Keratin 14-dependent disulfides regulate epidermal homeostasis and barrier function via 14-3-3σ and YAP1

Elife. 2020 May 5;9:e53165. doi: 10.7554/eLife.53165.

Abstract

The intermediate filament protein keratin 14 (K14) provides vital structural support in basal keratinocytes of epidermis. Recent studies evidenced a role for K14-dependent disulfide bonding in the organization and dynamics of keratin IFs in skin keratinocytes. Here we report that knock-in mice harboring a cysteine-to-alanine substitution at Krt14's codon 373 (C373A) exhibit alterations in disulfide-bonded K14 species and a barrier defect secondary to enhanced proliferation, faster transit time and altered differentiation in epidermis. A proteomics screen identified 14-3-3 as K14 interacting proteins. Follow-up studies showed that YAP1, a transcriptional effector of Hippo signaling regulated by 14-3-3sigma in skin keratinocytes, shows aberrant subcellular partitioning and function in differentiating Krt14 C373A keratinocytes. Residue C373 in K14, which is conserved in a subset of keratins, is revealed as a novel regulator of keratin organization and YAP function in early differentiating keratinocytes, with an impact on cell mechanics, homeostasis and barrier function in epidermis.

Keywords: 14-3-3; cell biology; epidermis; hippo; intermediate filament; keratinocyte; mouse; skin.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • 14-3-3 Proteins / metabolism*
  • 14-3-3 Proteins / physiology
  • Adaptor Proteins, Signal Transducing / metabolism*
  • Adaptor Proteins, Signal Transducing / physiology
  • Animals
  • Cell Cycle Proteins / metabolism*
  • Cell Cycle Proteins / physiology
  • Epidermis / metabolism*
  • Epidermis / physiology
  • Epidermis / ultrastructure
  • Female
  • Gene Knock-In Techniques
  • Homeostasis
  • Keratin-14 / metabolism*
  • Keratin-14 / physiology
  • Keratinocytes / metabolism
  • Keratinocytes / physiology
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Microscopy, Electron, Transmission
  • YAP-Signaling Proteins

Substances

  • 14-3-3 Proteins
  • Adaptor Proteins, Signal Transducing
  • Cell Cycle Proteins
  • Keratin-14
  • Krt14 protein, mouse
  • Sfn protein, mouse
  • YAP-Signaling Proteins
  • Yap1 protein, mouse