Interaction of skeletal-muscle myosin subfragment-1 with the actin-(338-348) peptide.

Labbé, Jérôme; Lelievre, S; Boyer, Mireille; Benyamin, Yves

doi:10.1042/bj2990875

Cited by 8 publications

(3 citation statements)

References 28 publications

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“…This helix has a number of partially exposed hydrophobic residues including Ile341, Ile345, and Leu346 as well as a buried Trp340. A synthetic hydrophobic peptide of the region 338-348 was shown to bind S1 in the presence and absence of ATP (Labbe et al, 1994), but evidence on the role of specific residues in the 338-348 helix in actomyosin function is still lacking. Initial characterization of the complementary site on myosin is resulting from the myosin cardiomyopathy mutation of Arg405.…”

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confidence: 99%

Mutational Analysis of the Role of Hydrophobic Residues in the 338−348 Helix on Actin in Actomyosin Interactions

et al. 1996

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Yeast actin mutants with alanines replacing I341 and I345 were studied to assess the role of hydrophobic residues in the alpha-helix 338-348 in interactions with myosin. In structural models of the actomyosin complex, this helix on actin was assigned a prominent role in the strong binding of myosin to actin. Substitution of I341 with alanine reduced the strong binding of actin to myosin subfragment-1 (S1) 9-fold compared to wild-type actin. In addition, the Vmax of the actin-activated S1 ATPase was reduced 4-fold with no change in the Km. In contrast, substitution of I345 with alanine had no significant effect on either the strong binding to S1 or the actin activation of S1 ATPase. The I341A actin filaments were found to slide in the in vitro motility assays at a lower mean velocity (1.6 +/- 0.4 microns/s) than wild-type actin filaments (2.6 +/- 0.3 microns/s). Only 65% of the mutant actin filaments moved in such assays in comparison to 95% of the wild-type filaments. However, addition of 2.0 mM MgADP to the motility assay buffer induced movement of all the I341A filaments at a velocity (1.6 +/- 0.1 microns/s) similar to that of wild-type actin (1.7 +/- 0.1 microns/s). The decrease in motility of the I341A actin filaments in the absence of ADP was attributed to a negative load slowing the mutant filaments and the smaller force produced by the heavy meromyosin and I341A actin system. The latter conclusion was confirmed by showing that a greater percentage of NEM-modified heavy meromyosin (external load) was required for arresting the motion of wild-type actin in the in vitro motility assay than that needed for stopping the I341A filaments.

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Mutational Analysis of the Role of Hydrophobic Residues in the 338−348 Helix on Actin in Actomyosin Interactions

et al. 1996

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“…The assumed presence of a ternary complex (actin2-Sll) proposed [8,9] suggests that the environment of Cys374 on one of the two actin molecules is more affected than the other after S1 binding. Since Cys374 occurs close to helix 338 348 [28], there could be an asymmetrical interaction of S1 with each monomer. Such interactions involving two anchorage regions must impose a specific topology through a conformational constraint on F-actin by S l, and the presence of ATP might decrease or hinder the interaction with one of the two monomers during the gliding process.…”

Section: Discussionmentioning

confidence: 99%

“…These two or-helices are outside of subdomain-1 [2] and bear two myosin-binding sites that are effective in the presence of ATP-Mg [5,28] The second motif (a] and a2); al was constituted by sequence residues N92 to P112 comprising hydrophobic residues V96, L110 and clusters L104 and L105. a2 constituted by sequence K359-F375 comprises hydrophobic residues Y362, F375 and the cluster (1369, V370 I ig.…”

Section: Precise Local Analysis Of Hydrophobic Motifs 4 and B Inmentioning

confidence: 99%

Two identical hydrophobic clusters are present on the same actin monomer: interaction between one myosin subfragment‐1 and two actin monomers

Labbé¹,

Boyer²,

Benyamin³

1995

FEBS Letters

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Two-dimensional hydrophobic clusters analysis (IICA) was used to compare the distribution of hydrophobic clusters along various actin sequence. HCA-deduced patterns were not altered by amino-acid variations throughout the evolution of actin and we observed similar hydrophobic motifs comprising myosin subfragment-I ATP-independent binding sites. HCA suggested the presence of two groups of identical hydrophobic motifs (A~ and A2) which bound on each side of the S1 (63 kDa-31 kDa) connecting segment in relation with two actin monomers. This connection is important in communications between actin-and nucleotide-binding sites. We postulate that some relation and message between the two motifs A~ and A 2 take place through myosin subfragment-I (63 kDa-31 kDa) connecting segment.1~ ey words'," Acto-myosin; Hydrophobic cluster; Structure comparison 1~ IntroductionIdentification of the actin-myosin interface is essential in t nderstanding the cyclical enzymatic and mechanical process c f myofibrillar contraction.Atomic resolution of the actin structure [1,2] and the threeciimensional atomic model of F-actin decorated with rabbit ~aymotryptic-S1 [3] or Dictyostelium myosin S1 [4] revealed I ~cations of the myosin head on F-actin. This molecular model f the actin-myosin complex derived from the X-ray structure l zveals a close contact between a myosin subfragment-I and 1 ~o actin monomers. A first contact includes carboxyl residues ,2, 3, 4, 24, 25, 99 and 100. In a second contact, exposed actin 1 ydrophobic residues 144, 341,345,349 and 352 are concerned. "he third contact involves proline residues (332-333) of actin. ~11 of these contacts involve a single monomer. A second mon-~,mer is close to the myosin heavy chain and the interaction i ~cludes the cz-helix formed by actin residues Trp79 to Asn92 flat formed a weak binding contact and was cross-linked [5,6].The Taylor-Amos model [7] of acto-S1 suggests that S1 has n extensive contact with an actin monomer (acl) and a weaker ,. ontact with an adjacent actin monomer (ac2); and two differ-,, nt rigor complexes were suggested [8,9], with SI binding to :-actin occurring in two steps with actin monomers. Using .,uccessively EDC and DMS, we previously cross-linked two lnonomers to 20-kDa and 50-kDa skeletal S1 fragments, re-: Corresponding author. Fax: (33) (67) 60 94 78.spectively [10], and in vitro studies showed that subfragment-I alone can produce the sliding movement of the actin filament [111.Chemical cross-linking [12], NMR [13,14] and immunochemical studies [15,16,[17][18][19][20] have pinpointed actin segments in subdomain-1, residues 1 28, 96-103, 112-125, 338 348 and 360-372 which are able to bind with the myosin head.Furthermore, the (27 kDa-50 kDa-20 kDa) trypsin split myosin subfragment-1, which could no longer be activated by actin, did not bind to the two sites located in the 96-125 region, but it still interacted with the 338-348 and 360--372 segments [191. The presence of hydrophobic interactions in the actin myosin complex have already been sugge...

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Deletion of amino acids from the carboxy‐terminal end of actin

Xia¹,

Peng²

1995

Cell Motil. Cytoskeleton

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A series of deletions was made from the C-terminal end of actin by inserting termination codons into a full length cDNA of human alpha-skeletal muscle actin. These included deletions of 2, 3, 10, 20, 30, and 40 amino acids. The cDNA clones were transcribed and the resulting mRNAs were translated in vitro using 35S-labeled methionine. The 35S-labeled actin and actin mutants were then tested for the ability to coassemble with carrier actin, bind DNAse I, bind myosin S-1, bind a 27 kDa proteolytic fragment of alpha-actinin, and incorporate into myofibrils in vitro. Removal of the C-terminal two or three amino acids did not grossly alter the properties of actin tested. Deletion of an additional 7 amino acids (10 amino acids total) significantly decreased coassembly, binding to DNAse I, and incorporation into myofibrils, but did not dramatically reduce binding to myosin S-1 or the 27 kDa fragment of alpha-actinin. Deletion of 20 or more amino acids virtually abolished all normal actin function tested. By examining the structure of actin, we propose that the effect of removing residues 356-365 is due to the important role Trp356 plays in maintaining hydrophobic bonds between three non-contiguous segments of actin. We also suggest that removal of residues 366-372 adversely affected the structure or orientation of the DNAse I binding loop and that this change can account for defects in actin binding to DNAse I, coassembly with wild type actin, and incorporation into myofibrils.

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Interaction of skeletal-muscle myosin subfragment-1 with the actin-(338-348) peptide.

Cited by 8 publications

References 28 publications

Mutational Analysis of the Role of Hydrophobic Residues in the 338−348 Helix on Actin in Actomyosin Interactions

Mutational Analysis of the Role of Hydrophobic Residues in the 338−348 Helix on Actin in Actomyosin Interactions

Two identical hydrophobic clusters are present on the same actin monomer: interaction between one myosin subfragment‐1 and two actin monomers

Deletion of amino acids from the carboxy‐terminal end of actin

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