Fascin 2b Is a Component of Stereocilia that Lengthens Actin-Based Protrusions
Stereocilia are actin-filled protrusions that permit mechanotransduction in the internal ear. To identify proteins that organize the cytoskeleton of stereocilia, we scrutinized the hair-cell transcriptome of zebrafish. One promising candidate encodes fascin 2b, a filamentous actin-bundling protein f...
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| Format: | Online |
| Language: | English |
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Public Library of Science
2011
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| Online Access: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3082522/ |
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pubmed-30825222011-05-27 Fascin 2b Is a Component of Stereocilia that Lengthens Actin-Based Protrusions Chou, Shih-Wei Hwang, Philsang Gomez, Gustavo Fernando, Carol A. West, Megan C. Pollock, Lana M. Lin-Jones, Jennifer Burnside, Beth McDermott, Brian M. Research Article Stereocilia are actin-filled protrusions that permit mechanotransduction in the internal ear. To identify proteins that organize the cytoskeleton of stereocilia, we scrutinized the hair-cell transcriptome of zebrafish. One promising candidate encodes fascin 2b, a filamentous actin-bundling protein found in retinal photoreceptors. Immunolabeling of zebrafish hair cells and the use of transgenic zebrafish that expressed fascin 2b fused to green fluorescent protein demonstrated that fascin 2b localized to stereocilia specifically. When filamentous actin and recombinant fusion protein containing fascin 2b were combined in vitro to determine their dissociation constant, a K d≈0.37 µM was observed. Electron microscopy showed that fascin 2b-actin filament complexes formed parallel actin bundles in vitro. We demonstrated that expression of fascin 2b or espin, another actin-bundling protein, in COS-7 cells induced the formation of long filopodia. Coexpression showed synergism between these proteins through the formation of extra-long protrusions. Using phosphomutant fascin 2b proteins, which mimicked either a phosphorylated or a nonphosphorylated state, in COS-7 cells and in transgenic hair cells, we showed that both formation of long filopodia and localization of fascin 2b to stereocilia were dependent on serine 38. Overexpression of wild-type fascin 2b in hair cells was correlated with increased stereociliary length relative to controls. These findings indicate that fascin 2b plays a key role in shaping stereocilia. Public Library of Science 2011-04-26 /pmc/articles/PMC3082522/ /pubmed/21625653 http://dx.doi.org/10.1371/journal.pone.0014807 Text en Chou et al. http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are properly credited. |
| repository_type |
Open Access Journal |
| institution_category |
Foreign Institution |
| institution |
US National Center for Biotechnology Information |
| building |
NCBI PubMed |
| collection |
Online Access |
| language |
English |
| format |
Online |
| author |
Chou, Shih-Wei Hwang, Philsang Gomez, Gustavo Fernando, Carol A. West, Megan C. Pollock, Lana M. Lin-Jones, Jennifer Burnside, Beth McDermott, Brian M. |
| spellingShingle |
Chou, Shih-Wei Hwang, Philsang Gomez, Gustavo Fernando, Carol A. West, Megan C. Pollock, Lana M. Lin-Jones, Jennifer Burnside, Beth McDermott, Brian M. Fascin 2b Is a Component of Stereocilia that Lengthens Actin-Based Protrusions |
| author_facet |
Chou, Shih-Wei Hwang, Philsang Gomez, Gustavo Fernando, Carol A. West, Megan C. Pollock, Lana M. Lin-Jones, Jennifer Burnside, Beth McDermott, Brian M. |
| author_sort |
Chou, Shih-Wei |
| title |
Fascin 2b Is a Component of Stereocilia that Lengthens Actin-Based
Protrusions |
| title_short |
Fascin 2b Is a Component of Stereocilia that Lengthens Actin-Based
Protrusions |
| title_full |
Fascin 2b Is a Component of Stereocilia that Lengthens Actin-Based
Protrusions |
| title_fullStr |
Fascin 2b Is a Component of Stereocilia that Lengthens Actin-Based
Protrusions |
| title_full_unstemmed |
Fascin 2b Is a Component of Stereocilia that Lengthens Actin-Based
Protrusions |
| title_sort |
fascin 2b is a component of stereocilia that lengthens actin-based
protrusions |
| description |
Stereocilia are actin-filled protrusions that permit mechanotransduction in the
internal ear. To identify proteins that organize the cytoskeleton of
stereocilia, we scrutinized the hair-cell transcriptome of zebrafish. One
promising candidate encodes fascin 2b, a filamentous actin-bundling protein
found in retinal photoreceptors. Immunolabeling of zebrafish hair cells and the
use of transgenic zebrafish that expressed fascin 2b fused to green fluorescent
protein demonstrated that fascin 2b localized to stereocilia specifically. When
filamentous actin and recombinant fusion protein containing fascin 2b were
combined in vitro to determine their dissociation constant, a
K
d≈0.37 µM was observed. Electron
microscopy showed that fascin 2b-actin filament complexes formed parallel actin
bundles in vitro. We demonstrated that expression of fascin 2b
or espin, another actin-bundling protein, in COS-7 cells induced the formation
of long filopodia. Coexpression showed synergism between these proteins through
the formation of extra-long protrusions. Using phosphomutant fascin 2b proteins,
which mimicked either a phosphorylated or a nonphosphorylated state, in COS-7
cells and in transgenic hair cells, we showed that both formation of long
filopodia and localization of fascin 2b to stereocilia were dependent on serine
38. Overexpression of wild-type fascin 2b in hair cells was correlated with
increased stereociliary length relative to controls. These findings indicate
that fascin 2b plays a key role in shaping stereocilia. |
| publisher |
Public Library of Science |
| publishDate |
2011 |
| url |
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3082522/ |
| _version_ |
1611450488655446016 |