TY - JOUR
T1 - DNA damage response of cloned DNA β-polymerase promoter is blocked in mutant cell lines deficient in protein kinase A
AU - Englander, Ella W.
AU - Wilson, Samuel H.
PY - 1992/11/11
Y1 - 1992/11/11
N2 - DNA β3-polymerase (β-pol), one of the recognized DNA polymerizing enzymes in vertebrates, has a role in 'very short patch' gap-filling synthesis during nucleotide excision DNA repair. In human and mouse, the enzyme is encoded by a single-copy gene located on the short arm of chromosome 8 near the centromere. In a series of studies, we have found that the cloned human β-pol promoter is regulated by signals acting through the single ATF/CRE palindrome in the core promoter. These signals include transactivation by: adenovirus E1a/E1b proteins; activated p21ras; and in CHO cells, treatment with the DNA damaging agent MNNG. Hence, several types of stimulatory signals are mediated through the single ATF/CRE site, including DNA damage induction. To understand the mechanism of β-pol promoter activation by MNNG in CHO cells, we asked whether induction of the cAMP/protein kinase A pathway can increase transcription of the cloned promoter in this system. Agents that increase cellular cAMP levels (8-BrcAMP; forskolin and IBMx) activated the β-pol promoter fusion gene in transient expression experiments, and a mutation in the ATF/CRE palindrome blocked this response. Thus, the ATF/CRE site appears to be cAMP responsive in the CHO cell system. We found that the activation of the cloned β-pol promoter by MNNG does not occur with two mutant CHO cell lines that are deficient in protein kinase A activity. Further, simultaneous treatment of wild-type CHO cells, with MNNG and to elevate cAMP, failed to result in an additive effect for activation of the /-pol promoter. Thus, these effectors may act through a common pathway. These results suggest that the activation of the cloned β-pol promoter in CHO cells following MNNG treatment is mediated through the cAMP/protein kinase A signal transduction pathway.
AB - DNA β3-polymerase (β-pol), one of the recognized DNA polymerizing enzymes in vertebrates, has a role in 'very short patch' gap-filling synthesis during nucleotide excision DNA repair. In human and mouse, the enzyme is encoded by a single-copy gene located on the short arm of chromosome 8 near the centromere. In a series of studies, we have found that the cloned human β-pol promoter is regulated by signals acting through the single ATF/CRE palindrome in the core promoter. These signals include transactivation by: adenovirus E1a/E1b proteins; activated p21ras; and in CHO cells, treatment with the DNA damaging agent MNNG. Hence, several types of stimulatory signals are mediated through the single ATF/CRE site, including DNA damage induction. To understand the mechanism of β-pol promoter activation by MNNG in CHO cells, we asked whether induction of the cAMP/protein kinase A pathway can increase transcription of the cloned promoter in this system. Agents that increase cellular cAMP levels (8-BrcAMP; forskolin and IBMx) activated the β-pol promoter fusion gene in transient expression experiments, and a mutation in the ATF/CRE palindrome blocked this response. Thus, the ATF/CRE site appears to be cAMP responsive in the CHO cell system. We found that the activation of the cloned β-pol promoter by MNNG does not occur with two mutant CHO cell lines that are deficient in protein kinase A activity. Further, simultaneous treatment of wild-type CHO cells, with MNNG and to elevate cAMP, failed to result in an additive effect for activation of the /-pol promoter. Thus, these effectors may act through a common pathway. These results suggest that the activation of the cloned β-pol promoter in CHO cells following MNNG treatment is mediated through the cAMP/protein kinase A signal transduction pathway.
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U2 - 10.1093/nar/20.21.5527
DO - 10.1093/nar/20.21.5527
M3 - Article
C2 - 1454516
AN - SCOPUS:0026484398
SN - 0305-1048
VL - 20
SP - 5527
EP - 5531
JO - Nucleic Acids Research
JF - Nucleic Acids Research
IS - 21
ER -