Disorders of purine metabolism occur in about 5% of the population and may eventually lead to clinical disease in 1%. The clinical manifestations of these disorders range from gout to severe combined immunodeficiency disease. Despite the importance of derangements in this pathway to the pathogenesis of human disease, it now appears that a better understanding of some of those disorders at the most fundamental levels may have even broader implications to the progress of biomedical science. In the present investigation, we will focus on a) defining the nature and consequences of the specific mutations occurring spontaneously in humans which alter the expression of hypoxanthine guanine phosphoribosyltransferase (HPRT) and adenine phosphoribosyltransferase (APRT), b) developing an approach to inserting the HPRT complementary DNA into neuronal cells in culture using a modified neurotropic virus as the vector, and c) elucidating in the brain the normal role of HPRT as well as the metabolic aberrations resulting from its deficiency. During the tenure of this grant we propose to exploit the most advanced scientific techniques and experimental approaches available ranging from the highly sophisticated tools of the basic biochemist to the complex but highly powerful instrumentation utilized by the skilled clinician. Specifically, our approach will utilize a) recombinant DNA techniques involving cDNA cloning and sequencing, construction of useful chimeric plasmids and site directed mutagenesis, b) highly sophisticated methodology at the level of the protein including X-ray crystallography, immunocytochemical localization, and, as necessary, microsequencing and monoclonal antibody techniques, and c) at the bedside, Positron Emission Tomography (PET). Our work on the Regulation of Purine Metabolism in Human Cells has moved over the years from the bedside to the cell to the protein and now to the gene as well as back to the bedside. It is our expectation that these studies will not only substantially expand our information base related to the specific diseases associated with a deficiency of HPRT (Lesch-Nyhan syndrome; Gout) and APRT (2,8 dihydroxyadenine stone disease), but also will provide important information on human gene and protein structure and function as well as on gene transfer particularly in the neurologic diseases.

Agency
National Institute of Health (NIH)
Institute
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Type
Research Project (R01)
Project #
5R01DK019045-12
Application #
3226255
Study Section
Biochemistry Study Section (BIO)
Project Start
1975-09-15
Project End
1990-08-31
Budget Start
1986-09-01
Budget End
1987-08-31
Support Year
12
Fiscal Year
1986
Total Cost
Indirect Cost
Name
University of Michigan Ann Arbor
Department
Type
Schools of Medicine
DUNS #
791277940
City
Ann Arbor
State
MI
Country
United States
Zip Code
48109
Davidson, B L; Golovoy, N; Roessler, B J (1994) A 13 base pair deletion in exon 1 of HPRTIllinois forms a functional GUG initiation codon. Hum Genet 93:300-4
Davidson, B L; Tarle, S A; Van Antwerp, M et al. (1991) Identification of 17 independent mutations responsible for human hypoxanthine-guanine phosphoribosyltransferase (HPRT) deficiency. Am J Hum Genet 48:951-8
Mimori, A; Hidaka, Y; Wu, V C et al. (1991) A mutant allele common to the type I adenine phosphoribosyltransferase deficiency in Japanese subjects. Am J Hum Genet 48:103-7
Tarle, S A; Davidson, B L; Wu, V C et al. (1991) Determination of the mutations responsible for the Lesch-Nyhan syndrome in 17 subjects. Genomics 10:499-501
Palella, T D; Hidaka, Y; Silverman, L J et al. (1989) Expression of human HPRT mRNA in brains of mice infected with a recombinant herpes simplex virus-1 vector. Gene 80:137-44
Davidson, B L; Tarle, S A; Palella, T D et al. (1989) Molecular basis of hypoxanthine-guanine phosphoribosyltransferase deficiency in ten subjects determined by direct sequencing of amplified transcripts. J Clin Invest 84:342-6
Fujimori, S; Davidson, B L; Kelley, W N et al. (1989) Identification of a single nucleotide change in the hypoxanthine-guanine phosphoribosyltransferase gene (HPRTYale) responsible for Lesch-Nyhan syndrome. J Clin Invest 83:11-3
Hidaka, Y; Kelley, W N; Levine, M et al. (1989) Expression of human hypoxanthine guanine phosphoribosyltransferase mRNA in brains of mice infected with a recombinant herpes simplex virus type 1. Trans Assoc Am Physicians 102:91-100
Davidson, B L; Pashmforoush, M; Kelley, W N et al. (1989) Human hypoxanthine-guanine phosphoribosyltransferase deficiency. The molecular defect in a patient with gout (HPRTAshville). J Biol Chem 264:520-5
Davidson, B L; Chin, S J; Wilson, J M et al. (1988) Hypoxanthine-guanine phosphoribosyltransferase. Genetic evidence for identical mutations in two partially deficient subjects. J Clin Invest 82:2164-7

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