Thapsigargin, a tumor promoter, discharges intracellular Ca2+ stores by specific inhibition of the endoplasmic reticulum Ca2(+)-ATPase
Research output: Contribution to journal › Journal article › Research › peer-review
Standard
Thapsigargin, a tumor promoter, discharges intracellular Ca2+ stores by specific inhibition of the endoplasmic reticulum Ca2(+)-ATPase. / Thastrup, Ole; Cullen, P J; Drøbak, B K; Hanley, M R; Dawson, A P.
In: Proceedings of the National Academy of Sciences of the United States of America, Vol. 87, No. 7, 1990, p. 2466-70.Research output: Contribution to journal › Journal article › Research › peer-review
Harvard
APA
Vancouver
Author
Bibtex
}
RIS
TY - JOUR
T1 - Thapsigargin, a tumor promoter, discharges intracellular Ca2+ stores by specific inhibition of the endoplasmic reticulum Ca2(+)-ATPase
AU - Thastrup, Ole
AU - Cullen, P J
AU - Drøbak, B K
AU - Hanley, M R
AU - Dawson, A P
PY - 1990
Y1 - 1990
N2 - Thapsigargin, a tumor-promoting sesquiterpene lactone, discharges intracellular Ca2+ in rat hepatocytes, as it does in many vertebrate cell types. It appears to act intracellularly, as incubation of isolated rat liver microsomes with thapsigargin induces a rapid, dose-dependent release of stored Ca2+. The thapsigargin-releasable pool of microsomal Ca2+ includes the pools sensitive to inositol 1,4,5-trisphosphate and GTP. Thapsigargin pretreatment of microsomes blocks subsequent loading with 45Ca2+, suggesting that its target is the ATP-dependent Ca2+ pump of endoplasmic reticulum. This hypothesis is strongly supported by the demonstration that thapsigargin causes a rapid inhibition of the Ca2(+)-activated ATPase activity of rat liver microsomes, with an identical dose dependence to that seen in whole cell or isolated microsome Ca2+ discharge. The inhibition of the endoplasmic reticulum isoform of the Ca2(+)-ATPase is highly selective, as thapsigargin has little or no effect on the Ca2(+)-ATPases of hepatocyte or erythrocyte plasma membrane or of cardiac or skeletal muscle sarcoplasmic reticulum. These results suggest that thapsigargin increases the concentration of cytosolic free Ca2+ in sensitive cells by an acute and highly specific arrest of the endoplasmic reticulum Ca2+ pump, followed by a rapid Ca2+ leak from at least two pharmacologically distinct Ca2+ stores. The implications of this mechanism of action for the application of thapsigargin in the analysis of Ca2+ homeostasis and possible forms of Ca2+ control are discussed.
AB - Thapsigargin, a tumor-promoting sesquiterpene lactone, discharges intracellular Ca2+ in rat hepatocytes, as it does in many vertebrate cell types. It appears to act intracellularly, as incubation of isolated rat liver microsomes with thapsigargin induces a rapid, dose-dependent release of stored Ca2+. The thapsigargin-releasable pool of microsomal Ca2+ includes the pools sensitive to inositol 1,4,5-trisphosphate and GTP. Thapsigargin pretreatment of microsomes blocks subsequent loading with 45Ca2+, suggesting that its target is the ATP-dependent Ca2+ pump of endoplasmic reticulum. This hypothesis is strongly supported by the demonstration that thapsigargin causes a rapid inhibition of the Ca2(+)-activated ATPase activity of rat liver microsomes, with an identical dose dependence to that seen in whole cell or isolated microsome Ca2+ discharge. The inhibition of the endoplasmic reticulum isoform of the Ca2(+)-ATPase is highly selective, as thapsigargin has little or no effect on the Ca2(+)-ATPases of hepatocyte or erythrocyte plasma membrane or of cardiac or skeletal muscle sarcoplasmic reticulum. These results suggest that thapsigargin increases the concentration of cytosolic free Ca2+ in sensitive cells by an acute and highly specific arrest of the endoplasmic reticulum Ca2+ pump, followed by a rapid Ca2+ leak from at least two pharmacologically distinct Ca2+ stores. The implications of this mechanism of action for the application of thapsigargin in the analysis of Ca2+ homeostasis and possible forms of Ca2+ control are discussed.
KW - Animals
KW - Biological Transport
KW - Calcium
KW - Calcium-Transporting ATPases
KW - Carcinogens
KW - Cell Membrane
KW - Cells, Cultured
KW - Endoplasmic Reticulum
KW - Fluorescent Dyes
KW - Guanosine Triphosphate
KW - Humans
KW - Indoles
KW - Inositol 1,4,5-Trisphosphate
KW - Kinetics
KW - Liver
KW - Male
KW - Microsomes, Liver
KW - Plants, Medicinal
KW - Rats
KW - Terpenes
KW - Thapsigargin
M3 - Journal article
C2 - 2138778
VL - 87
SP - 2466
EP - 2470
JO - Proceedings of the National Academy of Sciences of the United States of America
JF - Proceedings of the National Academy of Sciences of the United States of America
SN - 0027-8424
IS - 7
ER -
ID: 43349844