TY - JOUR
T1 - Plastin 1 widens stereocilia by transforming actin filament packing from hexagonal to liquid
AU - Krey, Jocelyn F.
AU - Krystofiak, Evan S.
AU - Dumont, Rachel A.
AU - Vijayakumar, Sarath
AU - Choi, Dongseok
AU - Rivero, Francisco
AU - Kachar, Bechara
AU - Jones, Sherri M.
AU - Barr-Gillespie, Peter G.
N1 - Publisher Copyright:
© 2016 Krey et al.
PY - 2016
Y1 - 2016
N2 - With their essential role in inner ear function, stereocilia of sensory hair cells demonstrate the importance of cellular actin protrusions. Actin packing in stereocilia is mediated by cross-linkers of the plastin, fascin, and espin families. Although mice lacking espin (ESPN) have no vestibular or auditory function, we found that mice that either lacked plastin 1 (PLS1) or had nonfunctional fascin 2 (FSCN2) had reduced inner ear function, with double-mutant mice most strongly affected. Targeted mass spectrometry indicated that PLS1 was the most abundant cross-linker in vestibular stereocilia and the second most abundant protein overall; ESPN only accounted for ~15% of the total cross-linkers in bundles. Mouse utricle stereocilia lacking PLS1 were shorter and thinner than wild-type stereocilia. Surprisingly, although wild-type stereocilia had random liquid packing of their actin filaments, stereocilia lacking PLS1 had orderly hexagonal packing. Although all three cross-linkers are required for stereocilia structure and function, PLS1 biases actin toward liquid packing, which allows stereocilia to grow to a greater diameter.
AB - With their essential role in inner ear function, stereocilia of sensory hair cells demonstrate the importance of cellular actin protrusions. Actin packing in stereocilia is mediated by cross-linkers of the plastin, fascin, and espin families. Although mice lacking espin (ESPN) have no vestibular or auditory function, we found that mice that either lacked plastin 1 (PLS1) or had nonfunctional fascin 2 (FSCN2) had reduced inner ear function, with double-mutant mice most strongly affected. Targeted mass spectrometry indicated that PLS1 was the most abundant cross-linker in vestibular stereocilia and the second most abundant protein overall; ESPN only accounted for ~15% of the total cross-linkers in bundles. Mouse utricle stereocilia lacking PLS1 were shorter and thinner than wild-type stereocilia. Surprisingly, although wild-type stereocilia had random liquid packing of their actin filaments, stereocilia lacking PLS1 had orderly hexagonal packing. Although all three cross-linkers are required for stereocilia structure and function, PLS1 biases actin toward liquid packing, which allows stereocilia to grow to a greater diameter.
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U2 - 10.1083/jcb.201606036
DO - 10.1083/jcb.201606036
M3 - Article
C2 - 27811163
AN - SCOPUS:85003989012
SN - 0021-9525
VL - 215
SP - 467
EP - 482
JO - Journal of Cell Biology
JF - Journal of Cell Biology
IS - 4
ER -