title: Fibroblast growth factor 2 and protein kinase C alpha are involved in syndecan-4 cytoplasmic domain modulation of turkey myogenic satellite cell proliferation.
abstract: Syndecan-4 core protein is composed of extracellular, transmembrane, and cytoplasmic domains. The cytoplasmic domain functions in transmitting signals into the cell through the protein kinase C alpha (PKCα) pathway. The glycosaminoglycan (GAG) and N-linked glycosylated (N-glycosylated) chains attached to the extracellular domain influence cell proliferation. The current study investigated the function of syndecan-4 cytoplasmic domain in combination with GAG and N-glycosylated chains in turkey muscle cell proliferation, differentiation, fibroblast growth factor 2 (FGF2) responsiveness, and PKCα membrane localization. Syndecan-4 or syndecan-4 without the cytoplasmic domain and with or without the GAG and N-glycosylated chains were transfected or co-transfected with a small interfering RNA targeting syndecan-4 cytoplasmic domain into turkey muscle satellite cells. The overexpression of syndecan-4 mutants increased cell proliferation but did not change differentiation. Syndecan-4 mutants had increased cellular responsiveness to FGF2 during proliferation. Syndecan-4 increased PKCα cell membrane localization, whereas the syndecan-4 mutants decreased PKCα cell membrane localization compared to syndecan-4. However, compared to the cells without transfection, syndecan-4 mutants increased cell membrane localization of PKCα. These data indicated that the syndecan-4 cytoplasmic domain and the GAG and N-glycosylated chains are critical in syndecan-4 regulating satellite cell proliferation, responsiveness to FGF2, and PKCα cell membrane localization.
authors.affiliation: Department of Animal Sciences, Ohio Agricultural Research and Development Center, The Ohio State University, Wooster, OH 44691, USA. song.249@osu.edu
authors.forename: Yan
authors.initials: Y
authors.lastname: Song
authors.forename: Douglas C
authors.initials: DC
authors.lastname: McFarland
authors.forename: Sandra G
authors.initials: SG
authors.lastname: Velleman
mesh_terms: D000818:Animals; D002454:Cell Differentiation; D002462:Cell Membrane; D049109:Cell Proliferation; D002478:Cells, Cultured; D016222:Fibroblast Growth Factor 2 / Q000235:genetics / Q000378:metabolism*; D005786:Gene Expression Regulation; D006025:Glycosaminoglycans / Q000235:genetics / Q000378:metabolism; D016297:Mutagenesis, Site-Directed; D050505:Mutant Proteins / Q000235:genetics / Q000378:metabolism*; D051571:Protein Kinase C-alpha / Q000235:genetics / Q000378:metabolism*; D017434:Protein Structure, Tertiary; D032496:Satellite Cells, Skeletal Muscle / Q000166:cytology / Q000378:metabolism*; D015398:Signal Transduction; D053671:Syndecan-4 / Q000235:genetics / Q000378:metabolism*; D014422:Turkeys / Q000235:genetics / Q000378:metabolism*
chemical_list: D006025:Glycosaminoglycans; D050505:Mutant Proteins; D053671:Syndecan-4; D016222:Fibroblast Growth Factor 2; D051571:Protein Kinase C-alpha