Domains, motions and regulation in the myosin head

Vibert, Peter; Cohen, Carolyn

doi:10.1007/bf01773873

Cited by 93 publications

(51 citation statements)

References 122 publications

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“…A number of studies (see reviews by Mornet et al, 1989;Vibert and Cohen, 1988) have illustrated the complexity and the extent of the interface between the myosin head and Factin. Several sites and contact points were detected on subdomain-1 of actin-filament subunits.…”

Section: Discussionmentioning

confidence: 99%

Localization of two myosin‐subfragment‐1 binding contacts in the 96–132 region of actin subdomain‐1

Labbé

Boyer

Méjea

et al. 1993

European Journal of Biochemistry

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Many direct observations and indirect experimental approaches have pin-pointed two segments (sequences 1-28 and 360-372) in actin subdomain-1 which bind to myosin subfragment-1. In a previous investigation [Labbt, J. P., Mtjean, C., Benyamin, Y. & Roustan, C. (1990) Biochem. J. 271, 407-4131, we have observed competition between myosin subfragment-1 and anti-actin antibodies specific to epitopes including Thrl03. A multisite interface model has also been proposed to take into account myosin-head binding to the N-terminal and C-terminal regions and to more central 40 -11 3 sequence of actin.In the present study, two limited actin segments encompassing residues 96-103 and 112-125 were identified as myosin-head-binding sites. The in vitro inhibitory effect of filamin on actin-activated Mg*+-ATPase would thus be explained by this competition. Furthermore, the (27-ma-50-kDa-20-kDa) trypsin-split myosin subfragment-1 which could no longer be activated by actin, did not bind at all to the two sites located in the 96-125 region, but it still interacted with the 360-372 segment.Our results regarding the position of the myosin head on actin monomers in rigor conditions provide evidence on the presence of two topologically independant contact points in the myosinheaaactin interface. One group exposed residues in the 1-7, 21-29, 77-95 and 96-103 actin segment, another, on the opposite side of subdomain-1. included residues from 112-125 and 360-372 sequences.Identification of the actidmyosin interface is essential in understanding the cyclical enzymic and mechanical process of myofibrillar contraction. Several indirect experimental approaches such as chemical cross-linking (Sutoh, 1982), NMR Correspondence to

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Section: Discussionmentioning

confidence: 99%

Localization of two myosin‐subfragment‐1 binding contacts in the 96–132 region of actin subdomain‐1

Labbé

Boyer

Méjea

et al. 1993

European Journal of Biochemistry

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“…The binding of ATP, which occurs on portions of the 25 and 50 kDa peptides [10], is believed to promote relative movements of these actin domains affecting the actin-myosin interactions; and vice versa, the attachment of actin modulates the conformation of the ATPase domains [11]. Thus, inter-domain motions in S-1 should determine the large-scale motions of the myosin heads during muscle activity [12,13]. Recently, direct visualization of the domain structure of S-1 was approached by electron microscopy, showing the head to contain a major cleft that divides the protein into a large, distal domain and two smaller regions linked to the headtail junction of myosin; the mass of the former domain may accommodate the NHE-terminal 75 kDa heavy chain segment with the 50 kDa-20 kDa junction possibly very close to this cleft [14,15].…”

Section: Introductionmentioning

confidence: 99%

Selective cleavage at lysine of the 50 kDa‐20 kDa connector loop segment of skeletal myosin S‐1 by endoproteinase Arg‐C

1989

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The reaction of endoproteinase Arg-C on the skeletal myosin head heavy chain was investigated through characterization of peptides and amino acid sequence analysis. The protease splits exclusively the 50 kDa-20 kDa junction at the lysine cluster spanning residues 639~i41 and does not affect any other protease-sensitive region of the entire myosin heavy chain. The sensitivity of the cleavage to actin and nucleotide binding makes this protease a very specific conformational probe of S-1. The nicked S-1 derivative, containing an intact NH2-terminal 75 kDa fragment, may serve as a tool for gaining further insights into the domain structure and function of the myosin head.

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“…In the case of the scallop, it has been established that the regulatory and essential light chains and the heavy chain are all involved in regulation (Szent-Gy6rgyi et al, 1973;Collins et al, 1986;Vibert and Cohen, 1988), forming a regulatory domain in the neck region of the myosin head (Szentkiralyi, 1984;Winkelmann et al, 1984;Bennett et al, 1984). Fluorescence measurements give evidence for local structural changes in the myosin heads when they bind Ca 2÷ or ATP, and there is evidence that these changes involve movement of the light chains (Hardwicke et al, 1983;Hardwicke and Szent-Gyfrgyi, 1985;.…”

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confidence: 99%

Structural changes induced in Ca2+-regulated myosin filaments by Ca2+ and ATP.

Frado

Craig

1989

The Journal of Cell Biology

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Abstract. We have used electron microscopy and proteolytic susceptibility to study the structural basis of myosin-linked regulation in synthetic filaments of scallop striated muscle myosin. Using papain as a probe of the structure of the head-rod junction, we find that this region of myosin is approximately five times more susceptible to proteolytic attack under activating (ATP/high Ca 2÷) or rigor (no ATP) conditions than under relaxing conditions (ATP/Iow Ca2+). A similar result was obtained with native myosin filaments in a crude homogenate of scallop muscle. Proteolytic susceptibility under conditions in which ADP or adenosine 5'-(~,3~-imidotriphosphate) (AMPPNP) replaced ATP was similar to that in the absence of nucleotide. Synthetic myosin filaments negatively stained under relaxing conditions showed a compact structure, in which the myosin cross-bridges were close to the filament backbone and well ordered, with a clear 14.5-nm axial repeat. Under activating or rigor conditions, the cross-bridges became clumped and disordered and frequently projected further from the filament backbone, as has been found with native filaments; when ADP or AMPPNP replaced ATE the cross-bridges were also disordered. We conclude (a) that Ca 2÷ and ATP affect the affinity of the myosin cross-bridges for the filament backbone or for each other; (b) that the changes observed in the myosin filaments reflect a property of the myosin molecules alone, and are unlikely to be an artifact of negative staining; and (c) that the ordered structure occurs only in the relaxed state, requiring both the presence of hydrolyzed ATP on the myosin heads and the absence of Ca 2÷.

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Domains, motions and regulation in the myosin head

Cited by 93 publications

References 122 publications

Localization of two myosin‐subfragment‐1 binding contacts in the 96–132 region of actin subdomain‐1

Localization of two myosin‐subfragment‐1 binding contacts in the 96–132 region of actin subdomain‐1

Selective cleavage at lysine of the 50 kDa‐20 kDa connector loop segment of skeletal myosin S‐1 by endoproteinase Arg‐C

Structural changes induced in Ca2+-regulated myosin filaments by Ca2+ and ATP.

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