Abstract
The aim of this study was to characterize the molecular forms of acetylcholinesterase (AChE) associated with the synaptic basal lamina at the neuromuscular junction. The observations were made on the neuromuscular junctions of cutaneous pectoris muscles of frog, Rana pipiens, which are similar to junctions of most other vertebrates including mammals, but are especially convenient for experimentation. By measuring relative AChE activity in junctional and extrajunctional regions of muscles after selective inactivation of extracellular AChE with echothiophate, or of intracellular AChE with DFP and 2-PAM, we found that > 66% of the total AChE activity in the muscle was junction- specific, and that > 50% of the junction-specific AChE was on the cell surface. More than 80% of the cell surface AChE was solubilized in high ionic strength detergent-free buffer, indicating that most, if not all, was a component of the synaptic basal lamina. Sedimentation analysis of that fraction indicated that while asymmetric forms (A12, A8) were abundant, globular forms sedimenting at 4-6 S (G1 and G2), composed > 50% of the AChE. It was also found that when muscles were damaged in various ways that caused degeneration of axons and muscle fibers but left intact the basal lamina sheaths, the small globular forms persisted at the synaptic site for weeks after phagocytosis of cellular components; under certain damage conditions, the proportion of globular to asymmetric forms in the vacated basal lamina sheaths was as in normal junctions. While the asymmetric forms required high ionic strength for solubilization, the extracellular globular AChE could be extracted from the junctional regions of normal and damaged muscles by isotonic buffer. Some of the globular AChE appeared to be amphiphilic when examined in detergents, suggesting that it may form hydrophobic interactions, but most was non-amphiphilic consistent with the possibility that it forms weak electrostatic interactions. We conclude that the major form of AChE in frog synaptic basal lamina is globular and that its mode of association with the basal lamina differs from that of the asymmetric forms.
Full Text
The Full Text of this article is available as a PDF (3.6 MB).
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- AUSTIN L., BERRY W. K. Two selective inhibitors of cholinesterase. Biochem J. 1953 Jul;54(4):695–700. [PMC free article] [PubMed] [Google Scholar]
- Anglister L. Acetylcholinesterase from the motor nerve terminal accumulates on the synaptic basal lamina of the myofiber. J Cell Biol. 1991 Nov;115(3):755–764. doi: 10.1083/jcb.115.3.755. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Anglister L., McMahan U. J. Basal lamina directs acetylcholinesterase accumulation at synaptic sites in regenerating muscle. J Cell Biol. 1985 Sep;101(3):735–743. doi: 10.1083/jcb.101.3.735. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Anglister L., McMahan U. J. Extracellular matrix components involved in neuromuscular transmission and regeneration. Ciba Found Symp. 1984;108:163–178. doi: 10.1002/9780470720899.ch11. [DOI] [PubMed] [Google Scholar]
- Anglister L., Silman I. Molecular structure of elongated forms of electric eel acetylcholinesterase. J Mol Biol. 1978 Nov 5;125(3):293–311. doi: 10.1016/0022-2836(78)90404-7. [DOI] [PubMed] [Google Scholar]
- Bon S., Cartaud J., Massoulié J. The dependence of acetylcholinesterase aggregation at low ionic strength upon a polyanionic component. Eur J Biochem. 1978 Apr;85(1):1–14. doi: 10.1111/j.1432-1033.1978.tb12207.x. [DOI] [PubMed] [Google Scholar]
- Bon S., Massoulié J. Collagenase sensitivity and aggregation properties of Electrophorus acetylcholinesterase. Eur J Biochem. 1978 Aug 15;89(1):89–94. doi: 10.1111/j.1432-1033.1978.tb20899.x. [DOI] [PubMed] [Google Scholar]
- Bon S., Rieger F., Massoulié J. Propriétés des formes allongées de l'acétylcholinestérase en solution. Rayon de Stokes, densité et masse. Eur J Biochem. 1973 Jun;35(2):372–379. doi: 10.1111/j.1432-1033.1973.tb02849.x. [DOI] [PubMed] [Google Scholar]
- Bon S., Toutant J. P., Méflah K., Massoulié J. Amphiphilic and nonamphiphilic forms of Torpedo cholinesterases: I. Solubility and aggregation properties. J Neurochem. 1988 Sep;51(3):776–785. doi: 10.1111/j.1471-4159.1988.tb01812.x. [DOI] [PubMed] [Google Scholar]
- Bon S., Vigny M., Massoulié J. Asymmetric and globular forms of acetylcholinesterase in mammals and birds. Proc Natl Acad Sci U S A. 1979 Jun;76(6):2546–2550. doi: 10.1073/pnas.76.6.2546. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Bordier C. Phase separation of integral membrane proteins in Triton X-114 solution. J Biol Chem. 1981 Feb 25;256(4):1604–1607. [PubMed] [Google Scholar]
- Bradford M. M. A rapid and sensitive method for the quantitation of microgram quantities of protein utilizing the principle of protein-dye binding. Anal Biochem. 1976 May 7;72:248–254. doi: 10.1006/abio.1976.9999. [DOI] [PubMed] [Google Scholar]
- Brandan E., Inestrosa N. C. Binding of the asymmetric forms of acetylcholinesterase to heparin. Biochem J. 1984 Jul 15;221(2):415–422. doi: 10.1042/bj2210415. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Carson S., Bon S., Vigny M., Massoulié J., Fardeau M. Distribution of acetylcholinesterase molecular forms in neural and non-neural sections of human muscle. FEBS Lett. 1979 Jan 15;97(2):348–352. doi: 10.1016/0014-5793(79)80119-2. [DOI] [PubMed] [Google Scholar]
- Eichler J., Silman I., Anglister L. G2-acetylcholinesterase is presynaptically localized in Torpedo electric organ. J Neurocytol. 1992 Oct;21(10):707–716. doi: 10.1007/BF01181586. [DOI] [PubMed] [Google Scholar]
- Etges R., Bouvier J., Bordier C. The major surface protein of Leishmania promastigotes is anchored in the membrane by a myristic acid-labeled phospholipid. EMBO J. 1986 Mar;5(3):597–601. doi: 10.1002/j.1460-2075.1986.tb04252.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Fernandez H. L., Inestrosa N. C., Stiles J. R. Subcellular localization of acetylcholinesterase molecular forms in endplate regions of adult mammalian skeletal muscle. Neurochem Res. 1984 Sep;9(9):1211–1230. doi: 10.1007/BF00973035. [DOI] [PubMed] [Google Scholar]
- Futerman A. H., Fiorini R. M., Roth E., Low M. G., Silman I. Physicochemical behaviour and structural characteristics of membrane-bound acetylcholinesterase from Torpedo electric organ. Effect of phosphatidylinositol-specific phospholipase C. Biochem J. 1985 Mar 1;226(2):369–377. doi: 10.1042/bj2260369. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Grassi J., Massoulié J., Timpl R. Relationship of collagen-tailed acetylcholinesterase with basal lamina components. Absence of binding with laminin, fibronectin, and collagen types IV and V and lack of reactivity with different anti-collagen sera. Eur J Biochem. 1983 Jun 1;133(1):31–38. doi: 10.1111/j.1432-1033.1983.tb07426.x. [DOI] [PubMed] [Google Scholar]
- Gulati A. K., Reddi A. H., Zalewski A. A. Changes in the basement membrane zone components during skeletal muscle fiber degeneration and regeneration. J Cell Biol. 1983 Oct;97(4):957–962. doi: 10.1083/jcb.97.4.957. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hall Z. W. Multiple forms of acetylcholinesterase and their distribution in endplate and non-endplate regions of rat diaphragm muscle. J Neurobiol. 1973;4(4):343–361. doi: 10.1002/neu.480040404. [DOI] [PubMed] [Google Scholar]
- Jedrzejczyk J., Silman I., Lai J., Barnard E. A. Molecular forms of acetylcholinesterase in synaptic and extrasynaptic regions of avian tonic muscle. Neurosci Lett. 1984 May 18;46(3):283–289. doi: 10.1016/0304-3940(84)90113-7. [DOI] [PubMed] [Google Scholar]
- Johnson C. D., Russell R. L. A rapid, simple radiometric assay for cholinesterase, suitable for multiple determinations. Anal Biochem. 1975 Mar;64(1):229–238. doi: 10.1016/0003-2697(75)90423-6. [DOI] [PubMed] [Google Scholar]
- Johnson C. D., Smith S. P., Russell R. L. Electrophorus electricus acetylcholinesterases; separation and selective modification by collagenase. J Neurochem. 1977 Mar;28(3):617–624. doi: 10.1111/j.1471-4159.1977.tb10433.x. [DOI] [PubMed] [Google Scholar]
- KARNOVSKY M. J. THE LOCALIZATION OF CHOLINESTERASE ACTIVITY IN RAT CARDIAC MUSCLE BY ELECTRON MICROSCOPY. J Cell Biol. 1964 Nov;23:217–232. doi: 10.1083/jcb.23.2.217. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Lazar M., Vigny M. Modulation of the distribution of acetylcholinesterase molecular forms in a murine neuroblastoma x sympathetic ganglion cell hybrid cell line. J Neurochem. 1980 Nov;35(5):1067–1079. doi: 10.1111/j.1471-4159.1980.tb07860.x. [DOI] [PubMed] [Google Scholar]
- MARTIN R. G., AMES B. N. A method for determining the sedimentation behavior of enzymes: application to protein mixtures. J Biol Chem. 1961 May;236:1372–1379. [PubMed] [Google Scholar]
- Massoulié J., Bon S. The molecular forms of cholinesterase and acetylcholinesterase in vertebrates. Annu Rev Neurosci. 1982;5:57–106. doi: 10.1146/annurev.ne.05.030182.000421. [DOI] [PubMed] [Google Scholar]
- Massoulié J., Pezzementi L., Bon S., Krejci E., Vallette F. M. Molecular and cellular biology of cholinesterases. Prog Neurobiol. 1993 Jul;41(1):31–91. doi: 10.1016/0301-0082(93)90040-y. [DOI] [PubMed] [Google Scholar]
- McISAAC R. J., KOELLE G. B. Comparison of the effects of inhibition of external, internal and total acetylcholinesterase upon ganglionic transmission. J Pharmacol Exp Ther. 1959 May;126(1):9–20. [PubMed] [Google Scholar]
- McMahan U. J., Sanes J. R., Marshall L. M. Cholinesterase is associated with the basal lamina at the neuromuscular junction. Nature. 1978 Jan 12;271(5641):172–174. doi: 10.1038/271172a0. [DOI] [PubMed] [Google Scholar]
- McMahan U. J., Slater C. R. The influence of basal lamina on the accumulation of acetylcholine receptors at synaptic sites in regenerating muscle. J Cell Biol. 1984 Apr;98(4):1453–1473. doi: 10.1083/jcb.98.4.1453. [DOI] [PMC free article] [PubMed] [Google Scholar]
- McMahan U. J., Wallace B. G. Molecules in basal lamina that direct the formation of synaptic specializations at neuromuscular junctions. Dev Neurosci. 1989;11(4-5):227–247. doi: 10.1159/000111903. [DOI] [PubMed] [Google Scholar]
- Nicolet M., Pinçon-Raymond M., Rieger F. Globular and asymmetric acetylcholinesterase in frog muscle basal lamina sheaths. J Cell Biol. 1986 Mar;102(3):762–768. doi: 10.1083/jcb.102.3.762. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Nicolet M., Rieger F. Ubiquitous presence of the tailed, asymmetric forms of acetylcholinesterase in the peripheral and central nervous systems of the frog (Rana temporaria). Neurosci Lett. 1982 Jan 22;28(1):67–73. doi: 10.1016/0304-3940(82)90210-5. [DOI] [PubMed] [Google Scholar]
- Ramírez G., Barat A., Fernández H. L. Interaction of asymmetric and globular acetylcholinesterase species with glycosaminoglycans. J Neurochem. 1990 May;54(5):1761–1768. doi: 10.1111/j.1471-4159.1990.tb01231.x. [DOI] [PubMed] [Google Scholar]
- Sanes J. R. Laminin, fibronectin, and collagen in synaptic and extrasynaptic portions of muscle fiber basement membrane. J Cell Biol. 1982 May;93(2):442–451. doi: 10.1083/jcb.93.2.442. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Sanes J. R., Marshall L. M., McMahan U. J. Reinnervation of muscle fiber basal lamina after removal of myofibers. Differentiation of regenerating axons at original synaptic sites. J Cell Biol. 1978 Jul;78(1):176–198. doi: 10.1083/jcb.78.1.176. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Silman I., Futerman A. H. Modes of attachment of acetylcholinesterase to the surface membrane. Eur J Biochem. 1987 Dec 30;170(1-2):11–22. doi: 10.1111/j.1432-1033.1987.tb13662.x. [DOI] [PubMed] [Google Scholar]
- Silman I., Lyles J. M., Barnard E. A. Intrinsic forms of acetylcholinesterase in skeletal muscle. FEBS Lett. 1978 Oct 1;94(1):166–170. doi: 10.1016/0014-5793(78)80929-6. [DOI] [PubMed] [Google Scholar]
- Timpl R., Dziadek M. Structure, development, and molecular pathology of basement membranes. Int Rev Exp Pathol. 1986;29:1–112. [PubMed] [Google Scholar]
- Vigny M., Koenig J., Rieger F. The motor end-plate specific form of acetylcholinesterase: appearance during embryogenesis and re-innervation of rat muscle. J Neurochem. 1976 Dec;27(6):1347–1353. doi: 10.1111/j.1471-4159.1976.tb02614.x. [DOI] [PubMed] [Google Scholar]
- Vigny M., Martin G. R., Grotendorst G. R. Interactions of asymmetric forms of acetylcholinesterase with basement membrane components. J Biol Chem. 1983 Jul 25;258(14):8794–8798. [PubMed] [Google Scholar]
- Weinberg C. B., Hall Z. W. Junctional form of acetylcholinesterase restored at nerve-free endplates. Dev Biol. 1979 Feb;68(2):631–635. doi: 10.1016/0012-1606(79)90233-1. [DOI] [PubMed] [Google Scholar]
- Younkin S. G., Rosenstein C., Collins P. L., Rosenberry T. L. Cellular localization of the molecular forms of acetylcholinesterase in rat diaphragm. J Biol Chem. 1982 Nov 25;257(22):13630–13637. [PubMed] [Google Scholar]