PMID- 7744845
OWN - NLM
STAT- MEDLINE
DCOM- 19950612
LR  - 20210210
IS  - 0021-9258 (Print)
IS  - 0021-9258 (Linking)
VI  - 270
IP  - 20
DP  - 1995 May 19
TI  - Thapsigargin-resistant intracellular calcium pumps. Role in calcium pool function 
      and growth of thapsigargin-resistant cells.
PG  - 11955-61
AB  - Exposure of cells to the intracellular Ca2+ pump blocker, thapsigargin (TG), 
      results in emptying of Ca2+ pools and termination of cell proliferation (Short, 
      A. D., Bian, J., Ghosh, T. K., Waldron, R. T., Rybak, S. L., and Gill, D. L. 
      (1993) Proc. Natl. Acad. Sci. U.S.A. 90, 4986-4990). DC-3F Chinese hamster lung 
      cells were made resistant to TG by long-term stepwise exposure to increasing TG 
      concentrations in culture (Gutheil, J. C., Hart, S. R., Belani, C. P., Melera, P. 
      W., and Hussain, A. (1994) J. Biol. Chem. 269, 7976-7981). Since these cells 
      (DC-3F/TG2) grow in the presence of TG, it was important to ascertain what Ca2+ 
      pool function they retain. TG-resistant DC-3F/TG2 cells cultured with 2 microM TG 
      had a doubling time (24 h) not significantly different from the parent DC-3F 
      cells without TG. Analysis of TG-induced inhibition of 45Ca2+ uptake into 
      permeabilized parent DC-3F cells revealed two distinct Ca2+ pump activities with 
      20,000-fold different sensitivities to TG; the IC50 values for TG were 200 pM and 
      4 microM, representing 80% and 20% of total pumping activity, respectively. Total 
      pump activity in parent DC-3F and resistant DC-3F/TG2 cells was similar (0.23 +/- 
      0.10 and 0.18 +/- 0.08 nmol of Ca2+/10(6) cells, respectively). In DC-3F/TG2 
      cells, up to 100 nM TG had no effect on Ca2+ pumping; however, almost all pumping 
      was blocked at higher TG concentrations with an IC50 of 5 microM. In both cell 
      types, each Ca2+ pump activity (regardless of TG sensitivity) had high Ca2+ 
      affinity (Km values congruent to 0.1 microM) and similar ATP dependence and 
      vanadate sensitivity. In DC-3F cells, the TG-sensitive Ca2+ pool was releasable 
      with inositol 1,4,5-trisphosphate (InsP3) or GTP and was oxalate-permeable; the 
      TG-insensitive pool in these cells was not InsP3-releasable. GTP-induced Ca2+ 
      uptake in the presence of oxalate indicated Ca2+ transfer between distinct pools 
      in the DC-3F cells. In resistant DC-3F/TG2 cells, almost 50% of total 
      TG-insensitive Ca2+ accumulation was releasable with InsP3; unlike the parent 
      cells, this pool was not oxalate-permeable, and GTP induced no Ca2+ transfer 
      between pools in the presence of oxalate. Thus, whereas InsP3 releases Ca2+ only 
      from the high TG sensitivity Ca2+ pumping pool in parent DC-3F cells, in 
      resistant DC-3F/TG2 cells the TG-resistant Ca2+ pumping pool now contains 
      functional InsP3 receptors.(ABSTRACT TRUNCATED AT 400 WORDS)
FAU - Waldron, R T
AU  - Waldron RT
AD  - Department of Biological Chemistry, University of Maryland School of Medicine, 
      Baltimore 21201, USA.
FAU - Short, A D
AU  - Short AD
FAU - Gill, D L
AU  - Gill DL
LA  - eng
GR  - NS19304/NS/NINDS NIH HHS/United States
PT  - Comparative Study
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PT  - Research Support, U.S. Gov't, Non-P.H.S.
PT  - Research Support, U.S. Gov't, P.H.S.
PL  - United States
TA  - J Biol Chem
JT  - The Journal of biological chemistry
JID - 2985121R
RN  - 0 (Oxalates)
RN  - 0 (Terpenes)
RN  - 3WHH0066W5 (Vanadates)
RN  - 67526-95-8 (Thapsigargin)
RN  - 85166-31-0 (Inositol 1,4,5-Trisphosphate)
RN  - 86-01-1 (Guanosine Triphosphate)
RN  - EC 7.2.2.10 (Calcium-Transporting ATPases)
RN  - SY7Q814VUP (Calcium)
SB  - IM
EIN - J Biol Chem 1995 Aug 4;270(31):18710
MH  - Animals
MH  - Calcium/*metabolism
MH  - Calcium-Transporting ATPases/*antagonists & inhibitors
MH  - Cell Compartmentation
MH  - Cell Division/drug effects
MH  - Cell Line
MH  - Cell Survival
MH  - Cricetinae
MH  - Cricetulus
MH  - Drug Resistance
MH  - Fibroblasts/drug effects/metabolism
MH  - Guanosine Triphosphate/pharmacology
MH  - Inositol 1,4,5-Trisphosphate/pharmacology
MH  - Lung
MH  - Oxalates/metabolism
MH  - Signal Transduction
MH  - Terpenes/*pharmacology
MH  - Thapsigargin
MH  - Vanadates/pharmacology
EDAT- 1995/05/19 00:00
MHDA- 1995/05/19 00:01
CRDT- 1995/05/19 00:00
PHST- 1995/05/19 00:00 [pubmed]
PHST- 1995/05/19 00:01 [medline]
PHST- 1995/05/19 00:00 [entrez]
AID - S0021-9258(17)47930-0 [pii]
AID - 10.1074/jbc.270.20.11955 [doi]
PST - ppublish
SO  - J Biol Chem. 1995 May 19;270(20):11955-61. doi: 10.1074/jbc.270.20.11955.