The contractile and regulatory proteins of insect flight muscle

Bullard, Belinda; Da̧browska, Renata; Winkelman, L.

doi:10.1042/bj1350277

Cited by 84 publications

(71 citation statements)

References 38 publications

(26 reference statements)

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“…Their studies also demonstrate that this protein is present on the thin filaments of other organisms, namely, the water bug Lethocercus and the brachiopod Glottidia. Similarities in the binding affinity of the 55,000 tool wt protein to actin in the false discharge filament bundle and of a 55,000 mol wt band to actin in Lethocercus muscle is suggested by recent work of Bullard et al (1973).…”

Section: Composition Of the Filament Bundle And The Homology Of Thesementioning

confidence: 87%

Actin filaments in the acrosomal reaction of Limulus sperm. Motion generated by alterations in the packing of the filaments.

Tilney¹

1975

The Journal of Cell Biology

215

109

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When Limulus sperm are induced to undergo the acrosomal reaction, a process, 50 am in length, is generated in a few seconds. This process rotates as it elongates; thus the acrosomal process literally screws through the jelly of the egg. Within the process is a bundle of filaments which before induction are coiled up inside the sperm. The filament bundle exists in three stable states in the sperm. One of the states can be isolated in pure form. It is composed of only three proteins whose molecular weights (mol wt) are 43,000, 55,000, and 95,000. The 43,000 mol wt protein is actin, based on its molecular weight, net charge, morphology, G-F transformation, and heavy meromyosin (HMM) binding. The 55,000 mol wt protein is in equimolar ratio to actin and is not tubulin, binds tenaciously to actin, and inhibits HMM binding. Evidence is presented that both the 55,000 mol wt protein and the 95,000 mol wt protein (possibly a-actinin) are also present in Limulus muscle. Presumably these proteins function in the sperm in holding the actin filaments together. Before the acrosomal reaction, the actin filaments are twisted over one another in a supercoil; when the reaction is completed, the filaments lie parallel to each other and form an actin paracrystal. This change in their packing appears to give rise to the motion of the acrosomal process and is under the control of the 55,000 mol wt protein and the 95,000 mol wt protein.Actin appears to be a ubiquitous protein in both muscle and nonmuscle cells of eucaryotic organisms (see Pollard and Weihing, 1974, for references). Myosin as well has been described in a number of nonmuscle cell types which include the amoeba, fibroblasts, Physarum, and blood platelets. Once one has mentioned the fact that actin and myosin coexist in nonmuscle cells there is almost a "Pavlovian response"--everyone wants to know where the sliding takes place, how long the myosin filaments are, etc. In fact, the sliding filament hypothesis of muscle is so firmly entrenched in our thinking that no other mechanism of motion even comes to mind, or, if it does, it is immediately dismissed as "irrelevant" or as occurring in an "oddball system." This is somewhat surprising as the myosin/actin ratio in most nonmuscle cells is very much less than that present in

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Section: Composition Of the Filament Bundle And The Homology Of Thesementioning

confidence: 87%

Actin filaments in the acrosomal reaction of Limulus sperm. Motion generated by alterations in the packing of the filaments.

Tilney¹

1975

The Journal of Cell Biology

215

109

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“…A protein of similar mol wt (55,000) which can also be distinguished from tubulin has recently been reported by Tilney (36) in the acrosomal process of the horseshoe crab, Limulus polyphemus, where it is also associated with actin. This protein was present in preparations of Limulus leg muscle and had previously been found bound to actin in insect flight muscle (3), where it could be distinguished from tropomyosin and troponin. On the basis of his evidence, Tilney suggests that this protein is attached to the surface of the actin subunits in the acrosomal process, thus accounting for the change in the center-to-center spacing from the 50 A of pure actin to the 85 /~ measured in the acrosomal process and also for the absence of heavy meromyosin binding to the actin in the presence of the 55,000 tool wt protein.…”

Section: Discussionmentioning

confidence: 99%

Preparation and purification of polymerized actin from sea urchin egg extracts.

Kane¹

1975

The Journal of Cell Biology

219

145

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Isotonic extracts of the soluble cytoplasmic proteins of sea urchin eggs, containing sufficient EGTA to reduce the calcium concentration to low levels, form a dense gel on warming to 35 40~ Although this procedure is similar to that used to polymerize tubulin from mammalian brain, sodium dodecyl sulfate-polyacrylamide gel electrophoresis shows this gel to have actin as a major component and to contain no tubulin. If such extracts are dialyzed against dilute salt solution, they no longer respond to warming, but gelation will occur if they are supplemented with 1 mM ATP and 0.020 M KC1 before heating. Gelation is not temperature reversible, but the gelled material can be dissolved in 0.6-1 M J~C1 and these solutions contain F-actin filaments. These filaments slowly aggregate to microscopic, birefringent fibrils when l mM ATP is added to the solution, and this procedure provides a simple method for preparing purified actin. The supernate remaining after actin removal contains the other two components of the gel, proteins of approximately 58,000 and 220,000 mol wt. These two proteins plus actin recombine to form the original gel material when the ionic strength is reduced. This reaction is reversible at 0~ and no heating is required.Following the demonstration of an actin-like protein, similar in properties to muscle actin, in myxomycete plasmodium (9, 10), similar methods revealed the presence of a cytoplasmic actin in unfertilized sea urchin eggs. This sea urchin egg actin was first identified and separated through its combination with rabbit muscle myosin (8,18,19), and the protein was later prepared directly from egg extracts by salting out with ammonium sulfate (17). These preparative methods gave no information concerning the localization of the actin within the egg, but there is good evidence lor its presence in the cleavage furrow during cytokinesis, where it was seen first in the electron microscope as bundles of microfilaments (28,30,37). Actin has been localized in the cleavage furrow in a variety of other cell types ( 1,21,27,29,34) and this actin has been specifically labeled with heavy meromyosin (31). The investigations reported here were begun with the aim of determining whether the methods developed for the polymerization of tubulin to microtubules in mammalian brain (2, 39) could be used to prepare tubulin from the sea urchin egg. Marine eggs are an excellent source of isolated mitotic apparatuses for the investigation of the role of microtubules in chromosome movement, but up to this time only the interaction of mammalian brain tuhulin with such isolated mitotic apparatuses has been reported (12, 25). Our attempts to prepare tubulin from extracts of sea urchin eggs with the methods developed for mammalian material were unsuccessful, and a number of modifications of this method were made to adapt it to the

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“…Lethocerus troponin T and troponin H (with Lethocerus tropomyosin) inhibit rabbit actomysoin, and rabbit troponin C relieves the inhibition if Ca ++ is present (Bullard et al, 1973a). Troponin H, although it replaces troponin I in asynchronous flight muscle, does not inhibit rabbit actomyosin ATPase activity (Bullard et al, 1988).…”

Section: Ecdysozoamentioning

confidence: 99%

Invertebrate muscles: Thin and thick filament structure; molecular basis of contraction and its regulation, catch and asynchronous muscle

Hooper

Hobbs

Thuma

2008

Progress in Neurobiology

128

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This is the second in a series of canonical reviews on invertebrate muscle. We cover here thin and thick filament structure, the molecular basis of force generation and its regulation, and two special properties of some invertebrate muscle, catch and asynchronous muscle. Invertebrate thin filaments resemble vertebrate thin filaments, although helix structure and tropomyosin arrangement show small differences. Invertebrate thick filaments, alternatively, are very different from vertebrate striated thick filaments and show great variation within invertebrates. Part of this diversity stems from variation in paramyosin content, which is greatly increased in very large diameter invertebrate thick filaments. Other of it arises from relatively small changes in filament backbone structure, which results in filaments with grossly similar myosin head placements (rotating crowns of heads every 14.5 nm) but large changes in detail (distances between heads in azimuthal registration varying from three to thousands of crowns). The lever arm basis of force generation is common to both vetebrates and invertebrates, and in some invertebrates this process is understood on the near atomic level. Invertebrate actomyosin is both thin (tropomyosin:troponin) and thick (primarily via direct Ca ++ binding to myosin) filament regulated, and most invertebrate muscles are dually regulated. These mechanisms are well understood on the molecular level, but the behavioral utility of dual regulation is less so. The phosphorylation state of the thick filament associated giant protein, twitchin, has been recently shown to be the molecular basis of catch. The molecular basis of the stretch activation underlying asynchronous muscle activity, however, remains unresolved.

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The contractile and regulatory proteins of insect flight muscle

Cited by 84 publications

References 38 publications

Actin filaments in the acrosomal reaction of Limulus sperm. Motion generated by alterations in the packing of the filaments.

Actin filaments in the acrosomal reaction of Limulus sperm. Motion generated by alterations in the packing of the filaments.

Preparation and purification of polymerized actin from sea urchin egg extracts.

Invertebrate muscles: Thin and thick filament structure; molecular basis of contraction and its regulation, catch and asynchronous muscle

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