《细胞》发表论文摘要（英文）
Actin-Bundling Protein TRIOBP Forms Resilient Rootlets of Hair Cell Stereocilia Essential for Hearing
Cell Volume 141 Issue 5 786-798 28 May 2010
10.1016/j.cell.2010.03.049
Authors
Shin-ichiro Kitajiri Takeshi Sakamoto Inna A. Belyantseva Richard J. Goodyear Ruben Stepanyan Ikuko Fujiwara Jonathan E. Bird Saima Riazuddin Sheikh Riazuddin Zubair M. Ahmed Jenny E. Hinshaw James Sellers James R. Bartles John A. Hammer Guy P. Richardson Andrew J. Griffith Gregory I. Frolenkov Thomas B. FriedmanSee
Summary
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 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 crosser in stereocilia. We generated mutant Triobp mice (Triobpex8/ex8) that are profoundly deaf. Stereocilia of Triobpex8/ex8 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.
