The Requirement for Mechanical Coupling Between Head and S2 Domains in Smooth Muscle Myosin ATPase Regulation and its Implications for Dimeric Motor Function

Tama, Florence; Feig, Michael; Li, Jun; Brooks, Charles L.; Taylor, Kenneth A.

doi:10.1016/j.jmb.2004.10.084

Cited by 49 publications

(49 citation statements)

References 92 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This asymmetric intramolecular interaction between the actinbinding region (which includes loop 2) of one head and the converter domain of the second head had been previously reported by others as inducing the "off state" when myosin is dephosphorylated [32][33][34]. Whether the 21-aa insert in NMHC II-B2 locks the myosin heads in this quiescent state and the physiological relevance of expressing this type of myosin in specialized cells such as the cerebellar Purkinje cells of the brain are questions of continuing interest.…”

Section: Discussionsupporting

confidence: 70%

The B2 alternatively spliced isoform of nonmuscle myosin II-B lacks actin-activated MgATPase activity and in vitro motility

Kim

Kawamoto

Bao

et al. 2008

Biochemical and Biophysical Research Communications

View full text Add to dashboard Cite

We report the initial biochemical characterization of an alternatively spliced isoform of nonmuscle heavy meromyosin (HMM) II-B2 and compare it with HMM II-B0, the non-spliced isoform. HMM II-B2 is the HMM derivative of an alternatively spliced isoform of endogenous nonmuscle myosin (NM) II-B, which has 21-amino acids inserted into loop 2, near the actin-binding region. NM II-B2 is expressed in the Purkinje cells of the cerebellum as well as in other neuronal cells (Ma et al., Mol. Biol. Cell 15 (2006) 2138-2149. In contrast to any of the previously described isoforms of NM II (II-A, II-B0, II-B1, II-C0 and II-C1) or to smooth muscle myosin, the actin-activated MgATPase activity of HMM II-B2 is not significantly increased from a low, basal level by phosphorylation of the 20 kDa myosin light chain . Moreover, although HMM II-B2 can bind to actin in the absence of ATP and is released in its presence, it cannot propel actin in the sliding actin filament assay following MLC-20 phosphorylation. Unlike HMM II-B2, the actin-activated MgATPase activity of a chimeric HMM with the 21-amino acids II-B2 sequence inserted into the homologous location in the heavy chain of HMM II-C is increased following MLC-20 phosphorylation. This indicates that the effect of the II-B2 insert is myosin heavy chain specific.

show abstract

Section: Discussionsupporting

confidence: 70%

The B2 alternatively spliced isoform of nonmuscle myosin II-B lacks actin-activated MgATPase activity and in vitro motility

Kim

Kawamoto

Bao

et al. 2008

Biochemical and Biophysical Research Communications

View full text Add to dashboard Cite

show abstract

“…Consistent with the structural and biophysical studies, computational normal mode analysis has suggested that uncoiling of 2-3 heptads at the head-rod junction is necessary for coupling the torsional motions of the S1 heads with the rod to achieve an optimal inhibited state (39). Molecular modeling has also provided a key insight into how ATP binding can cause dephosphorylated smooth muscle myosin filaments to dissociate to the 10 S state in vitro.…”

Section: Role Of the ␣-Helical Coiled-coil Rod In Myosin Regulationmentioning

confidence: 67%

“…Molecular modeling has also provided a key insight into how ATP binding can cause dephosphorylated smooth muscle myosin filaments to dissociate to the 10 S state in vitro. The strain introduced by twisting the separated myosin heads into a compact asymmetric structure may be propagated along the rod so that even the assembly-competent light meromyosin is subject to small distortions that destabilize the rod-rod interactions in the thick filament backbone (39).…”

Section: Role Of the ␣-Helical Coiled-coil Rod In Myosin Regulationmentioning

confidence: 99%

Common Structural Motifs for the Regulation of Divergent Class II Myosins

Lowey

Trybus

2010

Journal of Biological Chemistry

View full text Add to dashboard Cite

This minireview focuses on structural studies that have provided insights into our current understanding of thick filament regulation in muscle. We describe how different domains in the myosin molecule interact to produce an inactive "off" state; included are head-head and head-rod interactions, the role of the regulatory light chain, and the significance of the ␣-helical coiled-coil rod in regulation. Several of these interactions have now been visualized in a wide variety of native myosin filaments, testifying to the generality of these structural motifs across the phylogenetic tree.The publication of the crystal structure of the globular head region of skeletal muscle myosin (subfragment 1 (S1)3 ) in 1993 (1) made it possible for the first time to understand how biological motors function at the atomic level (Fig. 1, A and B). By fitting, the S1 head structure into macromolecular complexes of actin filaments decorated with S1, Rayment et al. (2) were able to propose the first detailed mechanism for the generation of force and movement in motile cells. This exciting new structural framework, together with impressive advances in determining the displacement and force produced by a single molecular motor, inspired a Biophysical Discussions meeting in 1994. We discussed the role of the light chains in the so-called "lever arm" of the myosin head (3). Here, we summarize some of the major developments in the regulation of class II myosins in the intervening 15 years.

show abstract

“…26,27,34,35 Thus, based on the assumption that conformational transformations of the dimerization interface of a GPCR can be discriminated based on the number of low frequency modes that describe them, 35 we calculated the contribution of the 100 lowest frequency normal modes of the 1N3M-like rhodopsin tetramer 5 to each of the postulated activated interface models obtained as described in the Methods section.…”

Section: Contribution Of Low Frequency Normal Modes To Molecular Modementioning

confidence: 99%

Influence of oligomerization on the dynamics of G‐protein coupled receptors as assessed by normal mode analysis

Niv

Filizola

2007

Proteins

View full text Add to dashboard Cite

The recently discovered impact of oligomerization on G-protein coupled receptor (GPCR) function further complicates the already challenging goal of unraveling the molecular and dynamic mechanisms of these receptors. To help understand the effect of oligomerization on the dynamics of GPCRs, we have compared the motion of monomeric, dimeric, and tetrameric arrangements of the prototypic GPCR rhodopsin, using an approximate-yet powerful-normal mode analysis (NMA) technique termed elastic network model (ENM). Moreover, we have used ENM to discriminate between putative dynamic mechanisms likely to account for the recently observed conformational rearrangement of the TM4,5-TM4,5 dimerization interface of GPCRs that occurs upon activation. Our results indicate: (1) significant perturbation of the normal modes (NMs) of the rhodopsin monomer upon oligomerization, which is mainly manifested at interfacial regions; (2) increased positive correlation among the transmem-brane domains (TMs) and between the extracellular loop (EL) and TM regions of the rhodopsin protomer; (3) highest inter-residue positive correlation at the interfaces between protomers; and (4) experimentally testable hypotheses of differential motional changes within different putative oligomeric arrangements.

show abstract

The Requirement for Mechanical Coupling Between Head and S2 Domains in Smooth Muscle Myosin ATPase Regulation and its Implications for Dimeric Motor Function

Cited by 49 publications

References 92 publications

The B2 alternatively spliced isoform of nonmuscle myosin II-B lacks actin-activated MgATPase activity and in vitro motility

The B2 alternatively spliced isoform of nonmuscle myosin II-B lacks actin-activated MgATPase activity and in vitro motility

Common Structural Motifs for the Regulation of Divergent Class II Myosins

Influence of oligomerization on the dynamics of G‐protein coupled receptors as assessed by normal mode analysis

Contact Info

Product

Resources

About