PMID- 10861839
OWN - NLM
STAT- MEDLINE
DCOM- 20000824
LR  - 20211203
IS  - 0730-2312 (Print)
IS  - 0730-2312 (Linking)
VI  - 78
IP  - 3
DP  - 2000 Jun 6
TI  - Thapsigargin-induced grp78 expression is mediated by the increase of cytosolic 
      free calcium in 9L rat brain tumor cells.
PG  - 404-16
AB  - Exposure of 9L rat brain tumor cells to 300 nM thapsigargin (TG), a 
      sarcoendoplasmic Ca(2+)-ATPases inhibitor, leads to an immediate suppression of 
      general protein synthesis followed by an enhanced synthesis of the 78-kDa 
      glucose-regulated protein, GRP78. Synthesis of GRP78 increases significantly and 
      continues to rise after 4 h of treatment, and this process coincides with the 
      accumulation of grp78 mRNA. TG-induced grp78 expression can be suppressed by the 
      cytosolic free calcium ([Ca(2+)](c)) chelator dibromo-1, 
      2-bis(aminophenoxy)ethane N,N,N',N'-tetraacetic acid (BAPTA) in a 
      concentration-dependent manner. Induction of grp78 is completely abolished in the 
      presence of 20 microM BAPTA under which the TG-induced increase of [Ca(2+)](c) is 
      also completely prevented. By adding ethyleneglycol 
      bis(beta-aminoethyl)ether-N,N,N',N' tetraacetic acid in the foregoing 
      experiments, in a condition such that endoplasmic reticulum calcium 
      ([Ca(2+)](ER)) is depleted and calcium influx from outside is prevented, 
      TG-induced grp78 expression is also abolished. These data lead us to conclude 
      that increase in [Ca(2+)](c), together with the depletion of [Ca(2+)](ER), are 
      the major causes of TG-induced grp78 expression in 9L rat brain tumor cells. By 
      using electrophoretic mobility shift assays (EMSA), we found that the nuclear 
      extracts prepared from TG-treated cells exhibit an increase in binding activity 
      toward the extended grp78 promoter as well as the individual cis-acting 
      regulatory elements, CRE and CORE. Moreover, this increase in binding activity is 
      also reduced by BAPTA. By competitory assays using the cis-acting regulatory 
      elements as the competitors as well as the EMSA probes, we further show that all 
      of the tested cis elements-CRE, CORE, and C1-are involved in the basal as well as 
      in the TG-induced expression of grp78 and that the protein factor(s) that binds 
      to the C1 region plays an important role in the formation and maintenance of the 
      transcription complex.
CI  - Copyright 2000 Wiley-Liss, Inc.
FAU - Chen, L Y
AU  - Chen LY
AD  - Department of Life Science, National Tsing Hua University, Hsinchu, Taiwan, 
      Republic of China.
FAU - Chiang, A S
AU  - Chiang AS
FAU - Hung, J J
AU  - Hung JJ
FAU - Hung, H I
AU  - Hung HI
FAU - Lai, Y K
AU  - Lai YK
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - United States
TA  - J Cell Biochem
JT  - Journal of cellular biochemistry
JID - 8205768
RN  - 0 (Carrier Proteins)
RN  - 0 (Endoplasmic Reticulum Chaperone BiP)
RN  - 0 (Enzyme Inhibitors)
RN  - 0 (Heat-Shock Proteins)
RN  - 0 (Molecular Chaperones)
RN  - 0 (RNA, Messenger)
RN  - 526U7A2651 (Egtazic Acid)
RN  - 67526-95-8 (Thapsigargin)
RN  - K22DDW77C0 (1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid)
RN  - SY7Q814VUP (Calcium)
SB  - IM
MH  - Animals
MH  - Base Sequence
MH  - Blotting, Northern
MH  - Brain Neoplasms/drug therapy/*metabolism/pathology
MH  - Calcium/*metabolism
MH  - Carrier Proteins/*biosynthesis/genetics
MH  - Egtazic Acid/*analogs & derivatives/metabolism/pharmacology
MH  - Electrophoresis, Agar Gel
MH  - Endoplasmic Reticulum Chaperone BiP
MH  - Enzyme Inhibitors/*pharmacology
MH  - Gliosarcoma/drug therapy/*metabolism/pathology
MH  - *Heat-Shock Proteins
MH  - Molecular Chaperones/*biosynthesis/genetics
MH  - Molecular Sequence Data
MH  - RNA, Messenger/*biosynthesis
MH  - Rats
MH  - Regulatory Sequences, Nucleic Acid
MH  - Signal Transduction
MH  - Thapsigargin/*pharmacology
MH  - Tumor Cells, Cultured/metabolism
EDAT- 2000/06/22 10:00
MHDA- 2000/08/29 11:01
CRDT- 2000/06/22 10:00
PHST- 2000/06/22 10:00 [pubmed]
PHST- 2000/08/29 11:01 [medline]
PHST- 2000/06/22 10:00 [entrez]
AID - 10.1002/1097-4644(20000901)78:3<404::AID-JCB6>3.0.CO;2-8 [pii]
AID - 10.1002/1097-4644(20000901)78:3<404::aid-jcb6>3.0.co;2-8 [doi]
PST - ppublish
SO  - J Cell Biochem. 2000 Jun 6;78(3):404-16. doi: 
      10.1002/1097-4644(20000901)78:3<404::aid-jcb6>3.0.co;2-8.