actomyosin contractility Dotaz Zobrazit nápovědu
Constriction of the cytokinetic ring, a circular structure of actin filaments, is an essential step during cell division. Mechanical forces driving the constriction are attributed to myosin motor proteins, which slide actin filaments along each other. However, in multiple organisms, ring constriction has been reported to be myosin independent. How actin rings constrict in the absence of motor activity remains unclear. Here, we demonstrate that anillin, a non-motor actin crosslinker, indispensable during cytokinesis, autonomously propels the contractility of actin bundles. Anillin generates contractile forces of tens of pico-Newtons to maximise the lengths of overlaps between bundled actin filaments. The contractility is enhanced by actin disassembly. When multiple actin filaments are arranged into a ring, this contractility leads to ring constriction. Our results indicate that passive actin crosslinkers can substitute for the activity of molecular motors to generate contractile forces in a variety of actin networks, including the cytokinetic ring.
- MeSH
- aktiny metabolismus MeSH
- aktomyosin metabolismus MeSH
- buněčné dělení MeSH
- cytokineze MeSH
- Drosophila melanogaster metabolismus MeSH
- kontraktilní proteiny genetika metabolismus MeSH
- lidé MeSH
- mikrofilamenta metabolismus MeSH
- mikrofilamentové proteiny MeSH
- myosiny metabolismus MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- MeSH
- aktiny fyziologie genetika MeSH
- cytoskelet fyziologie MeSH
- cytoskeletální proteiny * fyziologie genetika MeSH
- kontrakce myokardu * fyziologie MeSH
- kontraktilní proteiny fyziologie MeSH
- lidé MeSH
- myosiny fyziologie genetika MeSH
- protein - isoformy MeSH
- svalové proteiny * fyziologie genetika metabolismus MeSH
- tropomodulin fyziologie genetika MeSH
- tropomyosin fyziologie genetika MeSH
- troponin fyziologie genetika MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- práce podpořená grantem MeSH
- přehledy MeSH
The aim of this study was to analyze the effects of chronic administration of the ß-adrenoceptor agonist clenbuterol (2 mg/kg body weight/day for a period of 30 days) on the major contractile protein (myosin) in the left ventricular muscle of the adult mouse heart. Separation of myosin heavy chain (MHC) isoforms on 7.5 % glycerol SDS-PAGE and subsequent quantification of the gels by laser densitometry showed a 6.5-fold increase in the ß-isoform of MHC in the clenbuterol-treated group. The ?: ß ratio of these two isoforms in the control group was 98.16±0.14 %: 1.83±0.14 %, whereas in the treated group it was 88.05±1.15 %: 11.95±1.15 %. Actomyosin ATPase activity assay demonstrated a significant (20 %) decline in ATPase activity of the tissue in the ß-agonist-treated group. These results suggest that chronic clenbuterol treatment is capable to induced the transformation of MHC isoforms increasing the slow ß-MHC isoform, which may contribute to the altered contractile mechanics of clenbuterol-treated hearts.
- MeSH
- aktomyosin chemie izolace a purifikace MeSH
- dysfunkce levé srdeční komory etiologie farmakoterapie MeSH
- finanční podpora výzkumu jako téma MeSH
- index tělesné hmotnosti MeSH
- klenbuterol aplikace a dávkování terapeutické užití MeSH
- kontrakce myokardu účinky záření MeSH
- myši metabolismus růst a vývoj MeSH
- těžké řetězce myosinu chemie MeSH
- zvířata MeSH
- Check Tag
- myši metabolismus růst a vývoj MeSH
- zvířata MeSH
- MeSH
- kontrakce myokardu MeSH
- myosiny fyziologie metabolismus MeSH
- Publikační typ
- přehledy MeSH
