Details

Autor(en) / Beteiligte

• Cao, Huiren
• Yin, Xiaolei
• Cao, Yujie
• Jin, Yecheng
• Wang, Shan
• Kong, Yanhui
• Chen, Yuexing
• Gao, Jiangang
• Heller, Stefan
• Xu, Zhigang
• Koch, Karl-Wilhelm

Titel

FCHSD1 and FCHSD2 are expressed in hair cell stereocilia and cuticular plate and regulate actin polymerization in vitro

Ist Teil von

• PloS one, 2013-02, Vol.8 (2), p.e56516-e56516

Ort / Verlag

United States: Public Library of Science

Erscheinungsjahr

2013

Quelle

MEDLINE

Beschreibungen/Notizen

• Mammalian FCHSD1 and FCHSD2 are homologous proteins containing an amino-terminal F-BAR domain and two SH3 domains near their carboxyl-termini. We report here that FCHSD1 and FCHSD2 are expressed in mouse cochlear sensory hair cells. FCHSD1 mainly localizes to the cuticular plate, whereas FCHSD2 mainly localizes along the stereocilia in a punctuate pattern. Nervous Wreck (Nwk), the Drosophila ortholog of FCHSD1 and FCHSD2, has been shown to bind Wsp and play an important role in F-actin assembly. We show that, like its Drosophila counterpart, FCHSD2 interacts with WASP and N-WASP, the mammalian orthologs of Drosophila Wsp, and stimulates F-actin assembly in vitro. In contrast, FCHSD1 doesn't bind WASP or N-WASP, and can't stimulate F-actin assembly when tested in vitro. We found, however, that FCHSD1 binds via its F-BAR domain to the SH3 domain of Sorting Nexin 9 (SNX9), a well characterized BAR protein that has been shown to promote WASP-Arp2/3-dependent F-actin polymerization. FCHSD1 greatly enhances SNX9's WASP-Arp2/3-dependent F-actin polymerization activity. In hair cells, SNX9 was detected in the cuticular plate, where it colocalizes with FCHSD1. Our results suggest that FCHSD1 and FCHSD2 could modulate F-actin assembly or maintenance in hair cell stereocilia and cuticular plate.