Control of nuclear-cytoplasmic shuttling of Ankrd54 by PKCδ

Amy L Samuels1, Alison Louw1, Reza Zareie2

  • 1Cell Signalling Group, Harry Perkins Institute of Medical Research and Centre for Medical Research, the University of Western Australia, Nedlands, WA 6009, Australia.

Abstract

Insights

Phosphorylation by PKCδ regulates Ankrd54

Area of Science:

  • Cell Biology
  • Molecular Biology
  • Biochemistry

Background:

  • Ankrd54 is a protein involved in nuclear-cytoplasmic transport.
  • Phosphorylation is a key post-translational modification regulating protein function and localization.

Purpose of the Study:

  • To investigate the role of phosphorylation in Ankrd54's subcellular localization.
  • To identify kinases that regulate Ankrd54 phosphorylation and localization.

Main Methods:

  • HEK293T cells were treated with kinase activators (PMA, calyculin A, staurosporin).
  • Ankrd54 was expressed with or without Lyn tyrosine kinase variants.
  • Subcellular localization was assessed via immunofluorescence and subcellular fractionation.
  • Phosphorylation was analyzed using Phos-tag gel assays and MRM proteomics.

Main Results:

  • Phorbol 12-myristate 13-acetate (PMA) treatment induced Ankrd54 nuclear export and increased its phosphorylation.
  • PKCδ activation specifically promoted Ankrd54 phosphorylation and cytoplasmic localization.
  • Mutations of serine residues (Ser14, 17, 18, 19) reduced PMA-induced effects.
  • Phosphorylation at Ser18 was confirmed by MRM analysis.
  • PMA stimulation enhanced Ankrd54 interaction and co-localization with Lyn tyrosine kinase.

Conclusions:

  • PKCδ-mediated phosphorylation is a key regulator of Ankrd54's nuclear-cytoplasmic shuttling.
  • Phosphorylation influences Ankrd54's interaction with Lyn tyrosine kinase.

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