The fos protein is a nuclear, DNA binding protein which is a transcription regulator and is induced in a wide range of cell types by many different transmembrane signals, including growth factor stimulation. Recently, it has been shown that fos makes a specific complex with the jun protein through interactions of alpha helical regions containing heptad repeats of leucines (leucine zipper). The zipper interaction juxtaposes basic amino acid motifs of both proteins which form a sequence specific DNA binding domain. We propose to determine the structural features of fos which give specificity for heterodimerization with jun. These could reside within the alpha helix, or elsewhere, and will be analyzed by the method of site directed mutagenesis and in vitro assay of reticulocyte lysate translation products. We have also shown that when nerve growth factor (NGF) stimulates model PC12 pheochromocytoma cells to differentiate down a neuronal pathway, fos is induced. Peak fos transcription is 30 min. post NGF. Following fos induction, other genes which express neuronal specific functions are also expressed. One of these, the tyrosien hydroxylase (TH) gene, is induced transcriptionally 1 hr. following NGF treatment. The TH promoter has a DNA element which binds authentic fos-jun complex and also binds an in vivo PC12 product which is induced by NGF over the period 1-4 hr post treatment. This is the same interval over which TH transcription is positively and negatively regulated. We will analyze the induced PC12 for factors which may regulate TH expression. This will include identification of the factor)s) which interact with the TH gene promoter, analysis of the particular role of fos, and a search for new, neuronal-specific members of the fos and jun families. Thus, the Specific Aims of the proposal are:
Aim 1. To determine the structural features of fos which confer specificity of heterodimerization on the fos and jun proteins.
Aim 2. To determine the role of the immediate early response genes (including the fos family members) in regulation of transcription of delayed early genes in PC12 cells.

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Research Project (R01)
Project #
2R01CA044042-04
Application #
3186555
Study Section
Molecular Biology Study Section (MBY)
Project Start
1987-02-01
Project End
1995-01-31
Budget Start
1990-02-01
Budget End
1991-01-31
Support Year
4
Fiscal Year
1990
Total Cost
Indirect Cost
Name
New York University
Department
Type
Schools of Medicine
DUNS #
004514360
City
New York
State
NY
Country
United States
Zip Code
10012
MacGregor, D; Li, L H; Ziff, E B (1996) Dominant negative mutants of Myc inhibit cooperation of both Myc and adenovirus serotype-5 E1a with Ras. J Cell Physiol 167:95-105
Hopewell, R; Ziff, E B (1995) The nerve growth factor-responsive PC12 cell line does not express the Myc dimerization partner Max. Mol Cell Biol 15:3470-8
Kerkhoff, E; Ziff, E B (1995) Deregulated messenger RNA expression during T cell apoptosis. Nucleic Acids Res 23:4857-63
Nerlov, C; Ziff, E B (1994) Three levels of functional interaction determine the activity of CCAAT/enhancer binding protein-alpha on the serum albumin promoter. Genes Dev 8:350-62
Gizang-Ginsberg, E; Ziff, E B (1994) Fos family members successively occupy the tyrosine hydroxylase gene AP-1 site after nerve growth factor or epidermal growth factor stimulation and can repress transcription. Mol Endocrinol 8:249-62
Li, L H; Nerlov, C; Prendergast, G et al. (1994) c-Myc represses transcription in vivo by a novel mechanism dependent on the initiator element and Myc box II. EMBO J 13:4070-9
Prendergast, G C; Hopewell, R; Gorham, B J et al. (1992) Biphasic effect of Max on Myc cotransformation activity and dependence on amino- and carboxy-terminal Max functions. Genes Dev 6:2429-39
Metz, R; Ziff, E (1991) cAMP stimulates the C/EBP-related transcription factor rNFIL-6 to trans-locate to the nucleus and induce c-fos transcription. Genes Dev 5:1754-66
Metz, R; Ziff, E (1991) The helix-loop-helix protein rE12 and the C/EBP-related factor rNFIL-6 bind to neighboring sites within the c-fos serum response element. Oncogene 6:2165-78
Gizang-Ginsberg, E; Ziff, E B (1990) Nerve growth factor regulates tyrosine hydroxylase gene transcription through a nucleoprotein complex that contains c-Fos. Genes Dev 4:477-91

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