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Mutations in the SH1 helix alter the thermal properties of myosin II
The myosin II SH1 helix is a joint that links the converter subdomain to the rest of the myosin motor domain and possibly plays a key role in the arrangement of the converter/lever arm. Several point mutations within the SH1 helix in human myosin IIs have been shown to cause diseases. To reveal whet...
Autores principales: | , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
The Biophysical Society of Japan (BSJ)
2017
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5468464/ https://www.ncbi.nlm.nih.gov/pubmed/28630813 http://dx.doi.org/10.2142/biophysico.14.0_67 |
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author | Shibata, Kotomi Koyama, Tsubasa Inde, Shohei Iwai, Sosuke Chaen, Shigeru |
author_facet | Shibata, Kotomi Koyama, Tsubasa Inde, Shohei Iwai, Sosuke Chaen, Shigeru |
author_sort | Shibata, Kotomi |
collection | PubMed |
description | The myosin II SH1 helix is a joint that links the converter subdomain to the rest of the myosin motor domain and possibly plays a key role in the arrangement of the converter/lever arm. Several point mutations within the SH1 helix in human myosin IIs have been shown to cause diseases. To reveal whether these SH1 helix mutations affect not only motile activities but also thermal properties of myosin II, here we introduced the E683K or R686C point mutation into the SH1 helix in Dictyostelium myosin II. Thermal inactivation as well as thermal aggregation rates of these mutant proteins demonstrated that these mutations decreased the thermal stability of myosin II. Temperature dependence of sliding velocities of actin filaments showed that these mutations also reduced the activation energy of a rate-limiting process involved in actin movement. Given that these mutations are likely to alter coupling between the subdomains, and thus their thermal fluctuations, we propose that the SH1 helix is a key structural element that determines the flexibility and thermal properties of the myosin motor. These characteristics of the SH1 helix may contribute to the pathogenesis of the human diseases caused by mutations within this structural element. |
format | Online Article Text |
id | pubmed-5468464 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2017 |
publisher | The Biophysical Society of Japan (BSJ) |
record_format | MEDLINE/PubMed |
spelling | pubmed-54684642017-06-19 Mutations in the SH1 helix alter the thermal properties of myosin II Shibata, Kotomi Koyama, Tsubasa Inde, Shohei Iwai, Sosuke Chaen, Shigeru Biophys Physicobiol Regular Article The myosin II SH1 helix is a joint that links the converter subdomain to the rest of the myosin motor domain and possibly plays a key role in the arrangement of the converter/lever arm. Several point mutations within the SH1 helix in human myosin IIs have been shown to cause diseases. To reveal whether these SH1 helix mutations affect not only motile activities but also thermal properties of myosin II, here we introduced the E683K or R686C point mutation into the SH1 helix in Dictyostelium myosin II. Thermal inactivation as well as thermal aggregation rates of these mutant proteins demonstrated that these mutations decreased the thermal stability of myosin II. Temperature dependence of sliding velocities of actin filaments showed that these mutations also reduced the activation energy of a rate-limiting process involved in actin movement. Given that these mutations are likely to alter coupling between the subdomains, and thus their thermal fluctuations, we propose that the SH1 helix is a key structural element that determines the flexibility and thermal properties of the myosin motor. These characteristics of the SH1 helix may contribute to the pathogenesis of the human diseases caused by mutations within this structural element. The Biophysical Society of Japan (BSJ) 2017-05-31 /pmc/articles/PMC5468464/ /pubmed/28630813 http://dx.doi.org/10.2142/biophysico.14.0_67 Text en 2017 © The Biophysical Society of Japan |
spellingShingle | Regular Article Shibata, Kotomi Koyama, Tsubasa Inde, Shohei Iwai, Sosuke Chaen, Shigeru Mutations in the SH1 helix alter the thermal properties of myosin II |
title | Mutations in the SH1 helix alter the thermal properties of myosin II |
title_full | Mutations in the SH1 helix alter the thermal properties of myosin II |
title_fullStr | Mutations in the SH1 helix alter the thermal properties of myosin II |
title_full_unstemmed | Mutations in the SH1 helix alter the thermal properties of myosin II |
title_short | Mutations in the SH1 helix alter the thermal properties of myosin II |
title_sort | mutations in the sh1 helix alter the thermal properties of myosin ii |
topic | Regular Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5468464/ https://www.ncbi.nlm.nih.gov/pubmed/28630813 http://dx.doi.org/10.2142/biophysico.14.0_67 |
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