Mitotically dividing mammalian cells possess the recombinataional machinery to catalyze a number of different types of DNA rearrangements that can alter either the expression of genes or their spatial configuration. Until recently, these events have been difficult to analyze because suitable genetic and model systems have not been available to probe these multiple recombinational activities. As a consequence, very little is known about the mechanisms or enzymology of recombination, even though these processes are likely to be important for the proper functioning of most cells. Our approach to this problem has been to use simple model systems, based on recombination substrates constructed in vitro to analyze different recombination events. These substrates are eukaryotic expression vectors containing either truncated or mutant copies of dominant selectable marker genes, such that reciprocal recombination or gene conversion restores a functional copy of the gene, following transient infection or stable integration of these substrate DNAs into appropriate cells. We are interested in studying the frequencies and mechanisms of extrachromosomal, intrachromosomal and interchromosomal, reciprocal and non-reciprocal recombination. Because extrachromosomal recombination of newly transfected DNA appears to be much more frequent than chromosomal recombination, we wish to determine the basis for these different frequencies. Gap repair and its possible applications will be explored. Among our long term interests are the exchange of genetic information between the chromosome and extrachromosomal plasmids, as well as the enzymology of recombination. We therefore plan to explore methods for gene targeting and gene recovery and hope to develop an in vitro system to study recombination. Many of the assays for reciprocal and non-reciprocal events will also be extended to human cells including those that are believed to be aberrant in recombination and repair, and the effect of drugs and DNA damaging agents will be evaluated. We hope that the study of these basic processes will contribute to a better understanding of how recombination occurs and how it might be modulated in mammalian cells.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM031253-06
Application #
3279182
Study Section
Mammalian Genetics Study Section (MGN)
Project Start
1982-07-01
Project End
1990-06-30
Budget Start
1987-07-01
Budget End
1988-06-30
Support Year
6
Fiscal Year
1987
Total Cost
Indirect Cost
Name
University of California San Diego
Department
Type
Schools of Arts and Sciences
DUNS #
077758407
City
La Jolla
State
CA
Country
United States
Zip Code
92093
Lenormand, J L; Dellinger, R W; Knudsen, K E et al. (1999) Speedy: a novel cell cycle regulator of the G2/M transition. EMBO J 18:1869-77
Osman, F; Subramani, S (1998) Double-strand break-induced recombination in eukaryotes. Prog Nucleic Acid Res Mol Biol 58:263-99
Knudsen, K E; Knudsen, E S; Wang, J Y et al. (1996) p34cdc2 kinase activity is maintained upon activation of the replication checkpoint in Schizosaccharomyces pombe. Proc Natl Acad Sci U S A 93:8278-83
Fortunato, E A; Osman, F; Subramani, S (1996) Analysis of spontaneous and double-strand break-induced recombination in rad mutants of S. pombe. Mutat Res 364:14-60
Osman, F; Fortunato, E A; Subramani, S (1996) Double-strand break-induced mitotic intrachromosomal recombination in the fission yeast Schizosaccharomyces pombe. Genetics 142:341-57
Birkenbihl, R P; Subramani, S (1995) The rad21 gene product of Schizosaccharomyces pombe is a nuclear, cell cycle-regulated phosphoprotein. J Biol Chem 270:7703-11
Kanter-Smoler, G; Knudsen, K E; Jimenez, G et al. (1995) Separation of phenotypes in mutant alleles of the Schizosaccharomyces pombe cell-cycle checkpoint gene rad1+. Mol Biol Cell 6:1793-805
Long, K E; Sunnerhagen, P; Subramani, S (1994) The Schizosaccharomyces pombe rad1 gene consists of three exons and the cDNA sequence is partially homologous to the Ustilago maydis REC1 cDNA. Gene 148:155-9
Carr, A M; Schmidt, H; Kirchhoff, S et al. (1994) The rad16 gene of Schizosaccharomyces pombe: a homolog of the RAD1 gene of Saccharomyces cerevisiae. Mol Cell Biol 14:2029-40
Jimenez, G; Yucel, J; Rowley, R et al. (1992) The rad3+ gene of Schizosaccharomyces pombe is involved in multiple checkpoint functions and in DNA repair. Proc Natl Acad Sci U S A 89:4952-6

Showing the most recent 10 out of 23 publications