title: The cAMP-dependent protein kinase mediates the expression of AChE in chick myotubes.
abstract: Calcitonin gene-related peptide (CGRP), a neuropeptide synthesized by motor neurons, stimulates the expression of AChR and AChE at the vertebrate neuromuscular junctions. The signaling mechanism of CGRP-induced AChE expression in muscle was determined both in vitro and in vivo. In cultured chick myotubes, the intracellular cAMP-dependent protein kinase (PKA) activity increased to approximately 2-fold after the application of CGRP or PKA activators; the induction was blocked by PKA inhibitors. in vivo transfection analysis on chick gastrocnemius muscles showed that the transfection of cDNA encoding constitutively active mutant Galphas increased the expression of AChE mRNA and protein to approximately 2-fold, while the constitutively active mutant Galphai cDNA transfection showed an opposite effect. The induced catalytic subunit of AChE at approximately 105 kDa was determined by specific antibody. These findings indicate that the CGRP-induced AChE expression in chick muscle is mediated by a PKA-dependent pathway.
authors.affiliation: Department of Biology and Biotechnology Research Institute, The Hong Kong University of Science and Technology, Kowloon, China.
authors.forename: R C
authors.initials: RC
authors.lastname: Choi
authors.forename: N L
authors.initials: NL
authors.lastname: Siow
authors.forename: S Q
authors.initials: SQ
authors.lastname: Zhu
authors.forename: K W
authors.initials: KW
authors.lastname: Tsim
mesh_terms: D000110:Acetylcholinesterase / Q000187:drug effects* / Q000235:genetics*; D000818:Animals; D015740:Calcitonin Gene-Related Peptide / Q000378:metabolism* / Q000494:pharmacology*; D018929:Cell Culture Techniques; D002642:Chick Embryo; D000242:Cyclic AMP / Q000378:metabolism* / Q000494:pharmacology*; D017868:Cyclic AMP-Dependent Protein Kinases / Q000187:drug effects* / Q000378:metabolism*; D019204:GTP-Binding Proteins / Q000235:genetics / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects* / Q000502:physiology*; D018485:Muscle Fibers, Skeletal / Q000166:cytology* / Q000187:drug effects / Q000201:enzymology*; D018482:Muscle, Skeletal / Q000166:cytology / Q000196:embryology* / Q000201:enzymology*
chemical_list: D000242:Cyclic AMP; D017868:Cyclic AMP-Dependent Protein Kinases; D000110:Acetylcholinesterase; D019204:GTP-Binding Proteins; D015740:Calcitonin Gene-Related Peptide