ALPK1 phosphorylates myosin IIA modulating TNF-α trafficking in gout flares

Sci Rep. 2016 May 12:6:25740. doi: 10.1038/srep25740.

Abstract

Gout is characterized by the monosodium urate monohydrate (MSU)-induced arthritis. Alpha kinase-1 (ALPK1) has shown to be associated with MSU-induced inflammation and gout. Here, we used bioinformatics, proteomics, cell models, and twenty in vitro human assays to clarify some of its role in the inflammatory response to MSU. We found myosin IIA to be a frequent interacting protein partner of ALPK1, binding to its N-terminal and forming a protein complex with calmodulin and F-actin, and that MSU-induced ALPK1 phosphorylated the myosin IIA. A knockdown of endogenous ALPK1 or myosin IIA significantly reduced the MSU-induced secretion of tumour necrosis factor (TNF)-α. Furthermore, all gouty patients expressed higher basal protein levels of ALPK1, myosin IIA, and plasma TNF-α, however those medicated with colchicine has shown reduced myosin IIA and TNF-α but not ALPK1. The findings suggest ALPK1 is a kinase that participates in the regulation of Golgi-derived TNF-α trafficking through myosin IIA phosphorylation in the inflammation of gout. This novel pathway could be blocked at the level of myosin by colchicine in gout treatment.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Cell Line
  • Colchicine / pharmacology
  • Cytokines / metabolism
  • Down-Regulation / drug effects
  • Gene Knockdown Techniques
  • Genetic Vectors / metabolism
  • Gout / blood
  • Gout / metabolism*
  • HEK293 Cells
  • Humans
  • Models, Biological
  • Monocytes / drug effects
  • Monocytes / metabolism
  • Nonmuscle Myosin Type IIA / metabolism*
  • Phosphorylation / drug effects
  • Protein Binding / drug effects
  • Protein Domains
  • Protein Kinases / chemistry
  • Protein Kinases / metabolism*
  • Protein Structure, Secondary
  • Tumor Necrosis Factor-alpha / blood
  • Tumor Necrosis Factor-alpha / metabolism*
  • Uric Acid / pharmacology

Substances

  • Cytokines
  • Tumor Necrosis Factor-alpha
  • Uric Acid
  • Protein Kinases
  • Nonmuscle Myosin Type IIA
  • Colchicine