ZFIN ID: ZDB-PUB-140303-13
ACF7 is a hair-bundle antecedent, positioned to integrate cuticular plate actin and somatic tubulin
Antonellis, P.J., Pollock, L.M., Chou, S.W., Hassan, A., Geng, R., Chen, X., Fuchs, E., Alagramam, K.N., Auer, M., and McDermott, B.M.
Date: 2014
Source: The Journal of neuroscience : the official journal of the Society for Neuroscience   34(1): 305-312 (Journal)
Registered Authors: Antonellis, Patrick, Chou, Shih-wei, McDermott Jr., Brian M., Pollock, Lana
Keywords: none
MeSH Terms:
  • Acoustic Maculae
  • Actins/analysis*
  • Actins/ultrastructure
  • Animals
  • Animals, Genetically Modified
  • Chickens
  • Cytoskeleton/chemistry
  • Cytoskeleton/ultrastructure
  • Female
  • Hair Cells, Auditory/chemistry*
  • Hair Cells, Auditory/ultrastructure
  • Male
  • Mice
  • Microfilament Proteins/analysis*
  • Microfilament Proteins/ultrastructure
  • Species Specificity
  • Tubulin/analysis*
  • Tubulin/ultrastructure
  • Zebrafish
PubMed: 24381291 Full text @ J. Neurosci.
FIGURES
ABSTRACT

The precise morphology of the mechanosensitive hair bundle requires seamless integration of actin and microtubule networks. Here, we identify Acf7a (actin crosslinking family protein 7a) as a protein positioned to bridge these distinct cytoskeletal networks in hair cells. By imaging Acf7a–Citrine fusion protein in zebrafish and immunolabeling of vestibular and cochlear mouse hair cells, we show that Acf7a and ACF7 circumscribe, underlie, and are interwoven into the cuticular plate (CP), and they also encircle the basal body of the kinocilium. In cochlear hair cells, ACF7 localization is graded, with the highest concentration near each fonticulus—an area free of F-actin in the region of the CP that contains the basal body. During hair-cell development and regeneration, Acf7a precedes formation of the hair bundle and CP. Finally, electron tomography demonstrates that the ends of microtubules insert into the CP and are decorated with filamentous linkers connecting microtubules to the CP. These observations are consistent with ACF7 being a linker protein, which may shape the cytoskeleton of the hair cell early during hair-bundle genesis.

ADDITIONAL INFORMATION