Live-cell Imaging of Actin Dynamics Reveals Mechanisms of Stereocilia Length Regulation in the Inner Ear

Overview

Journal Nat Commun

Specialty Biology

Date 2015 Apr 22

PMID 25898120

Citations 45

Authors

Meghan C Drummond

Melanie Barzik

Jonathan E Bird

Duan-Sun Zhang

Claude P Lechene

David P Corey

Lisa L Cunningham

Thomas B Friedman

Affiliations

Soon will be listed here.

Abstract

The maintenance of sensory hair cell stereocilia is critical for lifelong hearing; however, mechanisms of structural homeostasis remain poorly understood. Conflicting models propose that stereocilia F-actin cores are either continually renewed every 24-48 h via a treadmill or are stable, exceptionally long-lived structures. Here to distinguish between these models, we perform an unbiased survey of stereocilia actin dynamics in more than 500 utricle hair cells. Live-imaging EGFP-β-actin or dendra2-β-actin reveal stable F-actin cores with turnover and elongation restricted to stereocilia tips. Fixed-cell microscopy of wild-type and mutant β-actin demonstrates that incorporation of actin monomers into filaments is required for localization to stereocilia tips. Multi-isotope imaging mass spectrometry and live imaging of single differentiating hair cells capture stereociliogenesis and explain uniform incorporation of (15)N-labelled protein and EGFP-β-actin into nascent stereocilia. Collectively, our analyses support a model in which stereocilia actin cores are stable structures that incorporate new F-actin only at the distal tips.

Citing Articles

A Myosin Nanomotor Essential for Stereocilia Maintenance Expands the Etiology of Hereditary Hearing Loss DFNB3.

Behnammanesh G, Dragich A, Liao X, Hadi S, Kim M, Perrin B bioRxiv. 2025; .

PMID: 40027801 PMC: 11870491. DOI: 10.1101/2025.02.19.639121.

Myosin-based nucleation of actin filaments contributes to stereocilia development critical for hearing.

Moreland Z, Jiang F, Aguilar C, Barzik M, Gong R, Behnammanesh G Nat Commun. 2025; 16(1):947.

PMID: 39843411 PMC: 11754657. DOI: 10.1038/s41467-025-55898-8.

Myosin-dependent short actin filaments contribute to peripheral widening in developing stereocilia.

Liao X, Tung C, Krey J, Behnammanesh G, Cirilo Jr J, Colpan M Res Sq. 2024; .

PMID: 39678325 PMC: 11643313. DOI: 10.21203/rs.3.rs-5448262/v1.

Information processing at the speed of light.

AbuGhanem M Front Optoelectron. 2024; 17(1):33.

PMID: 39342550 PMC: 11439970. DOI: 10.1007/s12200-024-00133-3.

Proteins required for stereocilia elongation during mammalian hair cell development ensure precise and steady heights during adult life.

Hartig E, Day M, Jarysta A, Tarchini B Proc Natl Acad Sci U S A. 2024; 121(40):e2405455121.

PMID: 39320919 PMC: 11459194. DOI: 10.1073/pnas.2405455121.

References

Wegner A . Head to tail polymerization of actin. J Mol Biol. 1976; 108(1):139-50. DOI: 10.1016/s0022-2836(76)80100-3. View

Ridley A . Life at the leading edge. Cell. 2011; 145(7):1012-22. DOI: 10.1016/j.cell.2011.06.010. View

Frolenkov G, Belyantseva I, Friedman T, Griffith A . Genetic insights into the morphogenesis of inner ear hair cells. Nat Rev Genet. 2004; 5(7):489-98. DOI: 10.1038/nrg1377. View

Fujiwara I, Takahashi S, Tadakuma H, Funatsu T, Ishiwata S . Microscopic analysis of polymerization dynamics with individual actin filaments. Nat Cell Biol. 2002; 4(9):666-73. DOI: 10.1038/ncb841. View

Shin J, Longo-Guess C, Gagnon L, Saylor K, Dumont R, Spinelli K . The R109H variant of fascin-2, a developmentally regulated actin crosslinker in hair-cell stereocilia, underlies early-onset hearing loss of DBA/2J mice. J Neurosci. 2010; 30(29):9683-94. PMC: 2922854. DOI: 10.1523/JNEUROSCI.1541-10.2010. View

Tilney L, DeRosier D, Mulroy M . The organization of actin filaments in the stereocilia of cochlear hair cells. J Cell Biol. 1980; 86(1):244-59. PMC: 2110658. DOI: 10.1083/jcb.86.1.244. View

Monzack E, Cunningham L . Lead roles for supporting actors: critical functions of inner ear supporting cells. Hear Res. 2013; 303:20-9. PMC: 3648608. DOI: 10.1016/j.heares.2013.01.008. View

Nayak G, Ratnayaka H, Goodyear R, Richardson G . Development of the hair bundle and mechanotransduction. Int J Dev Biol. 2007; 51(6-7):597-608. DOI: 10.1387/ijdb.072392gn. View

May L, Kramarenko I, Brandon C, Voelkel-Johnson C, Roy S, Truong K . Inner ear supporting cells protect hair cells by secreting HSP70. J Clin Invest. 2013; 123(8):3577-87. PMC: 3967657. DOI: 10.1172/JCI68480. View

10.

Pollard T, Borisy G . Cellular motility driven by assembly and disassembly of actin filaments. Cell. 2003; 112(4):453-65. DOI: 10.1016/s0092-8674(03)00120-x. View

11.

Toyama B, Hetzer M . Protein homeostasis: live long, won't prosper. Nat Rev Mol Cell Biol. 2012; 14(1):55-61. PMC: 3570024. DOI: 10.1038/nrm3496. View

12.

Schneider M, Belyantseva I, Azevedo R, Kachar B . Rapid renewal of auditory hair bundles. Nature. 2002; 418(6900):837-8. DOI: 10.1038/418837a. View

13.

Beurg M, Fettiplace R, Nam J, Ricci A . Localization of inner hair cell mechanotransducer channels using high-speed calcium imaging. Nat Neurosci. 2009; 12(5):553-8. PMC: 2712647. DOI: 10.1038/nn.2295. View

14.

Daudet N, Lebart M . Transient expression of the t-isoform of plastins/fimbrin in the stereocilia of developing auditory hair cells. Cell Motil Cytoskeleton. 2002; 53(4):326-36. DOI: 10.1002/cm.10092. View

15.

Posern G, Sotiropoulos A, Treisman R . Mutant actins demonstrate a role for unpolymerized actin in control of transcription by serum response factor. Mol Biol Cell. 2002; 13(12):4167-78. PMC: 138624. DOI: 10.1091/mbc.02-05-0068. View

16.

Indzhykulian A, Stepanyan R, Nelina A, Spinelli K, Ahmed Z, Belyantseva I . Molecular remodeling of tip links underlies mechanosensory regeneration in auditory hair cells. PLoS Biol. 2013; 11(6):e1001583. PMC: 3679001. DOI: 10.1371/journal.pbio.1001583. View

17.

Furness D, Mahendrasingam S, Ohashi M, Fettiplace R, Hackney C . The dimensions and composition of stereociliary rootlets in mammalian cochlear hair cells: comparison between high- and low-frequency cells and evidence for a connection to the lateral membrane. J Neurosci. 2008; 28(25):6342-53. PMC: 2989617. DOI: 10.1523/JNEUROSCI.1154-08.2008. View

18.

Zhang D, Piazza V, Perrin B, Rzadzinska A, Poczatek J, Wang M . Multi-isotope imaging mass spectrometry reveals slow protein turnover in hair-cell stereocilia. Nature. 2012; 481(7382):520-4. PMC: 3267870. DOI: 10.1038/nature10745. View

19.

Bugyi B, Carlier M . Control of actin filament treadmilling in cell motility. Annu Rev Biophys. 2010; 39:449-70. DOI: 10.1146/annurev-biophys-051309-103849. View

20.

Sankaranarayanan S, Atluri P, Ryan T . Actin has a molecular scaffolding, not propulsive, role in presynaptic function. Nat Neurosci. 2003; 6(2):127-35. DOI: 10.1038/nn1002. View