Denervation supersensitivity in skeletal muscle: analysis with a cloned cDNA probe.
Motor neurons regulate the acetylcholine sensitivity of the muscles they innervate: denervated muscle fiber become "supersensitive" to acetylcholine, due to insertion of newly synthesized acetylcholine receptors (AChRs) in the plasma membrane. We used hybridization analysis with a cloned cDNA specific for AChR alpha-subunit to compare the abundance of AChR mRNA in innervated and denervated adult mouse muscles. Within 3 d of denervation, levels of AChR mRNA increased 100-fold; levels of actin mRNA changed little. The increase in AChR mRNA level was sufficiently large and rapid to account for denervation supersensitivity.
D000199:Actins / Q000235:genetics; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D004247:DNA / Q000378:metabolism*; D005260:Female; D051379:Mice; D009046:Motor Neurons / Q000378:metabolism; D009121:Muscle Denervation; D009132:Muscles / Q000648:ultrastructure*; D009693:Nucleic Acid Hybridization; D012333:RNA, Messenger / Q000378:metabolism; D011950:Receptors, Cholinergic / Q000235:genetics; D013997:Time Factors
D000199:Actins; D012333:RNA, Messenger; D011950:Receptors, Cholinergic; D004247:DNA