The Na+/H+ exchanger isoform-1 (NHE-1) is the key member of a family of exchangers that regulates intracellular pH and cell volume. Activation of NHE-1 by growth factors is rapid, correlates with increased NHE-1 phosphorylation and cell alkalinization, and plays a role in cell cycle progression. By two-dimensional tryptic peptide mapping of immunoprecipitated NHE-1, we identify serine 703 as the major serum-stimulated amino acid. Mutation of serine 703 to alanine had no effect on acid-stimulated Na+/H+ exchange but completely prevented the growth factor-mediated increase in NHE-1 affinity for H+. In addition, we show that p90 ribosomal S6 kinase (p90(RSK)) is a key NHE-1 kinase since p90(RSK) phosphorylates NHE-1 serine 703 stoichiometrically in vitro, and transfection with kinase-inactive p90(RSK) inhibits serum-induced phosphorylation of NHE-1 serine 703 in transfected 293 cells. These findings establish p90(RSK) as a serum-stimulated NHE-1 kinase and a mediator of increased Na+/H+ exchange in vivo.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1074/jbc.274.29.20206 | DOI Listing |
Immun Inflamm Dis
December 2024
Department of Neurology, Shanghai East Hospital, School of Medicine, Tongji University, Shanghai, China.
Sci Rep
November 2024
Department of Ophthalmology, Guro Hospital, Korea University College of Medicine, 80, Guro-dong, Guro-gu, Seoul, 152-703, South Korea.
The Coronavirus disease 2019 (COVID-19) pandemic has led to a global health crisis, including ocular symptoms, primarily targeting the Angiotensin-Converting Enzyme 2 (ACE2) receptor. PM2.5 air pollution may increase infection risk by altering ACE2 expression.
View Article and Find Full Text PDFBiochem Biophys Res Commun
April 2024
The School of Basic Medical Sciences, Fujian Medical University, Fuzhou, China. Electronic address:
Necroptosis is a form of regulated cell death that depends on the receptor-interacting serine-threonine kinase 3 (RIPK3) and mixed lineage kinase domain-like (MLKL). The molecular mechanisms underlying distinct instances of necroptosis have only recently begun to emerge. In the present study, we characterized RABGEF1 as a positive regulator of RIPK1/RIPK3 activation in vitro.
View Article and Find Full Text PDFCancer Res
March 2024
Department of Cancer Systems Imaging, The University of Texas MD Anderson Cancer Center, Houston, Texas.
Unlabelled: Lipid metabolism plays a central role in prostate cancer. To date, the major focus has centered on de novo lipogenesis and lipid uptake in prostate cancer, but inhibitors of these processes have not benefited patients. A better understanding of how cancer cells access lipids once they are created or taken up and stored could uncover more effective strategies to perturb lipid metabolism and treat patients.
View Article and Find Full Text PDFDiabetol Metab Syndr
October 2023
Department of Internal Medicine, Botucatu Medical School, Sao Paulo State University (UNESP), Botucatu, SP, Brazil.
Background: Sodium-glucose cotransporter (SGLT)2 inhibitors have displayed beneficial effects on the cardiovascular system in diabetes mellitus (DM) patients. As most clinical trials were performed in Type 2 DM, their effects in Type 1 DM have not been established.
Objective: To evaluate the influence of long-term treatment with SGLT2 inhibitor dapagliflozin on cardiac remodeling, myocardial function, energy metabolism, and metabolomics in rats with Type 1 DM.
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!