RRC ID |
74606
|
Author |
Ohsaka Y, Ohgiya S, Hoshino T, Ishizaki K.
|
Title |
Mitochondrial genome-encoded ATPase subunit 6+8 mRNA increases in human hepatoblastoma cells in response to nonfatal cold stress.
|
Journal |
Cryobiology
|
Abstract |
Cellular responses to cold stress have not been well clarified, compared with heat shock responses, especially in mammalian cells. We investigated cold-stress responses in human hepatoblastoma cells (HepG2) exposed to a nonfatal temperature of 17 degrees C. Under the condition, RNA and protein syntheses in the cells were highly, but incompletely, depressed and cell growth was impaired. A cDNA subtraction method was used to isolate mRNAs for which the levels were increased in cold-stressed cells compared with cells cultured at 37 degrees C. A transcript isolated by the screening was identified as ATPase subunit 6+8 mRNA that encodes components of a mitochondrial ATPase complex and that is transcribed from a mitochondrial genome. The copy number of the mitochondrial genome in cells was not changed by cold stress. Thus, HepG2 cells were treated with various concentrations of actinomycin D and chloramphenicol to assess the effects of transcriptional and translational reduction on the increased level of the ATPase subunit 6+8 mRNA. The mRNA level was increased in cells treated with low concentrations of the RNA or protein synthesis inhibitors. These results indicate that the increase in ATPase subunit 6+8 mRNA stimulated by cold stress could be mediated by a partial decline of transcription and/or translation in the cells. In addition, the degradation of ATPase subunit 6+8 mRNA was suppressed in cold-stressed cells compared with that in 37 degrees C-cultured cells. This result implies that posttranscriptional regulation is also involved in the cold-stimulated increase in ATPase subunit 6+8 mRNA in HepG2 cells.
|
Volume |
40(2)
|
Pages |
92-101
|
Published |
2000-3-1
|
DOI |
10.1006/cryo.2000.2237
|
PII |
S0011-2240(00)92237-5
|
PMID |
10788308
|
MeSH |
Apoptosis
Cold Temperature*
DNA Replication
DNA, Complementary / genetics
DNA, Mitochondrial / genetics
Enzyme Induction
Gene Expression Regulation, Neoplastic*
Hepatoblastoma / enzymology
Hepatoblastoma / pathology*
Humans
Liver Neoplasms / enzymology
Liver Neoplasms / pathology*
Proton-Translocating ATPases / genetics*
RNA, Messenger / biosynthesis*
RNA, Neoplasm / biosynthesis*
Stress, Physiological / genetics
Stress, Physiological / metabolism
Subtraction Technique
Tumor Cells, Cultured / enzymology
|
IF |
2.287
|
Resource |
Human and Animal Cells |
Hep G2(RCB0459) |