Increased expression of the 43-kD protein disrupts acetylcholine receptor clustering in myotubes.
The 43-kD protein is a peripheral membrane protein that is in approximately 1:1 stoichiometry with the acetylcholine receptor (AChR) in vertebrate muscle cells and colocalizes with it in the postsynaptic membrane. To investigate the role of the 43-kD protein in AChR clustering, we have isolated C2 muscle cell lines in which some cells overexpress the 43-kD protein. We find that myotubes with increased levels of the 43-kD protein have small AChR clusters and that those with the highest levels of expression have a drastically reduced number of clusters. Our results suggest that the 1:1 stoichiometry of AChR and 43-kD protein found in muscle cells is important for AChR cluster formation.
Yoshihara
C M
CM
Department of Physiology, University of California, San Francisco 94143-0444.
Hall
Z W
ZW
D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D002999:Clone Cells; D004247:DNA; D000939:Epitopes / Q000032:analysis; D015870:Gene Expression; D005822:Genetic Vectors; D008565:Membrane Proteins / Q000032:analysis / Q000096:biosynthesis / Q000378:metabolism*; D008969:Molecular Sequence Data; D009124:Muscle Proteins / Q000096:biosynthesis / Q000378:metabolism*; D009132:Muscles / Q000378:metabolism*; D009838:Oligodeoxyribonucleotides; D011950:Receptors, Cholinergic / Q000032:analysis / Q000378:metabolism*; D011994:Recombinant Proteins / Q000032:analysis / Q000096:biosynthesis / Q000378:metabolism; D014162:Transfection
D000939:Epitopes; D008565:Membrane Proteins; D009124:Muscle Proteins; D009838:Oligodeoxyribonucleotides; D011950:Receptors, Cholinergic; D011994:Recombinant Proteins; C051609:peripheral membrane protein 43K; D004247:DNA