Identification of a DYRK1A-mediated phosphorylation site within the nuclear localization sequence of the hedgehog transcription factor GLI1

Biochem Biophys Res Commun. 2017 Sep 23;491(3):767-772. doi: 10.1016/j.bbrc.2017.07.107. Epub 2017 Jul 20.

Abstract

GLI1 is a key downstream transcription effector of the Hedgehog (Hh) signaling pathway that is involved in promoting cell growth, differentiation and tissue patterning in embryonic development. GLI1 over-activation and its nuclear localization has also been linked to the increased aggressiveness of a number of cancers. It has previously been demonstrated that DYRK1A (dual-specificity tyrosine-regulated kinase 1A) can phosphorylate GLI1 and promote GLI1 nuclear localization and its transcriptional activity. Utilizing recombinant human GLI1 and DYRK1A proteins and phospho-peptide mass spectrometry, we demonstrated that GLI1 is phosphorylated by DYRK1A at Ser408, a phospho-site that falls within the putative nuclear localization sequence (NLS) of GLI1, suggesting a possible mechanistic role in modulating its translocation. Further, we showed that the Ser408 site on GLI1 was not phosphorylated in the presence of the selective DYRK1A inhibitor harmine. The data described herein provide the first identification of a DYRK1A-mediated site of phosphorylation on GLI1 within its NLS and may serve as a valuable mechanism for further understanding Hh signaling modulation.

Keywords: DYRK1A; GLI1; Hedgehog; Mass spectrometry; Nuclear localization; Phosphorylation.

MeSH terms

  • Amino Acid Sequence
  • Binding Sites
  • Dyrk Kinases
  • HEK293 Cells
  • Hedgehog Proteins / chemistry
  • Hedgehog Proteins / metabolism
  • Humans
  • Nuclear Localization Signals / chemistry*
  • Nuclear Localization Signals / metabolism*
  • Phosphorylation
  • Protein Binding
  • Protein Serine-Threonine Kinases / chemistry*
  • Protein Serine-Threonine Kinases / metabolism*
  • Protein-Tyrosine Kinases / chemistry*
  • Protein-Tyrosine Kinases / metabolism*
  • Zinc Finger Protein GLI1 / chemistry*
  • Zinc Finger Protein GLI1 / metabolism*

Substances

  • Hedgehog Proteins
  • Nuclear Localization Signals
  • Zinc Finger Protein GLI1
  • Protein-Tyrosine Kinases
  • Protein Serine-Threonine Kinases