Gelsolin-mediated actin filament severing, mechanics, and conformational changes at neutral and acidic pH
Gelsolin is a calcium (Ca2+) dependent, pH sensitive actin-binding protein that regulates actin filament dynamics to remodel the actin cytoskeleton. It is known that gelsolin binding induces conformational changes of actin filaments, leading to filament severing. However, the influence of physiologi...
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| Format: | Article |
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Frontiers Media S.A.
2025-03-01
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| Series: | Frontiers in Soft Matter |
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| Online Access: | https://www.frontiersin.org/articles/10.3389/frsfm.2025.1530439/full |
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| author | Taylor V. Douglas Taylor V. Douglas Claire A. Toland Sydney A. Paulin Nicholas Castaneda Nicholas Castaneda Laurene Tetard Laurene Tetard Ellen H. Kang Ellen H. Kang Ellen H. Kang |
| author_facet | Taylor V. Douglas Taylor V. Douglas Claire A. Toland Sydney A. Paulin Nicholas Castaneda Nicholas Castaneda Laurene Tetard Laurene Tetard Ellen H. Kang Ellen H. Kang Ellen H. Kang |
| author_sort | Taylor V. Douglas |
| collection | DOAJ |
| description | Gelsolin is a calcium (Ca2+) dependent, pH sensitive actin-binding protein that regulates actin filament dynamics to remodel the actin cytoskeleton. It is known that gelsolin binding induces conformational changes of actin filaments, leading to filament severing. However, the influence of physiological conditions, such as pH variations, on gelsolin-mediated filament severing activities, mechanics and conformations remains unclear despite their role in actin-actin interactions. Using Total Internal Reflection Fluorescence (TIRF) microscopy imaging and pyrene fluorescence assays, we demonstrate that filament severing efficiencies by gelsolin are enhanced in acidic conditions. In addition, analysis of filament thermal fluctuations using TIRF reveals that gelsolin binding stiffens actin filaments. Furthermore, we show that gelsolin binding induces conformational changes in filaments by measuring the filament half-pitch using high resolution Atomic Force Microscopy imaging. Together, our results suggest that pH modulation plays a key role in gelsolin-mediated filament severing activities, bending mechanics, and conformational changes, which have implications in many cellular processes including cell motility and morphogenesis. |
| format | Article |
| id | doaj-art-efefeafd0abf43f09f7c9cb73cec33a7 |
| institution | Kabale University |
| issn | 2813-0499 |
| language | English |
| publishDate | 2025-03-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Soft Matter |
| spelling | doaj-art-efefeafd0abf43f09f7c9cb73cec33a72025-08-20T03:39:57ZengFrontiers Media S.A.Frontiers in Soft Matter2813-04992025-03-01510.3389/frsfm.2025.15304391530439Gelsolin-mediated actin filament severing, mechanics, and conformational changes at neutral and acidic pHTaylor V. Douglas0Taylor V. Douglas1Claire A. Toland2Sydney A. Paulin3Nicholas Castaneda4Nicholas Castaneda5Laurene Tetard6Laurene Tetard7Ellen H. Kang8Ellen H. Kang9Ellen H. Kang10NanoScience Technology Center, University of Central Florida, Orlando, FL, United StatesDepartment of Physics, College of Sciences, University of Central Florida, Orlando, FL, United StatesNanoScience Technology Center, University of Central Florida, Orlando, FL, United StatesNanoScience Technology Center, University of Central Florida, Orlando, FL, United StatesNanoScience Technology Center, University of Central Florida, Orlando, FL, United StatesBurnett School of Biomedical Sciences, College of Medicine, University of Central Florda, Orlando, FL, United StatesNanoScience Technology Center, University of Central Florida, Orlando, FL, United StatesDepartment of Physics, College of Sciences, University of Central Florida, Orlando, FL, United StatesNanoScience Technology Center, University of Central Florida, Orlando, FL, United StatesDepartment of Physics, College of Sciences, University of Central Florida, Orlando, FL, United StatesDepartmnet of Material Science and Engineering, College of Engineering and Computer Science University of Central Florida, Orlando, FL, United StatesGelsolin is a calcium (Ca2+) dependent, pH sensitive actin-binding protein that regulates actin filament dynamics to remodel the actin cytoskeleton. It is known that gelsolin binding induces conformational changes of actin filaments, leading to filament severing. However, the influence of physiological conditions, such as pH variations, on gelsolin-mediated filament severing activities, mechanics and conformations remains unclear despite their role in actin-actin interactions. Using Total Internal Reflection Fluorescence (TIRF) microscopy imaging and pyrene fluorescence assays, we demonstrate that filament severing efficiencies by gelsolin are enhanced in acidic conditions. In addition, analysis of filament thermal fluctuations using TIRF reveals that gelsolin binding stiffens actin filaments. Furthermore, we show that gelsolin binding induces conformational changes in filaments by measuring the filament half-pitch using high resolution Atomic Force Microscopy imaging. Together, our results suggest that pH modulation plays a key role in gelsolin-mediated filament severing activities, bending mechanics, and conformational changes, which have implications in many cellular processes including cell motility and morphogenesis.https://www.frontiersin.org/articles/10.3389/frsfm.2025.1530439/fullactin cytoskeletongelsolinseveringbending mechanicsfilament conformationintracellular pH |
| spellingShingle | Taylor V. Douglas Taylor V. Douglas Claire A. Toland Sydney A. Paulin Nicholas Castaneda Nicholas Castaneda Laurene Tetard Laurene Tetard Ellen H. Kang Ellen H. Kang Ellen H. Kang Gelsolin-mediated actin filament severing, mechanics, and conformational changes at neutral and acidic pH Frontiers in Soft Matter actin cytoskeleton gelsolin severing bending mechanics filament conformation intracellular pH |
| title | Gelsolin-mediated actin filament severing, mechanics, and conformational changes at neutral and acidic pH |
| title_full | Gelsolin-mediated actin filament severing, mechanics, and conformational changes at neutral and acidic pH |
| title_fullStr | Gelsolin-mediated actin filament severing, mechanics, and conformational changes at neutral and acidic pH |
| title_full_unstemmed | Gelsolin-mediated actin filament severing, mechanics, and conformational changes at neutral and acidic pH |
| title_short | Gelsolin-mediated actin filament severing, mechanics, and conformational changes at neutral and acidic pH |
| title_sort | gelsolin mediated actin filament severing mechanics and conformational changes at neutral and acidic ph |
| topic | actin cytoskeleton gelsolin severing bending mechanics filament conformation intracellular pH |
| url | https://www.frontiersin.org/articles/10.3389/frsfm.2025.1530439/full |
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