Compressive and Tensile Deformations Alter ATP Hydrolysis and Phosphate Release Rates in Actin Filaments

2021 ◽  
Author(s):  
Sriramvignesh Mani ◽  
Harshwardhan H. Katkar ◽  
Gregory A. Voth
Keyword(s):  
Actin Filaments ◽  
Atp Hydrolysis ◽  
Release Rates ◽  
Phosphate Release

scholarly journals Novel actin filaments fromBacillus thuringiensisform nanotubules for plasmid DNA segregation

2016 ◽  
Vol 113 (9) ◽  
pp. E1200-E1205 ◽  
Author(s):  
Shimin Jiang ◽  
Akihiro Narita ◽  
David Popp ◽  
Umesh Ghoshdastider ◽  
Lin Jie Lee ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Bacillus Thuringiensis ◽  
Plasmid Dna ◽  
Actin Filaments ◽  
Atp Hydrolysis ◽  
Bacterial Dna ◽  
Phosphate Release ◽  
Dna Segregation ◽  
Eukaryotic Chromosome ◽  
Dynamic Assembly

Here we report the discovery of a bacterial DNA-segregating actin-like protein (BtParM) fromBacillus thuringiensis, which forms novel antiparallel, two-stranded, supercoiled, nonpolar helical filaments, as determined by electron microscopy. TheBtParM filament features of supercoiling and forming antiparallel double-strands are unique within the actin fold superfamily, and entirely different to the straight, double-stranded, polar helical filaments of all other known ParMs and of eukaryotic F-actin. TheBtParM polymers show dynamic assembly and subsequent disassembly in the presence of ATP.BtParR, the DNA-BtParM linking protein, stimulated ATP hydrolysis/phosphate release byBtParM and paired two supercoiledBtParM filaments to form a cylinder, comprised of four strands with inner and outer diameters of 57 Å and 145 Å, respectively. Thus, in this prokaryote, the actin fold has evolved to produce a filament system with comparable features to the eukaryotic chromosome-segregating microtubule.

scholarly journals Structural Basis for Actin Assembly, Activation of ATP Hydrolysis, and Delayed Phosphate Release

Cell ◽  
2010 ◽  
Vol 143 (2) ◽  
pp. 275-287 ◽  
Author(s):  
Kenji Murakami ◽  
Takuo Yasunaga ◽  
Taro Q.P. Noguchi ◽  
Yuki Gomibuchi ◽  
Kien X. Ngo ◽  
...  
Keyword(s):  
Atp Hydrolysis ◽  
Structural Basis ◽  
Actin Assembly ◽  
Phosphate Release

scholarly journals Myosin VI deafness mutation prevents the initiation of processive runs on actin

2015 ◽  
Vol 112 (11) ◽  
pp. E1201-E1209 ◽  
Author(s):  
Olena Pylypenko ◽  
Lin Song ◽  
Ai Shima ◽  
Zhaohui Yang ◽  
Anne M. Houdusse ◽  
...  
Keyword(s):  
Actin Filaments ◽  
Inorganic Phosphate ◽  
Atp Hydrolysis ◽  
Hydrolysis Product ◽  
Actin Binding ◽  
Reverse Direction ◽  
Myosin Vi ◽  
Cardiac Myosin ◽  
Atp Levels

Mutations in the reverse-direction myosin, myosin VI, are associated with deafness in humans and mice. A myosin VI deafness mutation, D179Y, which is in the transducer of the motor, uncoupled the release of the ATP hydrolysis product, inorganic phosphate (Pi), from dependency on actin binding and destroyed the ability of single dimeric molecules to move processively on actin filaments. We observed that processive movement is rescued if ATP is added to the mutant dimer following binding of both heads to actin in the absence of ATP, demonstrating that the mutation selectively destroys the initiation of processive runs at physiological ATP levels. A drug (omecamtiv) that accelerates the actin-activated activity of cardiac myosin was able to rescue processivity of the D179Y mutant dimers at physiological ATP concentrations by slowing the actin-independent release of Pi. Thus, it may be possible to create myosin VI-specific drugs that rescue the function of deafness-causing mutations.

scholarly journals Unraveling the Mystery of ATP Hydrolysis in Actin Filaments

2014 ◽  
Vol 136 (37) ◽  
pp. 13053-13058 ◽  
Author(s):  
Martin McCullagh ◽  
Marissa G. Saunders ◽  
Gregory A. Voth
Keyword(s):  
Actin Filaments ◽  
Atp Hydrolysis

scholarly journals Structures of the substrate-engaged 26S proteasome reveal the mechanisms for ATP hydrolysis-driven translocation

2018 ◽  
Author(s):  
Andres H. de la Peña ◽  
Ellen A. Goodall ◽  
Stephanie N. Gates ◽  
Gabriel C. Lander ◽  
Andreas Martin
Keyword(s):  
Conformational Changes ◽  
Atp Hydrolysis ◽  
26S Proteasome ◽  
Atp Binding ◽  
Conformational States ◽  
Phosphate Release ◽  
Protein Substrates ◽  
Cellular Processes ◽  
Hexameric Atpase ◽  
Central Pore

AbstractThe 26S proteasome is the primary eukaryotic degradation machine and thus critically involved in numerous cellular processes. The hetero-hexameric ATPase motor of the proteasome unfolds and translocates targeted protein substrates into the open gate of a proteolytic core, while a proteasomal deubiquitinase concomitantly removes substrate-attached ubiquitin chains. However, the mechanisms by which ATP hydrolysis drives the conformational changes responsible for these processes have remained elusive. Here we present the cryo-EM structures of four distinct conformational states of the actively ATP-hydrolyzing, substrate-engaged 26S proteasome. These structures reveal how mechanical substrate translocation accelerates deubiquitination, and how ATP-binding, hydrolysis, and phosphate-release events are coordinated within the AAA+ motor to induce conformational changes and propel the substrate through the central pore.

Actin filaments stimulate the Na(+)-K(+)-ATPase

1995 ◽  
Vol 269 (5) ◽  
pp. F637-F643 ◽  
Author(s):  
H. F. Cantiello
Keyword(s):  
Sequence Analysis ◽  
Atpase Activity ◽  
Actin Filaments ◽  
Functional Role ◽  
Atp Hydrolysis ◽  
Rat Kidney ◽  
Alpha Subunit ◽  
Actin Binding ◽  
Binding Domains

In this report, the functional role of actin on Na(+)-K(+)-adenosinetriphosphatase (Na(+)-K(+)-ATPase) activity was explored. The Na(+)- and K(+)-dependent, ouabain-sensitive ATP hydrolysis mediated by rat kidney Na(+)-K(+)-ATPase increased by 74% in the presence of previously unpolymerized actin (24 microM), whereas addition of polymerized actin was without effect. Addition of actin was associated instead with an increase in the affinity of the Na(+)-K(+)-ATPase for Na+ but not other enzymatic substates. A maximal stimulatory effect (296%) was observed either at an Na(+)-K(+)-ATPase:actin ratio of 1:50,000 or at lower ratios (1:625) by shifting from the E2 (K+ selective) to the E1 (Na+ selective) conformation of the enzyme. Immunoblotting of actin to the purified Na(+)-K(+)-ATPase suggested that this interaction may be linked to binding of actin to the enzyme, which was further supported by sequence analysis indicating putative actin-binding domains in the alpha-subunit of the enzyme. The interaction between actin and the Na(+)-K(+)-ATPase may imply a novel functional role of the cytoskeleton in the control of ion transport.

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