Actin-bundling protein TRIOBP forms resilient rootlets of hair cell stereocilia essential for hearing.
Cell
; 141(5): 786-98, 2010 May 28.
Article
em En
| MEDLINE
| ID: mdl-20510926
ABSTRACT
Inner ear hair cells detect sound through deflection of mechanosensory stereocilia. Each stereocilium is supported by a paracrystalline array of parallel actin filaments that are packed more densely at the base, forming a rootlet extending into the cell body. The function of rootlets and the molecules responsible for their formation are unknown. We found that TRIOBP, a cytoskeleton-associated protein mutated in human hereditary deafness DFNB28, is localized to rootlets. In vitro, purified TRIOBP isoform 4 protein organizes actin filaments into uniquely dense bundles reminiscent of rootlets but distinct from bundles formed by espin, an actin crosslinker in stereocilia. We generated mutant Triobp mice (Triobp(Deltaex8/Deltaex8)) that are profoundly deaf. Stereocilia of Triobp(Deltaex8/Deltaex8) mice develop normally but fail to form rootlets and are easier to deflect and damage. Thus, F-actin bundling by TRIOBP provides durability and rigidity for normal mechanosensitivity of stereocilia and may contribute to resilient cytoskeletal structures elsewhere.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Citoesqueleto de Actina
/
Surdez
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Células Ciliadas Auditivas Internas
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Proteínas dos Microfilamentos
Limite:
Animals
/
Humans
Idioma:
En
Revista:
Cell
Ano de publicação:
2010
Tipo de documento:
Article
País de afiliação:
Estados Unidos