Abstract

The overall objective of this project is to elucidate the regulation and genetics of ornithine decarboxylase (ODC), the initial and rate-limiting enzyme in the pathway of polyamine biosynthesis. We have selected mouse cells that overproduce the enzyme as a result of gene amplification, and we have used the overproducing cells to generate ODC cDNA clones. We now propose the following experiments. ODC activity can be made to change markedly in response to hormones, polyamines, tumor promotors, oncogenic transformation, and changes in cell growth state. We will determine the molecular mechanisms of that regulation. mRNA levels will be determined and the contribution of transcription rate and mRNA turnover to those levels measured. Protein stability and regulable alterations of that stability will be examined. Post-translational modifications that affect enzyme activity will be examined. Regulation of endogenous ODC will be studied in wild-type and mutant S49 mouse lymphoma cells (response to polyamines, cyclic AMP analogues), PC12 rat pheochromocytoma cells (response to cyclic AMP analogues and nerve growth factor), and mouse 3T3 fibroblasts (response to tumor promotors and epidermal growth factor). Using recombinant DNA techniques, expression vectors containing the ODC gene or portions of that gene will be constructed, recipient cells transformed, and expression of those constructs assessed. ODC in mouse constitutes a multi-gene family. We will determine whether these genes are clustered, establish a chromosomal assignment for the active gene or genes and find out whether pseudo-genes exist. Somatic mutants that are altered in ODC regulation will be generated. S49 cell mutants that overproduce ODC will be further charcterized genetically. Revertants of those mutants will be selected in an effort to obtain suppressor regulatory mutations. Mutants that are deficient for ODC expression will be sought. (B)

  Funding Agency

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Research Project (R01)
Project #
5R01CA029048-07
Application #
3168486
Study Section
Pathology B Study Section (PTHB)
Project Start
1982-02-01
Project End
1990-01-31
Budget Start
1988-02-01
Budget End
1989-01-31
Support Year
7
Fiscal Year
1988
Total Cost
Indirect Cost

  Institution

Name
University of California San Francisco
Department
Type
Schools of Medicine
DUNS #
073133571
City
San Francisco
State
CA
Country
United States
Zip Code
94143

  Publications

Poznanski, A; Keller, R (1997) The role of planar and early vertical signaling in patterning the expression of Hoxb-1 in Xenopus. Dev Biol 184:351-66
Kern, A; Oliveira, M A; Chang, N L et al. (1996) Crystallization of a mammalian ornithine decarboxylase. Proteins 24:266-8
Macrae, M; Plasterk, R H; Coffino, P (1995) The ornithine decarboxylase gene of Caenorhabditis elegans: cloning, mapping and mutagenesis. Genetics 140:517-25
Li, X; Coffino, P (1994) Distinct domains of antizyme required for binding and proteolysis of ornithine decarboxylase. Mol Cell Biol 14:87-92
Tsirka, S E; Turck, C W; Coffino, P (1993) Multiple active conformers of mouse ornithine decarboxylase. Biochem J 293 ( Pt 1):289-95
Li, X; Coffino, P (1993) Degradation of ornithine decarboxylase: exposure of the C-terminal target by a polyamine-inducible inhibitory protein. Mol Cell Biol 13:2377-83
Li, X; Coffino, P (1992) Regulated degradation of ornithine decarboxylase requires interaction with the polyamine-inducible protein antizyme. Mol Cell Biol 12:3556-62
Tsirka, S; Coffino, P (1992) Dominant negative mutants of ornithine decarboxylase. J Biol Chem 267:23057-62
Ghoda, L; Sidney, D; Macrae, M et al. (1992) Structural elements of ornithine decarboxylase required for intracellular degradation and polyamine-dependent regulation. Mol Cell Biol 12:2178-85
Coffino, P; Poznanski, A (1991) Killer polyamines? J Cell Biochem 45:54-8

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