Neurofibromatosis type 1 (NF1), one of the most common inherited diseases, represents a challenge to both clinicians and basic scientists. The protean nature of the disorder and its variable expressivity has made presymptomatic clinical diagnosis difficult and treatment unsatisfactory. The neurofibromatosis gene is thought to behave as a tumor suppressor gene and a better understanding of its role in normal cell biology will provide insights not only into tumor biology but also the mechanisms underlying normal growth and development. Progress in appreciating the function of the NF1 gene will require the identification and characterization of the gene product of the NF1 locus. The work outlined in this grant proposal is directed towards characterizing the NF1 protein and determining its normal function in order to better understand how diseases like NF1 results from abnormalities of the NF1 protein.
The specific aims of this project are directed at characterizing the NF1 gene product: (1) Antibodies will be generated to identify the NF1 protein (NF1 GAP-related protein, NF1GRP). These antibodies will provide reagents to determine functional and structural domains of NF1GRP as well as to define its subcellular and tissue distribution. Proteins which associate with NF1GRP will be isolated by the combined approaches of coimmunoprecipitation using these antibodies and column chromatography using baculovirus-expressed NF1GRP matrices. (2) Analysis of the complete NF1 cDNA sequence has demonstrated sequence similarity between a 400 amino acid region of NF1GRP (catalytic domain) and a family of GTPase-activating proteins. There is nothing known about the remaining 85% of the protein. Site-directed mutagenesis and domain swapping experiments will be undertaken to investigate the role of the catalytic as well as noncatalytic domain regions in NF1GRP function. (3) Recent studies have demonstrated that NF1GRP may be expressed in all tissues. In order to determine what role NF1GRP has in non-neural crest tissues, the Drosophila NF1 homolog will be cloned and studied. Its pattern of expression in adult tissues as well as during the course of Drosophila nervous system development will be investigated. Drosophila provides a unique model system for studying NF1GRP given the relative simplicity of the fruitfly genome, the wealth of information on nervous system development and the ability to determine the impact of NF1GRP on development by direct mutagenesis and through the study of known developmental mutants.

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Clinical Investigator Award (CIA) (K08)
Project #
7K08NS001590-03
Application #
3084754
Study Section
NST-2 Subcommittee (NST)
Project Start
1992-07-01
Project End
1997-06-30
Budget Start
1993-09-29
Budget End
1994-06-30
Support Year
3
Fiscal Year
1993
Total Cost
Indirect Cost
Name
Washington University
Department
Type
Schools of Medicine
DUNS #
062761671
City
Saint Louis
State
MO
Country
United States
Zip Code
63130
Saporito-Irwin, S M; Geist, R T; Gutmann, D H (1997) Ammonium acetate protocol for the preparation of plasmid DNA suitable for mammalian cell transfections. Biotechniques 23:424-7
Gutmann, D H; Giordano, M J; Mahadeo, D K et al. (1996) Increased neurofibromatosis 1 gene expression in astrocytic tumors: positive regulation by p21-ras. Oncogene 12:2121-7
Guha, A; Lau, N; Huvar, I et al. (1996) Ras-GTP levels are elevated in human NF1 peripheral nerve tumors. Oncogene 12:507-13
Geist, R T; Gutmann, D H (1996) Expression of a developmentally-regulated neuron-specific isoform of the neurofibromatosis 1 (NF1) gene. Neurosci Lett 211:85-8
Gutmann, D H; Geist, R T; Wright, D E et al. (1995) Expression of the neurofibromatosis 1 (NF1) isoforms in developing and adult rat tissues. Cell Growth Differ 6:315-23
Gutmann, D H; Cole, J L; Collins, F S (1995) Expression of the neurofibromatosis type 1 (NF1) gene during mouse embryonic development. Prog Brain Res 105:327-35
Gutmann, D H; Silos-Santiago, I; Geist, R T et al. (1995) Lack of NF1 expression in a sporadic schwannoma from a patient without neurofibromatosis. J Neurooncol 25:103-11
Hewett, S J; Choi, D W; Gutmann, D H (1995) Expression of the neurofibromatosis 1 (NF1) gene in reactive astrocytes in vitro. Neuroreport 6:1565-8
Gutmann, D H; Wright, D E; Geist, R T et al. (1995) Expression of the neurofibromatosis 2 (NF2) gene isoforms during rat embryonic development. Hum Mol Genet 4:471-8
Gutmann, D H; Geist, R T; Rose, K et al. (1995) Expression of two new protein isoforms of the neurofibromatosis type 1 gene product, neurofibromin, in muscle tissues. Dev Dyn 202:302-11

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