Inhibition of thapsigargin-induced calcium entry by microinjected guanine nucleotide analogues. Evidence for the involvement of a small G-protein in capacitative calcium entry.
Year: 1993
Type: article
Abstract: Injection of mouse lacrimal acinar cells with the non-hydrolyzable analogue of GTP, GTP gamma S (guanosine 5'-3-O-(thio)triphosphate), caused a rapid release of intracellular calcium but failed to activate calcium entry. Injection of GTP gamma S together with the inositol 1,4,5-trisphosphate receptor inhibitor, heparin, did not induce calcium release but blocked the activation of capacitative calcium entry by thapsigargin. Injection of GDP beta S (guanosine 5'-O-(thio)diphosphate) produced similar effects. The inhibitor effects of GDP beta S were prevented if an equal concentration of GTP was included in the injection pipette. These findings suggest that one of the steps linking the depletion of intracellular calcium pools to calcium entry across the plasma membrane requires the hydrolysis of GTP and may involve a small G-protein.
Source: Journal of Biological Chemistry
Authors: G.S. Bird, J.W. Putney
Institution: National Institute of Environmental Health Sciences
Language: English
Topic: Ion Channels and Receptors
Subfield: Sensory Systems
Field: Neuroscience
Domain: Life Sciences
Open Access status: hybrid
Estimated APC paid: $3,430
OpenAlex ID: W1545068312