Actin at receptor-rich domains of isolated acetylcholine receptor clusters

doi:10.1083/jcb.102.4.1447

This Article

	Full Text (PDF, 1568K)
	Alert me when this article is cited
	Citation Map

Services

	Email this article
	Similar articles in this journal
	Similar articles in PubMed
	Alert me to new content in the JCB
	Download to citation manager

Citing Articles

	Citing Articles via HighWire
	Citing Articles via CrossRef
	Citing Articles via Google Scholar

Google Scholar

	Articles by Bloch, R. J.
	Search for Related Content

PubMed

	PubMed Citation
	Articles by Bloch, R. J.


Social Bookmarking

	What's this?

ARTICLES

Actin at receptor-rich domains of isolated acetylcholine receptor clusters

RJ Bloch

Acetylcholine receptor (AChR) clusters of cultured rat myotubes, isolated by extraction with saponin (Bloch, R. J., 1984, J. Cell Biol. 99:984-993), contain a polypeptide that co-electrophoreses with purified muscle actins. A monoclonal antibody against actin reacts in immunoblots with this polypeptide and with purified actins. In indirect immunofluorescence, the antibody stains isolated AChR clusters only at AChR domains, strips of membrane within clusters that are rich in receptor. It also stains the postsynaptic region of the neuromuscular junction of adult rat skeletal muscle. Semiquantitative immunofluorescence analyses show that labeling by antiactin of isolated analyses show that labeling by antiactin of isolated AChR clusters is specific and saturable and that it varies linearly with the amount of AChR in the cluster. Filaments of purified gizzard myosin also bind preferentially at AChR-rich regions, and this binding is inhibited by MgATP. These experiments suggest that actin is associated with AChR- rich regions of receptor clusters. Depletion of actin by extraction of isolated clusters at low ionic strength selectively releases the actin- like polypeptide from the preparation. Simultaneously, AChRs redistribute within the plane of the membrane of the isolated clusters. Similarly, brief digestion with chymotrypsin reduces immunofluorescence staining and causes AChR redistribution. Treatments that deplete AChR from clusters in intact cells also reduce immunofluorescent staining for actin in isolated muscle membrane fragments. Upon reversal of these treatments, cluster reformation occurs in regions of the membrane that also stain for actin. I conclude that actin is associated with AChR domains and that changes in this association are accompanied by changes in the organization of isolated AChR clusters.
Add to CiteULike CiteULike Add to Complore Complore Add to Connotea Connotea Add to Del.icio.us Del.icio.us Add to Digg Digg Facebook Add to Reddit Reddit Add to Technorati Technorati Twitter What's this?

This article has been cited by other articles:

Zhang, B., Luo, S., Dong, X.-P., Zhang, X., Liu, C., Luo, Z., Xiong, W.-C., Mei, L. (2007). {beta}-Catenin Regulates Acetylcholine Receptor Clustering in Muscle Cells through Interaction with Rapsyn. J. Neurosci. 27: 3968-3973 [Abstract] [Full Text]
Dai, Z., Luo, X., Xie, H., Peng, H. B. (2000). The Actin-Driven Movement and Formation of Acetylcholine Receptor Clusters. JCB 150: 1321-1334 [Abstract] [Full Text]
Cole, J. C, Villa, B. R S, Wilkinson, R. S (2000). Disruption of actin impedes transmitter release in snake motor terminals. J. Physiol. 525: 579-586 [Abstract] [Full Text]
Pumplin, D. (1995). The membrane skeleton of acetylcholine receptor domains in rat myotubes contains antiparallel homodimers of beta-spectrin in filaments quantitatively resembling those of erythrocytes. J. Cell Sci. 108: 3145-3154 [Abstract]
Had, L, Faivre-Sarrailh, C, Legrand, C, Mery, J, Brugidou, J, Rabie, A (1994). Tropomyosin isoforms in rat neurons: the different developmental profiles and distributions of TM-4 and TMBr-3 are consistent with different functions. J. Cell Sci. 107: 2961-2973 [Abstract]
Foltz, K., Partin, J., Lennarz, W. (1993). Sea urchin egg receptor for sperm: sequence similarity of binding domain and hsp70. Science 259: 1421-1425 [Abstract]