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Osmosensing by WNK Kinases.
Akella, Radha; Humphreys, John M; Sekulski, Kamil; He, Haixia; Durbacz, Mateusz; Chakravarthy, Srinivas; Liwocha, Joanna; Mohammed, Zuhair J; Brautigam, Chad A; Goldsmith, Elizabeth J.
Afiliação
  • Akella R; Department of Biophysics, The University of Texas Southwestern Medical Center, Dallas, TX 75390.
  • Humphreys JM; Department of Biophysics, The University of Texas Southwestern Medical Center, Dallas, TX 75390.
  • Sekulski K; Department of Biophysics, The University of Texas Southwestern Medical Center, Dallas, TX 75390.
  • He H; Department of Biophysics, The University of Texas Southwestern Medical Center, Dallas, TX 75390.
  • Durbacz M; Department of Biophysics, The University of Texas Southwestern Medical Center, Dallas, TX 75390.
  • Chakravarthy S; Department of Biology, Chemistry, & Physical Sciences, APS/Illinois Institute of Technology, Argonne, IL 60439.
  • Liwocha J; Department of Molecular Biology, The University of Texas Southwestern Medical Center, Dallas, TX 75390.
  • Mohammed ZJ; Baylor College of Medicine, Houston, TX 77030.
  • Brautigam CA; Department of Biophysics, The University of Texas Southwestern Medical Center, Dallas, TX 75390.
  • Goldsmith EJ; Department of Microbiology, The University of Texas Southwestern Medical Center, Dallas, TX 75390.
Mol Biol Cell ; 32(18): 1614-1623, 2021 08 19.
Article em En | MEDLINE | ID: mdl-33689398
With No Lysine (K) WNK kinases regulate electro-neutral cotransporters that are controlled by osmotic stress and chloride. We showed previously that autophosphorylation of WNK1 is inhibited by chloride, raising the possibility that WNKs are activated by osmotic stress. Here we demonstrate that unphosphorylated WNK isoforms 3 and 1 autophosphorylate in response to osmotic pressure in vitro, applied with the crowding agent polyethylene glycol (PEG)400 or osmolyte ethylene glycol (EG), and that this activation is opposed by chloride. Small angle x-ray scattering of WNK3 in the presence and absence of PEG400, static light scattering in EG, and crystallography of WNK1 were used to understand the mechanism. Osmosensing in WNK3 and WNK1 appears to occur through a conformational equilibrium between an inactive, unphosphorylated, chloride-binding dimer and an autophosphorylation-competent monomer. An improved structure of the inactive kinase domain of WNK1, and a comparison with the structure of a monophosphorylated form of WNK1, suggests that large cavities, greater hydration, and specific bound water may participate in the osmosensing mechanism. Our prior work showed that osmolytes have effects on the structure of phosphorylated WNK1, suggestive of multiple stages of osmotic regulation in WNKs.
Assuntos

Texto completo: 1 Base de dados: MEDLINE Assunto principal: Proteínas Quinases / Proteína Quinase 1 Deficiente de Lisina WNK Idioma: En Ano de publicação: 2021 Tipo de documento: Article

Texto completo: 1 Base de dados: MEDLINE Assunto principal: Proteínas Quinases / Proteína Quinase 1 Deficiente de Lisina WNK Idioma: En Ano de publicação: 2021 Tipo de documento: Article