title: Induction of insulin-like growth factor 1 splice forms by subfragments of myofibrillar proteins.
abstract: Expression of insulin-like growth factor 1 (IGF-1) mRNAs splice forms was recently shown to be stimulated by myofibrillar proteins released from the damaged muscle. In this study, we report that individual subfragments of titin and myomesin composed of Fn type III and Ig-like domains can activate expression of two IGF-1 splice forms in cultured myoblasts, both at protein and mRNA levels. Competition studies showed that each of the domain-types interacts with its own receptor. Induction of IGF-1 expression caused by domains of different types showed dissimilar sensitivity to inhibitors of regulatory cascades. The effect of Fn type III domains was more sensitive to inhibition of Ca(2+)/calmodulin dependent protein kinase, whereas the effect of Ig-like domains showed greater sensitivity to the inhibition of the adenylyl cyclase-cAMP-PKA pathway.
authors.affiliation: Bach Institute of Biochemistry, Russian Academy of Sciences, Leninskiy Prospect 33, 119071 Moscow, Russia.
authors.forename: Irina V
authors.initials: IV
authors.lastname: Kravchenko
authors.affiliation: Bach Institute of Biochemistry, Russian Academy of Sciences, Leninskiy Prospect 33, 119071 Moscow, Russia.
authors.forename: Vladimir A
authors.initials: VA
authors.lastname: Furalyov
authors.affiliation: European Molecular Biology Laboratory, Hamburg Unit, c/o DESY, Notkestraße 85, 22603 Hamburg, Germany.
authors.forename: Spyros
authors.initials: S
authors.lastname: Chatziefthimiou
authors.affiliation: European Molecular Biology Laboratory, Hamburg Unit, c/o DESY, Notkestraße 85, 22603 Hamburg, Germany.
authors.forename: Matthias
authors.initials: M
authors.lastname: Wilmanns
authors.affiliation: Bach Institute of Biochemistry, Russian Academy of Sciences, Leninskiy Prospect 33, 119071 Moscow, Russia; Kurchatov NBIC Centre, Russian National Research Centre "Kurchatov Institute", Akademika Kurchatova sq. 1, 123182 Moscow, Russia. Electronic address: vpopov@inbi.ras.ru.
authors.forename: Vladimir O
authors.initials: VO
authors.lastname: Popov
mesh_terms: D017398:Alternative Splicing / Q000187:drug effects*; D064211:Connectin / Q000494:pharmacology*; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000096:biosynthesis* / Q000235:genetics; D032446:Myoblasts / Q000166:cytology / Q000378:metabolism*; D017434:Protein Structure, Tertiary; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics
chemical_list: D064211:Connectin; C583557:IGF1 protein, human; D012333:RNA, Messenger; C577285:TTN protein, human; D007334:Insulin-Like Growth Factor I
keywords: Fn type III domain; Ig-like domain; Insulin-like growth factor 1; Mechano-growth factor; Myomesin; Titin