The overall research objective of this laboratory is to understand the mechanism of regulation of cytochrome P450IA1, a monooxygenase that functions in the activation of polycyclic hydrocarbons, such as benzo (a) pyrene (BP). We have postulated that a cytosolic 4S polycyclic hydrocarbon-binding protein functions as a trans-activator of the P45OIA1 gene.
The specific aims of this proposal relate to this hypothesis.
The specific aims are to: a) determine the amino acid sequence of the 4S polycyclic hydrocarbon-binding protein, produce polyclonal antibodies to this protein, and determine if phosphorylation and/or conjunction with hsp90 can modify its activity; b) ascertain the nature of the 5'-upstream regions of the P450IA1 gene to which the 4s protein binds, i.e., polycyclic hydrocarbon responsive elements (PRE's), and establish by in vitro nuclear transcriptional assays that the 4s protein is a trans-activator of this gene; c) isolate the 4s protein gene from liver cDNA and genomic libraries and characterize this gene, and d) determine the effects of transfection of vectors that would transcribe antisense to the 4s gene and of introduction of antibodies to the 4s protein on the induction of the P450IA1 gene in response to BP treatment. These studies should establish a central role for the 4s polycyclic hydrocarbon-binding protein in the regulation of the expression of the P450IA1 gene.

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Research Project (R01)
Project #
5R01CA036106-10
Application #
3173603
Study Section
Chemical Pathology Study Section (CPA)
Project Start
1988-05-01
Project End
1994-07-31
Budget Start
1992-08-01
Budget End
1993-07-31
Support Year
10
Fiscal Year
1992
Total Cost
Indirect Cost
Name
Dartmouth College
Department
Type
Schools of Medicine
DUNS #
041027822
City
Hanover
State
NH
Country
United States
Zip Code
03755
Bhat, R; Wagner, C; Bresnick, E (1997) The homodimeric form of glycine N-methyltransferase acts as a polycyclic aromatic hydrocarbon-binding receptor. Biochemistry 36:9906-10
Bhat, R; Weaver, J A; Sterling, K M et al. (1996) Nuclear transcription factor Oct-1 binds to the 5'-upstream region of CYP1A1 and negatively regulates its expression. Int J Biochem Cell Biol 28:217-27
Sterling, K; Bresnick, E (1996) Oct-1 transcription factor is a negative regulator of rat CYP1A1 expression via an octamer sequence in its negative regulatory element. Mol Pharmacol 49:329-37
Raha, A; Joyce, T; Gusky, S et al. (1995) Glycine N-methyltransferase is a mediator of cytochrome P4501A1 gene expression. Arch Biochem Biophys 322:395-404
Sterling, K; Raha, A; Bresnick, E (1994) Induction of CYP1A1 gene expression in mouse hepatoma cells by benzo[e]pyrene, a ligand of the 4S polycyclic hydrocarbon-binding protein. Toxicol Appl Pharmacol 128:18-24
Raha, A; Wagner, C; MacDonald, R G et al. (1994) Rat liver cytosolic 4 S polycyclic aromatic hydrocarbon-binding protein is glycine N-methyltransferase. J Biol Chem 269:5750-6
Chung, I; Bresnick, E (1994) 3-Methylcholanthrene-mediated induction of cytochrome P4501A2 in human hepatoma HepG2 cells as quantified by the reverse transcription-polymerase chain reaction. Arch Biochem Biophys 314:75-81
Xu, L C; Sinclair, P R; Bresnick, E (1993) Induction of cytochrome P450IA1 and its recombinant construct in H4IIE rat hepatoma cells. Int J Biochem 25:13-21
Sterling, K; Weaver, J; Ho, K L et al. (1993) Rat CYP1A1 negative regulatory element: biological activity and interaction with a protein from liver and hepatoma cells. Mol Pharmacol 44:560-8
Raha, A; Reddy, V; Xu, L C et al. (1991) Presence of the 4 S polycyclic hydrocarbon-binding protein in H4-II-E cells. Toxicology 66:175-86

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