Activation of ryanodine receptors induces calcium influx in a neuroblastoma cell line lacking calcium influx factor activity.
We have further characterized the Ca2+ signalling properties of the NG115-401L (or 401L) neuroblastoma cell line, which has served as an important cell line for investigating SOC (store-operated channel) influx pathways. These cells possess an unusual Ca2+ signalling phenotype characterized by the absence of Ca2+ influx when Ca2+ stores are depleted by inhibitors of SERCA (sarcoplasmic/endoplasmic reticulum Ca2+-ATPase). Previous studies found that Ca2+-store depletion does not produce a CIF (Ca2+ influx factor) activity in 401L cells. These observations have prompted the question whether 401L cells possess the signalling machinery that permits non-voltage-gated Ca2+ influx to occur. We tested the hypothesis that ryanodine-sensitive Ca2+ pools and activation of RyRs (ryanodine receptors) constitute a signalling pathway capable of inducing Ca2+ influx in 401L cells. We found that 401L cells express mRNA for RyR1 and RyR2 and that RyR activators induced Ca2+ release. Activation of RyRs robustly couples with Ca2+ influx responses in 401L cells, in sharp contrast with absence of Ca2+ influx when cells are treated with SERCA inhibitors. Thus it is clear that 401L cells, despite lacking depletion-induced Ca2+ influx pathways, express the functional components of a Ca2+ influx pathway under the control of RyR function. These findings further support the importance of the 401L cell line as an important cell phenotype for deciphering Ca2+ influx regulation.
Department of Physiology and Pharmacology, Thomas J. Long School of Pharmacy and Health Sciences, University of the Pacific, Stockton, CA 95211, USA.
Diptiman D
DD
Bose
Roshanak
R
Rahimian
David W
DW
Thomas
D002118:Calcium / Q000378:metabolism*; D015220:Calcium Channels / Q000378:metabolism; D020013:Calcium Signaling / Q000502:physiology; D000252:Calcium-Transporting ATPases / Q000037:antagonists & inhibitors; D002460:Cell Line; D053496:Inositol 1,4,5-Trisphosphate Receptors; D009447:Neuroblastoma / Q000378:metabolism*; D018160:Receptors, Cytoplasmic and Nuclear / Q000378:metabolism; D019837:Ryanodine Receptor Calcium Release Channel / Q000378:metabolism*; D053498:Sarcoplasmic Reticulum Calcium-Transporting ATPases
D015220:Calcium Channels; D053496:Inositol 1,4,5-Trisphosphate Receptors; D018160:Receptors, Cytoplasmic and Nuclear; D019837:Ryanodine Receptor Calcium Release Channel; D053498:Sarcoplasmic Reticulum Calcium-Transporting ATPases; D000252:Calcium-Transporting ATPases; D002118:Calcium