Irf6 directly regulates Klf17 in zebrafish periderm and Klf4 in murine oral epithelium, and dominant-negative KLF4 variants are present in patients with cleft lip and palate

Hum Mol Genet. 2016 Feb 15;25(4):766-76. doi: 10.1093/hmg/ddv614. Epub 2015 Dec 21.

Abstract

Non-syndromic (NS) cleft lip with or without cleft palate (CL/P) is a common disorder with a strong genetic underpinning. Genome-wide association studies have detected common variants associated with this disorder, but a large portion of the genetic risk for NSCL/P is conferred by unidentified rare sequence variants. Mutations in IRF6 (Interferon Regulatory Factor 6) and GRHL3 (Grainyhead-like 3) cause Van der Woude syndrome, which includes CL/P. Both genes encode members of a regulatory network governing periderm differentiation in model organisms. Here, we report that Krüppel-like factor 17 (Klf17), like Grhl3, acts downstream of Irf6 in this network in zebrafish periderm. Although Klf17 expression is absent from mammalian oral epithelium, a close homologue, Klf4, is expressed in this tissue and is required for the differentiation of epidermis. Chromosome configuration capture and reporter assays indicated that IRF6 directly regulates an oral-epithelium enhancer of KLF4. To test whether rare missense variants of KLF4 contribute risk for NSCL/P, we sequenced KLF4 in approximately 1000 NSCL/P cases and 300 controls. By one statistical test, missense variants of KLF4 as a group were enriched in cases versus controls. Moreover, two patient-derived KLF4 variants disrupted periderm differentiation upon forced expression in zebrafish embryos, suggesting that they have dominant-negative effect. These results indicate that rare NSCL/P risk variants can be found in members of the gene regulatory network governing periderm differentiation.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Case-Control Studies
  • Cleft Lip / genetics*
  • Cleft Lip / metabolism
  • Cleft Palate / genetics*
  • Cleft Palate / metabolism
  • Female
  • Gene Expression Regulation, Developmental
  • Genetic Predisposition to Disease
  • Genome-Wide Association Study
  • Humans
  • Interferon Regulatory Factors / genetics
  • Interferon Regulatory Factors / metabolism*
  • Kruppel-Like Transcription Factors / genetics*
  • Kruppel-Like Transcription Factors / metabolism*
  • Male
  • Mice
  • Mutation
  • Transcription Factors / genetics
  • Transcription Factors / metabolism
  • Zebrafish
  • Zebrafish Proteins / genetics
  • Zebrafish Proteins / metabolism*

Substances

  • GKLF protein
  • IRF6 protein, zebrafish
  • Interferon Regulatory Factors
  • Kruppel-Like Transcription Factors
  • Transcription Factors
  • Zebrafish Proteins
  • klf4 protein, zebrafish