Function of the syndecan-4 cytoplasmic domain in oligomerization and association with α-actinin in turkey muscle satellite cells.
Syndecan-4 (S4) is a cell membrane heparan sulfate proteoglycan that plays a role in satellite cell mediated myogenesis. S4 modulates the proliferation of myogenic satellite cells, but the mechanism of how S4 functions during myogenesis is not well understood. In other cell systems, S4 has been shown to form oligomers in the cell membrane and interact through its cytoplasmic domain with the cytoskeletal protein α-actinin. This study addressed if S4 forms oligomers and interacts with α-actinin in muscle. The S4 cytoplasmic domain was found to interact with α-actinin in a phosphatidylinositol-4,5-bisphosphate dependent manner, but did not associate with vinculin. Through confocal microscopy, both S4 and syndecan-4 without the cytoplasmic domain were localized to the cell membrane. Although the cytoplasmic domain was necessary for the interaction with α-actinin, S4 oligomer formation occurred in the absence of the cytoplasmic domain. These data indicated that S4 function in skeletal muscle is mediated through the formation of oligomers and interaction with the cytoskeletal protein α-actinin.
Department of Animal Sciences, Ohio Agricultural Research and Development Center, The Ohio State University, 213 Gerlaugh Hall, 1680 Madison Avenue, Wooster, OH 44691, USA.
Jonghyun
J
Shin
Yan
Y
Song
Douglas C
DC
McFarland
Sandra G
SG
Velleman
D000185:Actinin / Q000378:metabolism*; D000818:Animals; D002462:Cell Membrane / Q000378:metabolism; D002478:Cells, Cultured; D003593:Cytoplasm / Q000378:metabolism*; D008297:Male; D018613:Microscopy, Confocal; D019269:Phosphatidylinositol 4,5-Diphosphate / Q000378:metabolism; D054730:Protein Interaction Domains and Motifs; D025941:Protein Interaction Mapping; D055503:Protein Multimerization; D017434:Protein Structure, Tertiary; D034622:RNA Interference; D032496:Satellite Cells, Skeletal Muscle / Q000378:metabolism*; D053671:Syndecan-4 / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D014162:Transfection; D014422:Turkeys; D016596:Vinculin / Q000378:metabolism
D019269:Phosphatidylinositol 4,5-Diphosphate; D053671:Syndecan-4; D000185:Actinin; D016596:Vinculin