Characterization of eNOS ser‐600 Phosphorylation: A Link to the Cell Cycle

Abstract

Nitric oxide (NO) is a gaseous, free‐radical signaling molecule produced by nitric oxide synthases (NOS). NO has a variety of cellular and physiological functions ranging from maintaining cardiovascular homeostasis to neurotransmission. In low concentrations NO is deemed physiologically crucial and in high concentrations NO is understood to be pathophysiological. The role of NO in the cell cycle is less understood, it is likely cell type specific and concentration dependent, in many cases low levels of NO promote proliferation and prevent apoptosis; at high levels NO has been shown to arrest cells and cause apoptosis. Endothelial nitric oxide synthase (eNOS) is one of three isoforms in the NOS family, it is the most regulated of the isoforms. Regulations include protein‐protein interactions and posttranslational modifications. The most commonly studied and well understood posttranslational modification of eNOS is phosphorylation. This work builds on our laboratories discovery of the ser‐600 phosphorylation site in the auto‐inhibitory loop of eNOS. Our work confirms this site is modulated in cells and links it to the cell cycle using immunofluorescence, flow cytometry, western blot analysis, in vitro kinase assays, and in vitro eNOS activity assays.Support or Funding InformationThis work was supported by NIH grant # R15 GM110634‐01A1 to Dr. Carol Chrestensen.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.