ZFIN ID: ZDB-PUB-200908-7
Keratins and Plakin family cytolinker proteins control the length of epithelial microridge protrusions
Inaba, Y., Chauhan, V., van Loon, A.P., Choudhury, L.S., Sagasti, A.
Date: 2020
Source: eLIFE   9: (Journal)
Registered Authors: Sagasti, Alvaro
Keywords: cell biology, developmental biology, zebrafish
MeSH Terms:
  • Animals
  • Cell Surface Extensions*/chemistry
  • Cell Surface Extensions*/metabolism
  • Epithelial Cells/chemistry
  • Epithelial Cells/cytology
  • Epithelial Cells/metabolism
  • Intermediate Filaments/chemistry
  • Intermediate Filaments/metabolism
  • Keratins*/chemistry
  • Keratins*/metabolism
  • Membrane Proteins/chemistry
  • Membrane Proteins/metabolism
  • Plakins*/chemistry
  • Plakins*/metabolism
  • Protein Precursors/chemistry
  • Protein Precursors/metabolism
  • Skin/cytology
  • Zebrafish
  • Zebrafish Proteins/chemistry
  • Zebrafish Proteins/metabolism
PubMed: 32894222 Full text @ Elife
Actin filaments and microtubules create diverse cellular protrusions, but intermediate filaments, the strongest and most stable cytoskeletal elements, are not known to directly participate in the formation of protrusions. Here we show that keratin intermediate filaments directly regulate the morphogenesis of microridges, elongated protrusions arranged in elaborate maze-like patterns on the surface of mucosal epithelial cells. We found that microridges on zebrafish skin cells contained both actin and keratin filaments. Keratin filaments stabilized microridges, and overexpressing keratins lengthened them. Envoplakin and Periplakin, Plakin family cytolinkers that bind F-actin and keratins, localized to microridges and were required for their morphogenesis. Strikingly, Plakin protein levels directly dictated microridge length. An actin-binding domain of Periplakin was required to initiate microridge morphogenesis, whereas Periplakin-keratin binding was required to elongate microridges. These findings separate microridge morphogenesis into distinct steps, expand our understanding of intermediate filament functions, and identify microridges as protrusions that integrate actin and intermediate filaments.