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Acetylcholinesterase in Cocultures of Rat Myotubes and Spinal Cord Neurons: Effects of Collagenase and cis ‐Hydroxyproline on Molecular Forms, Intra‐ and Extracellular Distribution, and Formation of Patches at Neuromuscular Contacts
Author(s) -
Vallette FrançoisMarie,
De la Porte Sabine,
Koenig Jeanine,
Massoulié Jean,
Vigny Marc
Publication year - 1990
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1111/j.1471-4159.1990.tb02338.x
Subject(s) - acetylcholinesterase , myogenesis , collagenase , extracellular , aché , intracellular , acetylcholine , neuromuscular junction , biology , spinal cord , biochemistry , microbiology and biotechnology , anatomy , chemistry , myocyte , endocrinology , enzyme , neuroscience
Cultures of rat myotubes from 18‐day‐old embryos produce both globular (G) and asymmetric (A) forms of acetylcholinesterase (AChE; EC 3.1.1.7), mostly G 1 , G 4 , and A 12 and a small proportion of A 8 . We show that all forms are partly intracellular and partly exposed to the extracellular medium; the A forms and their intra‐ and extracellular distribution are not modified when myotubes are grown in the presence of spinal cord neurons. In these cocultures, however, AChE patches may be detected immunohistochemically at sites of neuromuscular contacts. These patches represent a very minor proportion of AChE activity. We found that collagenase removes AChE patches but not the acetylcholine receptor clusters with which they coincide. This digestion specifically decreases the level of the A 12 form. cis ‐Hydroxyproline, an inhibitor of collagen synthesis, reduces the level of G 1 and blocks the synthesis of A forms.