Neural Regulation of Properties of the Nicotinic Acetylcholine Receptor

Rubin, Lee L.; Anthony, Donna T.; Englander, Libbe L.; Middleton, Pamela; Schuetze, Stephen M.

doi:10.3109/10799898809048985

Cited by 5 publications

(1 citation statement)

References 25 publications

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“…We and others have found the 43-kD AChR-associated protein and a nonmuscle form of actin to be concentrated in the vicinity of AChR clusters and in the postsynaptic region of the adult neuromuscular junction (5,8,21,42,47). Our previous work showed that the initial formation of AChR clusters, but not the integrity of existing clusters, is disrupted by cytochalasin treatment (17).…”

Section: Tropomyosin 2 May Function As Part Of a Sub-cluster Cytoskelmentioning

confidence: 93%

A molecular defect in virally transformed muscle cells that cannot cluster acetylcholine receptors.

Anthony

Jacobs-Cohen

Marazzi

et al. 1988

The Journal of Cell Biology

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Abstract. Muscle cells infected at the permissive temperature with temperature-sensitive mutants of Rous sarcoma virus and shifted to the non-permissive temperature form myotubes that are unable to cluster acetylcholine receptors (Anthony, D. T., S. M. Schuetze, and L. L. Rubin. 1984. Proc. Natl. Acad. Sci. USA. 81:2265-2269.). Work described in this paper demonstrates that the vitally-infected cells are missing a 37-kD peptide which reacts with an anti-tropomyosin antiserum. Using a monoclonal antibody specific for the missing peptide, we show that this tropomyosin is absent from fibroblasts and is distinct from smooth muscle tropomyosins. It is also different from the two previously identified striated muscle myofibrillar tropomyosins (alpha and beta). We suggest that, in normal muscle, this novel, non-myofibrillar, tropomyosin-like molecule is an important component of a cytoskeletal network necessary for cluster formation. characteristic feature of the vertebrate neuromuscular junction is its enormously high concentration of acetylcholine receptors (AChRs) I. AChRs are uniformly distributed along embryonic muscle fibers, but accumulate at high concentrations at junctional sites in response to innervation. This accumulation is probably initiated by a factor of neural origin (12,28,43). In mature muscle, clusters are maintained by a component of the muscle's basal lamina, which has been studied in some detail (11,39). How the muscle cell responds to molecules that induce clustering is not well understood, although it might be anticipated that cytoskeletal elements are involved. A variety of cytoskeletal molecules are present in either the postsynaptic region of adult muscle or beneath AChR clusters on cultured muscle cells. These include alpha-actinin, filamin, vinculin, talin, an intermediate filament-like molecule, nonmuscle actin, a 300-kD protein, and a 58-kD protein (5-7, 19, 22, 23, 33, 47, 49, 56; reviewed in reference 20). In addition, a 43-kD AChR-associated protein, thought to be capable of binding to both the AChR (10) and actin (53), is concentrated near AChR clusters (8,21,42,46,50).The mere presence of a cytoskeletal molecule, however, does not guarantee its participation in clustering. Other structural changes occur during muscle cell development that could also require cytoskeletal reorganization. For instance, the synaptic region of muscle is characterized by extensive membrane folds. In addition, we have shown that AChR clustering initiates the sub-membrane localization and immobilization of a set of myonuclei and Golgi apparatus. This process probably results from a cytoskeletal reorganiza- tion beneath the cluster (17). To establish that particular cytoskeletal molecules have a direct role in clustering, evidence of a more functional nature must be obtained.Previously, we reported that chick myotubes that are infected at the permissive temperature with a temperaturesensitive mutant (tsNY68) of Rous sarcoma virus (RSV) and allowed to fuse at the nonpermissive temperature do not cluster thei...

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Section: Tropomyosin 2 May Function As Part Of a Sub-cluster Cytoskelmentioning

confidence: 93%

A molecular defect in virally transformed muscle cells that cannot cluster acetylcholine receptors.

Anthony

Jacobs-Cohen

Marazzi

et al. 1988

The Journal of Cell Biology

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Desensitization of central cholinergic mechanisms and neuroadaptation to nicotine

Ochoa

McNamee

1990

Mol Neurobiol

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This review focuses on neuroadaptation to nicotine. The first part of the paper delineates some possible general mechanisms subserving neuroadaptation to commonly abused drugs. The postulated role of the mesocorticolimbic neuroanatomical pathway and drug-receptor desensitization mechanisms in the establishment of tolerance to, dependence on, and withdrawal from psychoactive drugs are discussed. The second part of the review deals with the pharmacological effects of nicotine at both pre- and postsynaptic locations within the central nervous system, and the still-perplexing upregulation of brain nicotine-binding sites seen after chronic nicotine administration. A special emphasis has been put on desensitization of presynaptic cholinergic mechanisms, and postsynaptic neuronal nicotinic-receptor function and its modulation by endogenous substances. A comparison with the inactivation process occurring at peripheral nicotinic receptors is also included. Finally, a hypothesis on the possible connections between desensitization of central cholinergic mechanisms and neuroadaptation to nicotine is advanced. A brief comment on the necessity of fully understanding the effects of nicotine on the developing nervous system closes this work.

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Stephen M. Schuetze (1951–1987)

Chalfie

Siegelbaum

1988

Trends in Neurosciences

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Neural Regulation of Properties of the Nicotinic Acetylcholine Receptor

Cited by 5 publications

References 25 publications

A molecular defect in virally transformed muscle cells that cannot cluster acetylcholine receptors.

A molecular defect in virally transformed muscle cells that cannot cluster acetylcholine receptors.

Desensitization of central cholinergic mechanisms and neuroadaptation to nicotine

Stephen M. Schuetze (1951–1987)

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