Kelch-Like Protein 2 Mediates Angiotensin II-With No Lysine 3 Signaling in the Regulation of Vascular Tonus

J Am Soc Nephrol. 2015 Sep;26(9):2129-38. doi: 10.1681/ASN.2014070639. Epub 2015 Jan 2.


Recently, the kelch-like protein 3 (KLHL3)-Cullin3 complex was identified as an E3 ubiquitin ligase for with no lysine (WNK) kinases, and the impaired ubiquitination of WNK4 causes pseudohypoaldosteronism type II (PHAII), a hereditary hypertensive disease. However, the involvement of WNK kinase regulation by ubiquitination in situations other than PHAII has not been identified. Previously, we identified the WNK3-STE20/SPS1-related proline/alanine-rich kinase-Na/K/Cl cotransporter isoform 1 phosphorylation cascade in vascular smooth muscle cells and found that it constitutes an important mechanism of vascular constriction by angiotensin II (AngII). In this study, we investigated the involvement of KLHL proteins in AngII-induced WNK3 activation of vascular smooth muscle cells. In the mouse aorta and mouse vascular smooth muscle (MOVAS) cells, KLHL3 was not expressed, but KLHL2, the closest homolog of KLHL3, was expressed. Salt depletion and acute infusion of AngII decreased KLHL2 and increased WNK3 levels in the mouse aorta. Notably, the AngII-induced changes in KLHL2 and WNK3 expression occurred within minutes in MOVAS cells. Results of KLHL2 overexpression and knockdown experiments in MOVAS cells confirmed that KLHL2 is the major regulator of WNK3 protein abundance. The AngII-induced decrease in KLHL2 was not caused by decreased transcription but increased autophagy-mediated degradation. Furthermore, knockdown of sequestosome 1/p62 prevented the decrease in KLHL2, suggesting that the mechanism of KLHL2 autophagy could be selective autophagy mediated by sequestosome 1/p62. Thus, we identified a novel component of signal transduction in AngII-induced vascular contraction that could be a promising drug target.

Keywords: angiotensin; hypertension; vascular.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adaptor Proteins, Signal Transducing / genetics
  • Angiotensin II / pharmacokinetics*
  • Angiotensin II / pharmacology
  • Animals
  • Aorta
  • Autophagy / drug effects
  • Cells, Cultured
  • Gene Knockdown Techniques
  • Heat-Shock Proteins / genetics
  • Mice
  • Microfilament Proteins / drug effects
  • Microfilament Proteins / genetics
  • Microfilament Proteins / metabolism*
  • Muscle Tonus / physiology*
  • Muscle, Smooth, Vascular / metabolism
  • Myocytes, Smooth Muscle / metabolism
  • Nerve Tissue Proteins / drug effects
  • Nerve Tissue Proteins / genetics
  • Nerve Tissue Proteins / metabolism*
  • Protein Serine-Threonine Kinases / drug effects
  • Protein Serine-Threonine Kinases / metabolism*
  • Sequestosome-1 Protein
  • Signal Transduction / drug effects*
  • Sodium, Dietary / pharmacology
  • Solute Carrier Family 12, Member 2 / metabolism
  • Vasoconstriction


  • Adaptor Proteins, Signal Transducing
  • Heat-Shock Proteins
  • KLHL3 protein, mouse
  • Klhl2 protein, mouse
  • Microfilament Proteins
  • Nerve Tissue Proteins
  • Sequestosome-1 Protein
  • Slc12a2 protein, mouse
  • Sodium, Dietary
  • Solute Carrier Family 12, Member 2
  • Sqstm1 protein, mouse
  • Angiotensin II
  • Stk39 protein, mouse
  • Protein Serine-Threonine Kinases
  • Wnk3 protein, mouse