.forename: Annie K L
authors.initials: AK
authors.lastname: Ting
authors.forename: Faye T C
authors.initials: FT
authors.lastname: Lau
authors.forename: Heidi Q
authors.initials: HQ
authors.lastname: Xie
authors.forename: K Wing
authors.initials: KW
authors.lastname: Leung
authors.forename: Vicky P
authors.initials: VP
authors.lastname: Chen
authors.forename: Nina L
authors.initials: NL
authors.lastname: Siow
authors.forename: Karl W K
authors.initials: KW
authors.lastname: Tsim
mesh_terms: D000110:Acetylcholinesterase / Q000378:metabolism*; D000818:Animals; D003994:Bucladesine / Q000494:pharmacology; D050882:CREB-Binding Protein / Q000378:metabolism; D015740:Calcitonin Gene-Related Peptide / Q000494:pharmacology*; D002478:Cells, Cultured; D002642:Chick Embryo; D002645:Chickens; D047369:Chromatin Immunoprecipitation / Q000379:methods; D004305:Dose-Response Relationship, Drug; D024202:Electrophoretic Mobility Shift Assay / Q000379:methods; D005786:Gene Expression Regulation / Q000187:drug effects; D049452:Green Fluorescent Proteins / Q000378:metabolism; D006801:Humans; D032342:Muscle Cells / Q000166:cytology*; D018656:Muscle Fibers, Fast-Twitch / Q000187:drug effects*; D018657:Muscle Fibers, Slow-Twitch / Q000187:drug effects*; D011401:Promoter Regions, Genetic / Q000187:drug effects / Q000502:physiology; D018015:Receptors, Calcitonin Gene-Related Peptide / Q000378:metabolism; D011950:Receptors, Cholinergic / Q000378:metabolism; D013997:Time Factors; D015533:Transcriptional Activation; D014162:Transfection / Q000379:methods
chemical_list: D018015:Receptors, Calcitonin Gene-Related Peptide; D011950:Receptors, Cholinergic; D049452:Green Fluorescent Proteins; D003994:Bucladesine; D050882:CREB-Binding Protein; D000110:Acetylcholinesterase; D015740:Calcitonin Gene-Related Peptide