Fascin 2b is a component of stereocilia that lengthens actin-based protrusions

Autor: Lana M. Pollock, Gustavo Gomez, Shih Wei Chou, Carol A. Fernando, Beth Burnside, Brian M. McDermott, Philsang Hwang, Megan C. West, Jennifer Lin-Jones
Přispěvatelé: May, Robin Charles
Jazyk: angličtina
Rok vydání: 2011
Předmět:
Stereocilia (inner ear)
Messenger
lcsh:Medicine
Animals
Genetically Modified
Otolaryngology
0302 clinical medicine
Chlorocebus aethiops
Serine
Site-Directed
Pseudopodia
Mechanotransduction
Phosphorylation
Cytoskeleton
lcsh:Science
Zebrafish
Auditory
0303 health sciences
Multidisciplinary
biology
Developmental Biology/Morphogenesis and Cell Biology
Microfilament Proteins
3. Good health
Cell biology
Protein Transport
Hair Cells
COS Cells
Filopodia
Research Article
General Science & Technology
Genetically Modified
macromolecular substances
Filamentous actin
03 medical and health sciences
Cell Biology/Cytoskeleton
Hair Cells
Auditory
otorhinolaryngologic diseases
Animals
RNA
Messenger
Cilia
Eye Proteins
Eye Disease and Disorders of Vision
Actin
030304 developmental biology
Fascin
Neuroscience/Sensory Systems
lcsh:R
Neurosciences
biology.organism_classification
Phosphoproteins
Actins
Mutagenesis
Mutation
biology.protein
Mutagenesis
Site-Directed
RNA
lcsh:Q
sense organs
030217 neurology & neurosurgery
Zdroj: PLoS ONE, Vol 6, Iss 4, p e14807 (2011)
PloS one, vol 6, iss 4
PLoS ONE
ISSN: 1932-6203
Popis: 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.
Databáze: OpenAIRE
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