KLHL2 interacts with and ubiquitinates WNK kinases

Biochem Biophys Res Commun. 2013 Aug 2;437(3):457-62. doi: 10.1016/j.bbrc.2013.06.104. Epub 2013 Jul 6.

Abstract

Mutations in the WNK1 and WNK4 genes result in an inherited hypertensive disease, pseudohypoaldosteronism type II (PHAII). Recently, the KLHL3 and Cullin3 genes were also identified as responsible genes for PHAII. Although we have reported that WNK4 is a substrate for the KLHL3-Cullin3 E3 ligase complex, it is not clear whether all of the WNK isoforms are regulated only by KLHL3. To explore the interaction of WNKs and other Kelch-like proteins, we focused on KLHL2 (Mayven), a human homolog of Drosophila Kelch that shares the highest similarity with KLHL3. We found that KLHL2, as well as KLHL3, was co-immunoprecipitated with all four WNK isoforms. The direct interaction of KLHL2 with WNKs was confirmed on fluorescence correlation spectroscopy. Co-expression of KLHL2 and Cullin3 decreased the abundance of WNK1, WNK3 and WNK4 within HEK293T cells, and a significant increase of WNK4 ubiquitination by KLHL2 and Cullin3 was observed both in HEK293T cells and in an in vitro ubiquitination assay. These results suggest that KLHL2-Cullin3 also functions as an E3-ligase for WNK isoforms within the body.

Keywords: Cullin-3; Kelch-like protein 2; Ubiquitination; WNK kinase.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adaptor Proteins, Signal Transducing
  • Amino Acid Sequence
  • Carrier Proteins / metabolism
  • HEK293 Cells
  • Humans
  • Hydrogen-Ion Concentration
  • Intracellular Signaling Peptides and Proteins / antagonists & inhibitors
  • Intracellular Signaling Peptides and Proteins / metabolism
  • Microfilament Proteins / metabolism*
  • Minor Histocompatibility Antigens
  • Molecular Sequence Data
  • Nerve Tissue Proteins / metabolism*
  • Protein Binding
  • Protein Structure, Tertiary
  • Protein-Serine-Threonine Kinases / antagonists & inhibitors
  • Protein-Serine-Threonine Kinases / metabolism
  • Ubiquitin-Protein Ligases / metabolism
  • WNK Lysine-Deficient Protein Kinase 1

Substances

  • Adaptor Proteins, Signal Transducing
  • Carrier Proteins
  • Intracellular Signaling Peptides and Proteins
  • KLHL2 protein, human
  • KLHL3 protein, human
  • Microfilament Proteins
  • Minor Histocompatibility Antigens
  • Nerve Tissue Proteins
  • Ubiquitin-Protein Ligases
  • Protein-Serine-Threonine Kinases
  • WNK Lysine-Deficient Protein Kinase 1
  • WNK1 protein, human
  • WNK3 protein, human
  • WNK4 protein, human