scholarly journals Redox-sensitive residue in the actin-binding interface of myosin

2014 ◽  
Vol 453 (3) ◽  
pp. 345-349 ◽  
Author(s):  
Rebecca J. Moen ◽  
Sinziana Cornea ◽  
Daniel E. Oseid ◽  
Benjamin P. Binder ◽  
Jennifer C. Klein ◽  
...  
Keyword(s):  
Actin Binding ◽  
Binding Interface

scholarly journals Visualization of Head–Head Interactions in the Inhibited State of Smooth Muscle Myosin

1999 ◽  
Vol 147 (7) ◽  
pp. 1385-1390 ◽  
Author(s):  
Thomas Wendt ◽  
Dianne Taylor ◽  
Terri Messier ◽  
Kathleen M. Trybus ◽  
Kenneth A. Taylor
Keyword(s):  
Smooth Muscle ◽  
Smooth Muscle Myosin ◽  
Intramolecular Interactions ◽  
Actin Binding ◽  
Structural Basis ◽  
Binding Interface ◽  
Structural Differences ◽  
Muscle Myosin ◽  
Positively Charged ◽  
Phosphoryla Tion

The structural basis for the phosphoryla- tion-dependent regulation of smooth muscle myosin ATPase activity was investigated by forming two- dimensional (2-D) crystalline arrays of expressed unphosphorylated and thiophosphorylated smooth muscle heavy meromyosin (HMM) on positively charged lipid monolayers. A comparison of averaged 2-D projections of both forms at 2.3-nm resolution reveals distinct structural differences. In the active, thiophosphorylated form, the two heads of HMM interact intermolecularly with adjacent molecules. In the unphosphorylated or inhibited state, intramolecular interactions position the actin-binding interface of one head onto the converter domain of the second head, thus providing a mechanism whereby the activity of both heads could be inhibited.

The Actin-Binding Interface of a Myosin III Is PhosphorylatedinVivoin Response to Signals from a Circadian Clock†

Biochemistry ◽  
2007 ◽  
Vol 46 (48) ◽  
pp. 13907-13919 ◽  
Author(s):  
Helene L. Cardasis ◽  
Stanley M. Stevens ◽  
Scott McClung ◽  
Karen E. Kempler ◽  
David H. Powell ◽  
...  
Keyword(s):  
Circadian Clock ◽  
Actin Binding ◽  
Binding Interface

scholarly journals The crystal structure of the C-terminus of adseverin reveals the actin-binding interface

2009 ◽  
Vol 106 (33) ◽  
pp. 13719-13724 ◽  
Author(s):  
S. Chumnarnsilpa ◽  
W. L. Lee ◽  
S. Nag ◽  
B. Kannan ◽  
M. Larsson ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Actin Binding ◽  
Binding Interface ◽  
C Terminus

scholarly journals Actin-Resistant DNase1L2 as a Potential Therapeutics for CF Lung Disease

Biomolecules ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 410
Author(s):  
Danila Delfino ◽  
Giulia Mori ◽  
Claudio Rivetti ◽  
Antonella Grigoletto ◽  
Gloria Bizzotto ◽  
...  
Keyword(s):  
Lung Disease ◽  
Plasmid Dna ◽  
Actin Binding ◽  
Recurrent Infections ◽  
Binding Interface ◽  
Airway Clearance ◽  
Dependent Endonuclease ◽  
Model Structures ◽  
Potential Therapeutics ◽  
Pegylated Form

In cystic fibrosis (CF), the accumulation of viscous lung secretions rich in DNA and actin is a major cause of chronic inflammation and recurrent infections leading to airway obstruction. Mucolytic therapy based on recombinant human DNase1 reduces CF mucus viscosity and promotes airway clearance. However, the marked susceptibility to actin inhibition of this enzyme prompts the research of alternative treatments that could overcome this limitation. Within the human DNase repertoire, DNase1L2 is ideally suited for this purpose because it exhibits metal-dependent endonuclease activity on plasmid DNA in a broad range of pH with acidic optimum and is minimally inhibited by actin. When tested on CF artificial mucus enriched with actin, submicromolar concentrations of DNase1L2 reduces mucus viscosity by 50% in a few seconds. Inspection of superimposed model structures of DNase1 and DNase1L2 highlights differences at the actin-binding interface that justify the increased resistance of DNase1L2 toward actin inhibition. Furthermore, a PEGylated form of the enzyme with preserved enzymatic activity was obtained, showing interesting results in terms of activity. This work represents an effort toward the exploitation of natural DNase variants as promising alternatives to DNase1 for the treatment of CF lung disease.

scholarly journals Binding to F-actin guides cadherin cluster assembly, stability, and movement

2013 ◽  
Vol 201 (1) ◽  
pp. 131-143 ◽  
Author(s):  
Soonjin Hong ◽  
Regina B. Troyanovsky ◽  
Sergey M. Troyanovsky
Keyword(s):  
Adherens Junction ◽  
Random Motion ◽  
Binding Domain ◽  
Actin Binding ◽  
Cluster Assembly ◽  
Structural Elements ◽  
Binding Interface ◽  
Extracellular Region ◽  
Actin Binding Domain ◽  
Intracellular Binding

The cadherin extracellular region produces intercellular adhesion clusters through trans- and cis-intercadherin bonds, and the intracellular region connects these clusters to the cytoskeleton. To elucidate the interdependence of these binding events, cadherin adhesion was reconstructed from the minimal number of structural elements. F-actin–uncoupled adhesive clusters displayed high instability and random motion. Their assembly required a cadherin cis-binding interface. Coupling these clusters with F-actin through an α-catenin actin-binding domain (αABD) dramatically extended cluster lifetime and conferred direction to cluster motility. In addition, αABD partially lifted the requirement for the cis-interface for cluster assembly. Even more dramatic enhancement of cadherin clustering was observed if αABD was joined with cadherin through a flexible linker or if it was replaced with an actin-binding domain of utrophin. These data present direct evidence that binding to F-actin stabilizes cadherin clusters and cooperates with the cis-interface in cadherin clustering. Such cooperation apparently synchronizes extracellular and intracellular binding events in the process of adherens junction assembly.

scholarly journals Conformational dynamics regulate SHANK3 actin and Rap1 binding

2020 ◽  
Author(s):  
Siiri I Salomaa ◽  
Mitro Miihkinen ◽  
Elena Kremneva ◽  
Ilkka Paatero ◽  
Johanna Lilja ◽  
...  
Keyword(s):  
Dendritic Spine ◽  
Conformational Dynamics ◽  
Small Gtpases ◽  
Actin Binding ◽  
Risk Gene ◽  
Binding Interface ◽  
Dendritic Spine Morphology ◽  
Functional Implications ◽  
The Stability

AbstractActin-rich cellular protrusions direct versatile biological processes from cancer cell invasion to dendritic spine development. The stability, morphology and specific biological function of these protrusions are regulated by crosstalk between three main signaling axes: integrins, actin regulators and small GTPases. SHANK3 is a multifunctional scaffold protein, interacting with several actin-binding proteins, and a well-established autism risk gene. Recently, SHANK3 was demonstrated to sequester integrin-activating small GTPases Rap1 and R-Ras to inhibit integrin activity via its N-terminal SPN domain. Here, we demonstrate that SHANK3 interacts directly with actin using its SPN domain. Actin binding can be inhibited by an intramolecular closed conformation of SHANK3, where the adjacent ARR domain covers the actin-binding interface of the SPN domain. Actin and Rap1 compete with each other for binding to SHANK3 and loss of SHANK3-actin binding augments inhibition of Rap1-mediated integrin activity. This dynamic crosstalk has functional implications for filopodia formation in cancer cells, dendritic spine morphology in neurons and autism-linked phenotypes in vivo.

scholarly journals Calponin Repeats Regulate Actin Filament Stability and Formation of Podosomes in Smooth Muscle Cells

2003 ◽  
Vol 14 (6) ◽  
pp. 2482-2491 ◽  
Author(s):  
Mario Gimona ◽  
Irina Kaverina ◽  
Guenter P. Resch ◽  
Emmanuel Vignal ◽  
Gerald Burgstaller
Keyword(s):  
Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Actin Cytoskeleton ◽  
Actin Filament ◽  
Ectopic Expression ◽  
Muscle Cells ◽  
Actin Binding ◽  
Binding Interface ◽  
The Stability ◽  
Cytoskeleton Rearrangements

Phorbol ester induces actin cytoskeleton rearrangements in cultured vascular smooth muscle cells. Calponin and SM22 α are major components of differentiated smooth muscle and potential regulators of actin cytoskeleton interactions. Here we show that actin fibers decorated with h1 CaP remain stable, whereas SM22 α-decorated actin bundles undergo rapid reorganization into podosomes within 30 min of PDBu exposure. Ectopic expression of GFP α-actinin had no effect on the stability of the actin cytoskeleton and α-actinin was transported rapidly into PDBu-induced podosomes. Our results demonstrate the involvement of CaP and SM22 α in coordinating the balance between stabilization and dynamics of the actin cytoskeleton in mammalian smooth muscle. We provide evidence for the existence of two functionally distinct actin filament populations and introduce a molecular mechanism for the stabilization of the actin cytoskeleton by the unique actin-binding interface formed by calponin family-specific CLIK23 repeats.

Distribution of c-protein isoforms in sarcomeres of developing chick skeletal muscle

1988 ◽  
Vol 46 ◽  
pp. 226-227
Author(s):  
D. A. Fischman ◽  
J. E. Dennis ◽  
T. Obinata ◽  
H. Takano-Ohmuro
Keyword(s):  
Skeletal Muscles ◽  
Thick Filament ◽  
Protein Isoforms ◽  
Actin Binding ◽  
Striated Muscles ◽  
C Protein ◽  
Sarcomeric Protein ◽  
Thick Filaments ◽  
Cross Bridges ◽  
Bridge Bearing

C-protein is a 150 kDa protein found within the A bands of all vertebrate cross-striated muscles. By immunoelectron microscopy, it has been demonstrated that C-protein is distributed along a series of 7-9 transverse stripes in the medial, cross-bridge bearing zone of each A band. This zone is now termed the C-zone of the sarcomere. Interest in this protein has been sparked by its striking distribution in the sarcomere: the transverse repeat between C-protein stripes is 43 nm, almost exactly 3 times the 14.3 nm axial repeat of myosin cross-bridges along the thick filaments. The precise packing of C-protein in the thick filament is still unknown. It is the only sarcomeric protein which binds to both myosin and actin, and the actin-binding is Ca-sensitive. In cardiac and slow, but not fast, skeletal muscles C-protein is phosphorylated. Amino acid composition suggests a protein of little or no αhelical content. Variant forms (isoforms) of C-protein have been identified in cardiac, slow and embryonic muscles.

High resolution spot scan imaging of frozen, hydrated actin bundles with 400kV electrons

1992 ◽  
Vol 50 (1) ◽  
pp. 512-513
Author(s):  
J. Jakana ◽  
M.F. Schmid ◽  
P. Matsudaira ◽  
W. Chiu
Keyword(s):  
High Resolution ◽  
Binding Proteins ◽  
Actin Binding ◽  
Eukaryotic Cells ◽  
Dimensional Structure ◽  
Structural Basis ◽  
Actin Bundle ◽  
Actin Bundles ◽  
3 Dimensional ◽  
Macromolecular Assembly

Actin is a protein found in all eukaryotic cells. In its polymerized form, the cells use it for motility, cytokinesis and for cytoskeletal support. An example of this latter class is the actin bundle in the acrosomal process from the Limulus sperm. The different functions actin performs seem to arise from its interaction with the actin binding proteins. A 3-dimensional structure of this macromolecular assembly is essential to provide a structural basis for understanding this interaction in relationship to its development and functions.

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