ライフサイエンスコーパス: myosin head

1 ilizing the closed switch 2 structure of the myosin head.

2 , indicating considerable flexibility in the myosin head.

3 interact with the ATP hydrolysis site in the myosin head.

4 bound and exerted chaperone activity on the myosin head.

5 ied by a disorder-to-order transition of the myosin head.

6 n and reveals an unusual conformation of the myosin head.

7 rIA-labeled RLC is functionally bound to the myosin head.

8 rminal UCS domain known to interact with the myosin head.

9 al orientation and rotational motions of the myosin head.

10 ally due to drag forces from weakly attached myosin heads.

11 ar to be due to the longitudinal addition of myosin heads.

12 e to an axial perturbation of some levels of myosin heads.

13 f the resistive population of strongly bound myosin heads.

14 on of lever arm angles of the actin-attached myosin heads.

15 the 14.5 nm axial spacing between crowns of myosin heads.

16 n is partially available for weak binding of myosin heads.

17 of myosin head domains or the orientation of myosin heads.

18 hich reciprocally affects the motions of the myosin heads.

19 o transitions in the dynamics of interacting myosin heads.

20 insert can affect the cooperativity between myosin heads.

21 tween the functional behavior of MRP and MHC myosin heads.

22 c packing but is enforced by elements of the myosin heads.

23 acterized the motions of these force-bearing myosin heads.

24 ed, directly demonstrating signaling between myosin heads.

25 n intact, a distortion must occur within the myosin heads.

26 ls an asymmetric interaction between the two myosin heads.

27 tile filament array alter the motions of the myosin heads.

28 ted with a conformational equilibrium of the myosin heads.

29 where Tpm shields actin from the binding of myosin heads.

30 ulated thin filaments even in the absence of myosin heads.

31 s and cooperative interactions between bound myosin heads.

32 duce an M-region (bare zone) that is free of myosin heads.

33 These torsional motions of the myosin heads about their coiled coil alpha-helices affec

34 the function of S2 in accommodating variable myosin head access to actin.

35 ed changes in X-ray reflections arising from myosin heads, actin filaments, troponin, and tropomyosin

36 In the absence of nucleotide and at low myosin head/actin ratios, only phosphorylated heads indu

37 even more dramatic, in that at all levels of myosin head/actin, phosphorylation was necessary to affe

38 ta suggest that the regulatory domain of the myosin head acts as a single mechanically rigid body, co

39 M3 reflection from the regular repeat of the myosin heads along the filaments decreased in proportion

40 confirmed the axial tilt; but strongly bound myosin heads also showed an unexpected azimuthal slew of

41 which induced oxidative modifications in the myosin head and in actin, as previously reported.

42 The peak angle between the lever axis of the myosin head and the fiber or actin filament axis was 100

43 conserved interactions between the 'blocked' myosin head and the myosin tail, which may contribute to

44 erable flexibility in the orientation of the myosin head and the position of the S1-S2 junction is ne

45 of myofibrillogenesis are independent of the myosin head and these processes are regulated by the myo

46 tin-based alteration of the distance between myosin heads and actin.

47 defined interactions sites between adjacent myosin heads and associated protein partners, and then a

48 f two rich layer-line patterns, one from the myosin heads and based on a 429 A axial repeat, and one

49 meridional reflections come from unattached myosin heads and from backbone components of the myosin

50 sociated with the quasi-helical order of the myosin heads and myosin binding protein C (MyBP-C) decre

51 iled alpha-helix at the junction between the myosin heads and S2, and the dependence of regulation on

52 eloped a cross-bridge model with independent myosin heads and strain-dependent interstate transition

53 ure directly affects the conformation of the myosin heads and that they need to be in a particular co

54 explore how coupled motions between the two myosin heads and the dimerization domain (S2) in smooth

55 ype filament reveals the conformation of the myosin heads and the organization of titin and MyBP-C at

56 the different interference functions for the myosin heads and the thick filament backbone.

57 e absence of Ca, the interaction between the myosin heads and the thin filaments was most likely the

58 he structures of thick filaments had ordered myosin heads and were distinguishable from each other by

59 a hinge in the coiled coil, allowing the two myosin 'heads' and their motor domains to interact with

60 elastic distortion of the RLC region of the myosin head, and during the subsequent rapid force recov

61 to the actin-binding domain of the perinatal myosin head, and is close to the ATP-binding site.

62 Myosin heads appear to interact with each other intramol

63 Mutations in the myosin head are thought to affect the ATPase and actin-b

64 in) of around 16%, but most of the remaining myosin heads are also actin-attached even at moderate ac

65 In the M.ADP state, myosin heads are also disordered.

66 ric contraction either less than 17 % of the myosin heads are attached to actin, or that heads can de

67 aximal shortening velocity, only 10 % of the myosin heads are attached to the thin filaments at any o

68 hydrolysis, although a small fraction of the myosin heads are constitutively ON.

69 In relaxed muscle, the myosin heads are helically ordered and undergo minimal i

70 Myosin heads are helically ordered on the thick filament

71 in label probes showed that dephosphorylated myosin heads are highly ordered in the relaxed fibers an

72 perties of the protein chains connecting the myosin heads are important.

73 the RLCs of the interacting free and blocked myosin heads are in different environments.

74 However, if the myosin heads are long enough to span the actin helical r

75 Analysis of these data suggests that two myosin heads are required to activate the thin filament.

76 n S1/actin ratio of 0.4, suggesting that 2-3 myosin heads are required to immobilize cardiac Tm.

77 We have found that two myosin heads are required to laterally activate a regula

78 t understood, although it is known that both myosin heads are required.

79 n rigor (in the absence of ATP, when all the myosin heads are rigidly bound to the thin filament), a

80 that during isometric contraction 29% of the myosin heads are strongly bound to actin within the myof

81 viously suggested that the helical tracks of myosin heads are zigzagged, short diagonal ridges being

82 the analysis of interference effects between myosin head arrays in the two halves of the thick filame

83 *ATP state, the orientations of the attached myosin heads assume a wide range of azimuthal and axial

84 nergy transfer experiment confirmed that the myosin head assumes a more compact conformation in the p

85 age isometric force exerted by each attached myosin head at 5 degrees C, 4.5 pN, and the maximum slid

86 rearrangements of actin, tropomyosin and the myosin heads at different stages of actomyosin cycle in

87 rast, actin-bound caldesmon was not moved by myosin heads at low head/actin ratios, as uncovered by f

88 usters and anisotropy of force generation by myosin heads at the ends of the myosin clusters.

89 after rapid freezing, show binding of single myosin heads at varying angles that is largely restricte

90 We have defined the myosin head atomic arrangements within the three crown l

91 The fraction of myosin heads attached to actin during unloaded shortenin

92 ocal bending of the filament front upon each myosin head attachment.

93 This increases the number of myosin heads available to rapidly bind to actin and cont

94 and electron microscopy revealed that mutant myosin heads bear a dramatic propensity to collapse and

95 Complete regulation requires two intact myosin heads because single-headed myosin subfragments a

96 ated myosin filaments, the helically ordered myosin heads become disordered and project further from

97 indicating that relay helix, like the entire myosin head, bends in the recovery stroke.

98 ance energy transfer (FRET) as a function of myosin head binding to actin.

99 ropomyosin position and would interfere with myosin head binding to actin.

100 own by three independent approaches to track myosin head binding to the thin filament, but is absent

101 s been shown that skeletal and smooth muscle myosin heads binding to actin results in the movement of

102 ed the largest variation indicating that the myosin head binds MgATP more tightly in the order IIA (8

103 Intramolecular interaction between myosin heads, blocking key sites involved in actin-bindi

104 sis, even with a significant fraction of the myosin heads bound to actin.

105 Conventional EPR shows that myosin heads bound to oriented actin filaments are highl

106 ges, active cross-bridges are usually single myosin heads, bound preferentially to actin target zones

107 hat the azimuth of S2 origins of those rigor myosin heads, bound to the actin target zone of actively

108 rder requires the closed conformation of the myosin head but is not dependent on the hydrolysis of AT

109 We have measured the step size of individual myosin heads by fusing an enhanced green fluorescent pro

110 measured the number and position of attached myosin heads by tracing cross-bridges through the three-

111 upling between myosin, that assumes a single myosin head can activate the thin filament.

112 e S1-S2 junction is necessary, such that the myosin head can bind to a nearby actin whereas the tail

113 ational results of a half sarcomere with 150 myosin heads can explain the experimentally measured for

114 alytic and lever arm domains of noncompetent myosin heads change angle on actin, whereas lever arm mo

115 ellular process, possibly by positioning the myosin head closer to actin.

116 sm of muscle activation in the thin filament-myosin head complex under physiological conditions.

117 Myosin head consists of a globular catalytic domain and

118 termined the structure of the intact scallop myosin head, containing both the motor domain and the le

119 is possible that this pliant junction in the myosin head contributes to the compliance known to be pr

120 harp meridional reflections, signifying that myosin heads (cross-bridges) are distributed in a well-o

121 M-band (M6', M4', M1, M4 and M6) and in the myosin head crowns (P1, P2 and P3) at the M-region edges

122 The mechanism of force generation by the myosin head depends on the relationship between cross-br

123 and residues on a single flat surface on the myosin head described as the myosin mesa.

124 e with the contributions from actin-attached myosin heads determines the behavior of these reflection

125 The 3.1-A x-ray structure of the scallop myosin head domain (subfragment 1) in the ADP-bound near

126 with myosin to promote proper folding of the myosin head domain are not known.

127 fully accounted for by the compliance of the myosin head domain, 0.38 +/- 0.06 nm pN(-1), obtained fr

128 Myosin-VIIb has a conserved myosin head domain, five IQ domains, two MyTH4 domains c

129 the OFF state of the thick filament in which myosin head domains are more parallel to the filament ax

130 functional rhodamine probes on the cRLC: the myosin head domains became more perpendicular to the fil

131 Docking of atomic models of scallop myosin head domains into the motifs reveals that the hea

132 is not affected by either the proportion of myosin head domains or the orientation of myosin heads.

133 ive information about axial movements of the myosin heads during contraction with sub-nanometer resol

134 2-fold change of the global dynamics of the myosin head, effected by decreasing the interactions wit

135 teristic 42.9 nm quasi-helical repeat of the myosin heads expected from x-ray diffraction.

136 d structure had narrow shafts and disordered myosin heads extending at different angles from the back

137 availability of the majority fraction of the myosin heads for contraction is controlled in part by th

138 This implies that myosin heads form a shell around the filament axis, cons

139 hese filaments to ATP hydrolysis by attached myosin head fragments (S1).

140 e to those of the corresponding RLC lobes in myosin head fragments bound to isolated actin filaments

141 iological; it may function to make activated myosin heads freer to contact actin filaments during mus

142 hree-dimensional structures of the truncated myosin head from Dictyostelium discoideum myosin II comp

143 the sliding velocity of actin filaments past myosin heads from 9.0 +/- 1.3 to 5.7 +/- 1.0 mum/s at 0.

144 ection (M6) and the equilibrium positions of myosin heads from the fourth myosin layer line peak posi

145 skeletal muscle can be increased by shifting myosin heads from the super-relaxed state (SRX), with a

146 The low C(cb) value indicates that the myosin head generates isometric force by a small sub-ste

147 suggesting that at a higher temperature the myosin head generates more force.

148 Previous crystal structures of the myosin head have shown two different conformations, post

149 Fewer than 4% of the myosin heads have ADP bound in rigor, and the time cours

150 ilament lattice spacing, the majority of the myosin heads have their light chain domains in IHM-like

151 ing is a feasible approach for investigating myosin head-head interactions in solution.

152 nd may relieve the tether-like constraint of myosin heads imposed by cMyBP-C.

153 e we compare the overall organization of the myosin head in these three states and show how the confo

154 We investigated the importance of the myosin head in thick filament formation and myofibrillog

155 Instead, it blocks the myosin heads in a products complex with low actin affini

156 However, OM also traps a population of myosin heads in a weak actin affinity state with slow pr

157 in active, isometric muscle, the fraction of myosin heads in any given biochemical state is independe

158 tation of the dephosphorylated RLC region of myosin heads in cardiac muscle is primarily determined b

159 n the two lobes of the RLC to actin-attached myosin heads in muscle fibers, and suggest that such ben

160 chemical coupling is localized to individual myosin heads in muscle.

161 ffect of temperature on the helical order of myosin heads in rabbit psoas muscle in the presence of n

162 onformation of the light chain domain of the myosin heads in relaxed demembranated fibers from rabbit

163 en adjacent actin binding sites and adjacent myosin heads in response to cross-bridge attachment/deta

164 contrast to the nearly crystalline order of myosin heads in rigor.

165 only about 17 % of the concentration of the myosin heads in the fibre, suggesting that during isomet

166 te similar behavior of SH1- and SH2-modified myosin heads in the in vitro motility assays despite som

167 However, it was shown that the myosin heads in the M*ATP state exhibited a disordered d

168 t with a H(2)O(2)-induced loss of functional myosin heads in the muscle.

169 Thus, myosin heads in the regions of the thick filaments that

170 25 degrees C, where approximately 95% of the myosin heads in the skinned rabbit psoas muscle contain

171 viding further support for the proposal that myosin heads in the SRX are also in the interacting-head

172 The alignment of the myosin heads in the thick filaments and the alignment of

173 It has been proposed that myosin heads in this state are inhibited by binding to t

174 ADP, induce the "closed" conformation of the myosin head (in which the gamma phosphate pocket is clos

175 It is based on three premises: (i) the myosin head incorporates a lever arm, whose equilibrium

176 n upon addition of skeletal or smooth muscle myosin heads, indicating a movement of the whole tropomy

177 cules suggests that an increased mobility of myosin heads induced by Ca2+ binding underlies the chang

178 By assuming that the binding of myosin heads induces and/or stabilizes local conformatio

179 close to the actin-binding interface of the myosin head influence actin binding and thereby modulate

180 by an asymmetric interaction between the two myosin heads, inhibiting their actin binding or ATPase a

181 We conclude that in the "off" state, scallop myosin heads interact with each other, forming a rigid s

182 In the knockout filament, some of the myosin head interactions are disrupted, suggesting that

183 ecent models suggesting a pre-cocking of the myosin head involving an enormous rotation between the l

184 eorientation of the regulatory domain of the myosin head is a feature of all current models of force

185 The regulatory domain of the myosin head is believed to serve as a lever arm that amp

186 of rabbit shows that stiffness of the rabbit myosin head is only approximately 62% of that in frog.

187 telium myosin motor domain revealed that the myosin head is required to bend at residues Ile-455 and

188 productive blebbistatin-binding site of the myosin head is within the aqueous cavity between the nuc

189 hat upon stretch the fraction of actin-bound myosin heads is higher than during isometric contraction

190 we predict that the average number of bound myosin heads is regulated by the external force and nucl

191 ta show that a small fraction of actin-bound myosin heads is sufficient for supporting the O-state an

192 The orientation of the strongly bound myosin heads is uniform ("stereospecific" attachment), a

193 direct information about the position of the myosin head lever arm; they are, in fact, reporting rela

194 the attached A*M*ATP cross-bridges while the myosin heads maintain some degree of helical distributio

195 Myosin heads may accumulate in a preforce state that pro

196 nique attachment configuration: the "primed" myosin heads may function as "transient struts" when att

197 Small-angle x-ray diffraction indicates that myosin heads move increasingly toward the thin filament

198 m series compliance; force drops faster when myosin heads move relative to actin during relaxation.

199 at the force-generating mechanism within the myosin heads must have some unexpected properties.

200 During normal muscle shortening, the myosin heads must undergo many cycles of interaction wit

201 d to F-actin and simultaneously activate the myosin heads of adjacent myosin filaments at a distance

202 ange in orientation of the RLC region of the myosin heads on activation of cardiac muscle is small; t

203 ving changes in both the organisation of the myosin heads on its surface and the axial periodicity of

204 s of blebbistatin on the organization of the myosin heads on muscle thick filaments.

205 d/superrelaxed quasi-helical ordering of the myosin heads on the filament surface, whereas phosphoryl

206 n head.We have modelled the surface array of myosin heads on the filaments using as a building block

207 Myosin heads on the surface of the thick filament in rel

208 correlation between the conformation of the myosin heads on the surface of the thick filaments and t

209 ing of Ca(2+) to, or phosphorylation of, the myosin heads on the surface of the thick filaments.

210 of muscle involves the cyclic interaction of myosin heads on the thick filaments with actin subunits

211 , where contraction is regulated through the myosin heads on the thick filaments.

212 ing speed and the isometric force exerted by myosin heads on the thin filaments.

213 racterized by helical packing of most of the myosin head or motor domains on the thick filament surfa

214 sibly indicating flexibility of the attached myosin heads or probing of their vicinity.

215 y of cross-bridge formation remains high for myosin heads originating within 8 nm axially of the targ

216 callop) filaments reveals a helical array of myosin head-pair motifs above the filament surface.

217 uction shows axial and azimuthal (no radial) myosin head perturbations within the 429-A axial repeat,

218 osin position on actin by phosphorylation of myosin heads plays a key role in the regulation of smoot

219 the actomyosin ATPase and (b) as to why the myosin head positions in phosphorylated wild-type mice a

220 e fish muscle A-band lattice relative to the myosin head positions, and that these newly observed X-r

221 into a strong, stereo-specific complex, the myosin heads push Tpm strand to the open, or O, state al

222 ine the dynamics of the proximal part of the myosin head (regulatory domain) which accompany the chan

223 rovides a measure of the distance over which myosin heads remain attached to actin as they go through

224 hich it contributes to proper folding of the myosin head remains unclear.

225 deled using FRET distance changes within the myosin head reported here and previously.

226 Probes on unphosphorylated myosin heads reported similar structural changes when ne

227 correlation and the biochemical state of the myosin heads required to obtain the helical array has no

228 ested whether the helical arrangement of the myosin heads requires the M.ADP.P(i) state.

229 , presumably due to a compliant point in the myosin head(s).

230 the catalytic and regulatory domains of the myosin head (S1) is likely to be the force generating co

231 with a phosphorescent probe at C374, and the myosin head (S1) was separated into isoenzymes S1A1 and

232 in filaments can also be activated by strong myosin head (S1)-actin interactions.

233 of weakly (+ATP) and strongly (no ATP) bound myosin heads (S1) on the microsecond dynamics of actin l

234 The binding of myosin heads (S1) to actin-Tm at low levels of saturatio

235 The binding of myosin heads (S1) to the Tm-F-actin complexes increased

236 nce fringes (which measures the shift of the myosin heads scattering mass towards the center of the s

237 d-flow studies suggested that strongly bound myosin head significantly increased the Ca2+ sensitivity

238 This appears to ensure proper folding of myosin heads so that they can perform their ATP-dependen

239 ion results showed a 1.0 to 1.5% increase in myosin head spacing with activation; however, this incre

240 states of the contractile cycle in which the myosin heads stay detached from actin.

241 similar to those in frog, while the average myosin head stiffness of dogfish (1.98 +/- 0.31 pN nm(-1

242 CaP binding to myosin head strengthened upon phosphorylation of RLC by

243 s actin movement against the viscous drag of myosin heads strongly bound to actin (Hill's dashpot).

244 oximately 2-fold decrease in the fraction of myosin heads strongly bound to actin.

245 The locations of variants on isolated myosin head structures predict contractility effects but

246 We showed previously that myosin head (subfragment 1, S1) directly interacts with

247 ransduction of conformational changes in the myosin head (subfragment-1 (S1)).

248 the domains bind to distinct subsites on the myosin head, suggesting distinct roles in forming the my

249 resents the pre-hydrolysis structure for the myosin head that occurs after release from actin.

250 erturb the orientations of the population of myosin heads that are attached to actin, and thereby cha

251 pling of regulated binding sites and cycling myosin heads that are induced by interfilamentary moveme

252 tential for interaction between troponin and myosin heads that bind near it along the thin filament r

253 of wild type, supporting the hypothesis that myosin heads that lack phosphorylated RLC remain close t

254 conclude that the loosening of the array of myosin heads that occurs on activation is real and physi

255 chanical characteristics of myofilaments and myosin heads that underpin refined models of the acto-my

256 ions with the filament surface (or the other myosin head), the coupling of the intradomain dynamics r

257 Analysis of the interactions between the myosin heads, the cardiac isoform of myosin-binding prot

258 ucture, and function (ATPase motor) to other myosin heads, the organization of the tail has been less

259 the filament and the degree of order of the myosin heads, thick filaments isolated from a control gr

260 By regulating the actin attachment of myosin heads, this provides a basis for energy-efficient

261 presence of both Ca2+ and strong binding of myosin head to actin was required to achieve a fully ope

262 n that occurs during the weak binding of the myosin head to actin.

263 There is enough freedom for the myosin head to find the next location of the binding sit

264 n and the slow rate of ADP release helps the myosin head to remain attached to actin for a large frac

265 The binding of myosin heads to actin increases the calcium sensitivity

266 nding model for the binding of caldesmon and myosin heads to actin.

267 and indicate that helical order requires the myosin heads to be in the closed conformation.

268 n filament and thereby limits the ability of myosin heads to move tropomyosin.

269 roke generates muscle contraction by causing myosin heads to pull on actin filaments.

270 of muscle contraction the initial binding of myosin heads to the actin thin filament contributes to s

271 red here correlates well with the binding of myosin heads to the core of the thick filament in a stru

272 gment 2 (S2), the segment that links the two myosin heads to the thick filament backbone, may serve a

273 ructural studies to stabilize the binding of myosin heads to the thick filament, and here we have uti

274 Binding of rigor myosin heads to thin filaments following MgATP depletion

275 a complementary role in moving and orienting myosin heads toward actin target sites, thereby increasi

276 Furthermore, the expected increase in myosin head transfer by dobutamine was significantly blu

277 This domain of the myosin head transmits conformational changes in the nucl

278 In contrast, myosin, isolated myosin heads, tropomyosin, and troponin exhibited no spe

279 actin and myosin and between residues of the myosin head underlies the mechanism of force generation.

280 small ensemble of myosin ( approximately 12 myosin heads) using a three-bead laser trap assay.

281 hanical characteristics of the filaments and myosin heads vary in muscles of different animals we app

282 maximum axial movement of the distal part of myosin head was modeled using FRET distance changes with

283 The shift of myosin heads was detected by a change in fluorescent int

284 ra density, reflecting weakly bound, cycling myosin heads, was also detected, on the extreme peripher

285 eature approximately the size and shape of a myosin head.We have modelled the surface array of myosin

286 he inner domain of actin, and strongly bound myosin heads were now observed over the junction of the

287 he mutation decreased also the amount of the myosin heads which bound strongly to actin at high Ca(2+

288 moves tropomyosin in one direction, whereas myosin heads, which enhance potentiation, move tropomyos

289 the mechanical transitions made by a single myosin head while it is attached to actin.

290 ngements of the four major subdomains in the myosin head with different bound nucleotides.

291 oth the UCS and the Central domains bind the myosin head with high affinity, only the UCS domain disp

292 However, interaction of the myosin head with other myofibrillar components is necess

293 The position of the myosin head with respect to the filament backbone is tho

294 t structure that decrease the interaction of myosin heads with actin thin filaments.

295 These results imply that the interaction of myosin heads with actin within an intact sarcomere chang

296 are close to those expected for actin-bound myosin heads with their light chain domains in a pre-pow

297 ase of the ATP-powered cyclic interaction of myosin heads with thin filaments.

298 ults and examine the fraction of actin-bound myosin heads within the myofilament lattice during calci

299 tric force is a larger fraction of the total myosin head working stroke in the dogfish than in the fr

300 As a result, the myosin heads would always be attached to a tether that h