Author: Van Baelen, K.; Vanoevelen, J.; Callewaert, G.; Parys, J.B.; De Smedt, H.; Raeymaekers, L.; Rizzuto, R.; Missiaen, L.; Wuytack, F.
Description: The secretory-pathway Ca(2+)-ATPase SPCA1 is a thapsigargin-insensitive intracellular Ca(2+) pump found mostly in the Golgi compartment. We have explored the contribution of this Ca(2+) pump to cytosolic Ca(2+) signaling in HeLa cells by using RNA-mediated interference to disrupt its expression. Removal of SPCA1 was confirmed by immunofluorescence with specific anti-SPCA1 antibodies. Measurements of the free Ca(2+) concentration in the lumen of the Golgi apparatus by specifically targeting the Ca(2+)-sensitive luminescent protein aequorin to this organelle revealed that endogenous SPCA1 was responsible for Ca(2+) uptake in a subfraction of the Golgi apparatus. HeLa cells lacking SPCA1 could still set up baseline Ca(2+) spiking when stimulated with histamine, indicating that the SPCA1-containing Ca(2+) store was not absolutely needed to set up these oscillations. However, baseline Ca(2+) oscillations occurred less frequently than in control cells, pointing to a contribution of SPCA1 in the shaping of the cytosolic Ca(2+) signal in HeLa cells.
Subject headings: Calcium/metabolism; Calcium-Transporting ATPases/chemistry/metabolism/physiology; Cell Membrane/metabolism; Endoplasmic Reticulum/metabolism; Enzyme Inhibitors/pharmacology; Genetic Vectors; Golgi Apparatus/metabolism; HeLa Cells; Humans; Immunoblotting; Immunohistochemistry; Kinetics; Microscopy, Fluorescence; RNA Interference; Recombinant Proteins/metabolism; Thapsigargin/pharmacology; Transfection
Publication year: 2003
Journal or book title: Biochemical and Biophysical Research Communications
Find the full text : https://www.sciencedirect.com/science/article/pii/S0006291X0300977X
Find more like this one (cited by): https://scholar.google.com/scholar?cites=3688929905766328867&as_sdt=1000005&sciodt=0,16&hl=en
Type: Journal Article
Serial number: 120