title: Nitric oxide enhances extracellular ATP induced Ca²⁺ oscillation in HeLa cells.
abstract: Calcium (Ca(2+)) oscillations play a central role in varieties of cellular processes including fertilization and immune response, but controversy over the regulation mechanisms still exists. It has been known that nitric oxide (NO) dependently regulates Ca(2+) signaling in most physiopathological processes. Previous study indicated that eNOS translocation during some pathological process influences intracellular Ca(2+) homeostasis. In this study, we investigated the role and mechanism of NO on Ca(2+) release by overexpressing eNOS in cytoplasm (Cyto-eNOS) and endoplasmic reticulum (ER-eNOS) of HeLa cells. We found that the properties of Ca(2+) release were altered by the overexpression of eNOS. The amplitude and frequency of extracellular ATP (eATP)-induced Ca(2+) oscillation were enhanced in both Cyto-eNOS and ER-eNOS cells, respectively. Especially, the enhancement of the amplitude and frequency of the Ca(2+) oscillation was much more significant in the ER-eNOS cells than that of Cyto-eNOS cells. Further study indicated that this effect was abrogated by NO inhibitor, L-NAME, suggesting it was not an artificial result induced by ER stress. Furthermore, an up-regulated phosphorylation of phospholamban (PLB) was observed and the sarco-endoplasmic reticulum Ca(2+)-ATPase (SERCA) function was activated followed by the significant increase in the ER Ca(2+) load. Taken together, we revealed a novel regulatory mechanism of Ca(2+) oscillation.
authors.affiliation: National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China; University of the Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Yinglong
authors.initials: Y
authors.lastname: Tang
authors.affiliation: General Hospital of Air Force, Stomatology, Beijing, China.
authors.forename: Yin
authors.initials: Y
authors.lastname: Yin
authors.affiliation: National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China.
authors.forename: Lin
authors.initials: L
authors.lastname: Miao
authors.affiliation: Department of Physiology, Wayne State University School of Medicine, Detroit, MI 48201, United States.
authors.forename: Bin
authors.initials: B
authors.lastname: Wei
authors.affiliation: National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China.
authors.forename: Kui
authors.initials: K
authors.lastname: Zhai
authors.affiliation: National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China. Electronic address: gj28@ibp.ac.cn.
authors.forename: Guangju
authors.initials: G
authors.lastname: Ji
mesh_terms: D000255:Adenosine Triphosphate / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology*; D020013:Calcium Signaling / Q000187:drug effects*; D002135:Calcium-Binding Proteins / Q000235:genetics / Q000378:metabolism; D003593:Cytoplasm / Q000235:genetics / Q000378:metabolism*; D004721:Endoplasmic Reticulum / Q000235:genetics / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006367:HeLa Cells; D006801:Humans; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D009569:Nitric Oxide / Q000235:genetics / Q000378:metabolism*; D052250:Nitric Oxide Synthase Type III / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D053498:Sarcoplasmic Reticulum Calcium-Transporting ATPases / Q000235:genetics / Q000378:metabolism; D000099211:Phospholamban
chemical_list: D000255:Adenosine Triphosphate; D002135:Calcium-Binding Proteins; D004791:Enzyme Inhibitors; D019331:NG-Nitroarginine Methyl Ester; D009569:Nitric Oxide; D052250:Nitric Oxide Synthase Type III; D053498:Sarcoplasmic Reticulum Calcium-Transporting ATPases; D000099211:Phospholamban; C496314:NOS3 protein, human
keywords: Calcium oscillation; Nitric oxide; Phospholamban; eNOS