Presence of tailed, asymmetric forms of acetylcholinesterase in the central nervous system of vertebrates

Rieger, François; Chételat, Roger; Nicolet, M.‐A.; Kamal, L A; Poullet, Monique

doi:10.1016/0014-5793(80)81290-7

Cited by 33 publications

(5 citation statements)

References 32 publications

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“…In contrast, the optic lobe contains almost exclusively M AChE; this is similar to other reports of AChE forms in chick brain (Marchand et al, 1977;Andersen and Mikalsen, 1978) and rat brain (Rieger and Vigny, 1976). In the chick optic lobe, a trace of 20s AChE has been recently detected using essentially the same extraction medium as employed here but with extended reaction periods in the enzyme analysis (Rieger et al, 1980) or using collagenase digestion of the residue (Villafruela et al, 1981). The levels (-0.2%) are such as to be entirely consistent with its absence under our conditions.…”

supporting

confidence: 89%

Comparison of the Molecular Forms of the Cholinesterases in Tissues of Normal and Dystrophic Chickens

Lyles

Silman

Giamberardino

et al. 1982

Journal of Neurochemistry

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The levels and molecular forms of acetylcholinesterase (AChE, EC 3.1.1.7) and pseudocholinesterase (psiChE, EC 3.1.1.8) were examined in various skeletal muscles, cardiac muscles, and neural tissues from normal and dystrophic chickens. The relative amount of the heavy (Hc) form of AChE in mixed-fibre-type twitch muscles varies in proportion to the percentage of glycolytic fast-twitch fibres. Conversely, muscles with higher levels of oxidative fibres (i.e., slow-tonic oxidative-glycolytic fast-twitch, or oxidative slow-twitch) have higher proportions of the light (L) form of AChE. The effects of dystrophy on AChE and psiChE are more severe in muscles richer in glycolytic fast-twitch fibres (e.g., pectoral or posterior latissimus dorsi, PLD); there is no alteration of AChE or psiChE in a slow-tonic muscle. In the pectoral of PLD muscles from older dystrophic chickens, however, the AChE forms revert to a normal distribution while the pesChE pattern remains abnormal. Muscle psiChE is sensitive to collagenase in a similar way as is AChE, thus apparently having a similar tailed structure. Unlike skeletal muscle, cardiac muscle has very high levels of psiChE, present mainly as the L form; AChE is present mainly as the medium (M) form, with smaller amounts of L and Hc. The latter pattern of AChE forms resembles that seen in several neural tissues examined. No alterations in AChE or psiChE were found in cardiac or neural tissues from dystrophic chickens.

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supporting

confidence: 89%

Comparison of the Molecular Forms of the Cholinesterases in Tissues of Normal and Dystrophic Chickens

Lyles

Silman

Giamberardino

et al. 1982

Journal of Neurochemistry

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“…In addition, collagen-tailed forms have previously been shown to exist in saline extracts of SCG . The "heavy" form has also been found, in very small proportion, in the brains of mouse and rat (Rieger et al, 1980), but not in the caudate nucleus. However, we have detected the A,, and A, collagen-tailed forms in the bovine caudate nucleus, where they amount to only about 0.002% of the total activity.…”

Section: Discussionmentioning

confidence: 95%

“…They occur in significant proportions in the brains of fishes, amphibians, and reptiles (Massoulie et al, 1980). Collagen-tailed forms have also recently been shown to exist in trace amounts in the CNS of chicken (Villafruela et al, 1980, rat, and mouse (Rieger et al, 1980). The globular forms are generally predominant in mammalian tissues, particularly in the brain.…”

mentioning

confidence: 99%

Molecular Forms of Acetylcholinesterase in Bovine Caudate Nucleus and Superior Cervical Ganglion: Solubility Properties and Hydrophobic Character

Grassi

Vigny

Massoulié

1982

Journal of Neurochemistry

103

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In the present paper, we report an analysis of acetylcholinesterase molecular forms in the bovine caudate nucleus and superior cervical ganglion. We show that: (1) The superior cervical ganglion contains a significant proportion (∼ 15%) of collagen‐tailed forms (mostly A12 and A8), but these molecules are found only as traces (ca. 0.002%) in the caudate nucleus, even in favorable extraction conditions (i.e., in the presence of 1 m‐NaCl, 5 mm‐EDTA, 1% Triton X‐100). (2) The bulk of acetylcholinesterase corresponds to globular forms, mostly the tetrameric G4 and the monomeric G1 forms, with a smaller proportion of the dimeric G2 form. (3) The tetrameric enzyme exists as a minor soluble component (GS4) that does not interact with Triton X‐100, and a major hydrophobic component (GH4) that is partially solubilized in the absence of detergent in the caudate nucleus, but not in the superior cervical ganglion. (4) The monomeric G1 form presents a marked hydrophobic character, as indicated by its interaction with Triton X‐100, although it may be solubilized in large part in the absence of detergent in both tissues. (5) The detergentsolubilized forms aggregate upon removal of detergent. This property disappears after partial purification of G4) that does not interact with Triton X‐100, and a major hydrophobic component (GH4, but is restored upon addition of an inactivated crude extract, indicating that it is attributable to interactions with other hydrophobic components. (6) The proportions of molecular forms solubilized in detergent‐free buffers vary with the ionic composition of the medium. Repeated extractions of caudate nucleus in Tris‐HCl buffer produce a larger overall yield of G1 form (e.g., 40%) than appears in a single quantitative detergent solubilization (<15%). This G1 form apparently derives in part from a pool of GH4 form. (7) However, detergents that allow a quantitative solubilization of acetylcholinesterase yield the same proportions of forms (about 85% G4) independently of the ionic conditions. (8) Modifications of the molecular forms occur spontaneously during purification, or storage of the crude aqueous ex‐tracts, in a manner that depends on the ionic conditions. In Tris‐HCl buffer, G1 is converted into a well‐defined 7.5S form. In Ringer, polydisperse components are formed. The effects observed in Ringer cannot be reproduced by addition of 5 mm‐Ca2‐ to the Tris buffer either during or after extraction. (9) Proteases, such as pronase, convert the hydrophobic forms into molecules that do not appear to interact with Triton X‐100, and do not aggregate in its absence. These results raise fundamental questions regarding the status of acetylcholinesterase in situ, the structure and interactions of its molecular forms. They are discussed with reference to previous publications.

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“…Immature rat or chick muscle cells, at least in culture, possess a capacity to synthesize and accumulate the asymmetric molecular forms of AChE even in the absence of nerves [Sugiyama, 1977;Rieger et al, 1980;Bulger et al, 1982;Silberstein et al, 19821. However, in vivo those forms eventually appear in developing muscles concomitantly with innervation [Vigny et al 1976;Koenig and Vigny, 19781.…”

Section: Discussionmentioning

confidence: 99%

Asymmetric molecular forms of acetylcholinesterase in mammalian skeletal muscles

Sketelj

Brzin

1985

J of Neuroscience Research

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Velocity sedimentation analysis of acetylcholinesterase (AChE) molecular forms was performed separately in endplate-rich and endplate-free regions of the diaphragm muscle of the rat, guinea pig, rabbit, dog, and pig, and in mm. erectores trunci and m. vastus lateralis in man. Several high-ionic-strength media were first tested to achieve better solubilization of AChE from rat muscles than by the usual 1 M NaCl-Triton X-100 medium. Ninety-five percent of the AChE from the motor endplate region of the rat diaphragm was solubilized in a single extraction step by medium containing 1 M lithium chloride instead of NaCl. Homologous molecular forms of AChE were found in all species. The asymmetric forms were invariably present in the endplate regions of muscles but their activity in endplate-free regions was much lower than in endplate regions in all investigated mammals except in man. Essentially the same pattern of AChE molecular forms was present in both regions in human muscles. High extrajunctional activity of the asymmetric forms makes human muscles similar to immature rodent muscles in vivo and in culture. The pattern of AChE molecular forms in the endplate region of the diaphragm in senile 24-month-old rats was not significantly different from that in 3-month-old animals. The persistence of the asymmetric AChE forms in the diaphragm of senile rats suggests that neuromuscular interactions do not become deficient with age in this muscle.

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Presence of tailed, asymmetric forms of acetylcholinesterase in the central nervous system of vertebrates

Cited by 33 publications

References 32 publications

Comparison of the Molecular Forms of the Cholinesterases in Tissues of Normal and Dystrophic Chickens

Comparison of the Molecular Forms of the Cholinesterases in Tissues of Normal and Dystrophic Chickens

Molecular Forms of Acetylcholinesterase in Bovine Caudate Nucleus and Superior Cervical Ganglion: Solubility Properties and Hydrophobic Character

Asymmetric molecular forms of acetylcholinesterase in mammalian skeletal muscles

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