This project is concerned with the tumor-inducing pTiC58 plasmid of Agrobacterium tumefaciens. The pTiC58 plasmid contains the information required for virulence and oncogenicity. This information is contained in two regions of pTiC58. Work is focused on these regions and involves determining: (1) the number of genes required for virulence and oncogenicity; (2) the precise location of these genes; (3) the mechanism by which these genes are regulated; and (4) the identification of the products of these genes. We are also constructing a protein map relative to the position of these genes by using a homologous coupled transcription-translation system, immunologic probes, and newly constructed amplifiable cloning plasmid cloning and expression vectors. Each of the genes of the Vir region so far studied are absolutely essential for virulence and oncogenicity. We have discovered that some of these genes are regulated by the inducer indole-3-acetic acid, while others are regulated by an unidentified substance which is elaborated by the plant during active cell division. The identification of inducers and the construction of gene fusions has allowed us for the first time to determine the timing and mechanism by which Vir genes are switched on during early stages of bacterial-plant interactions leading to tumor formation. We are extending similar efforts to the T-region, particularly on the regulation of genes that remain silent in the bacterium but are expressed in the eukaryotic plant cell. Studies are also being made on the precise location of the virulence suppressive genes contained in plasmid pSa and the products of these genes. Also, additional work is being done on characterizing plasmid pTAR and its origin of replication. (R)

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Research Project (R01)
Project #
5R01CA011526-20
Application #
3163492
Study Section
Microbial Physiology and Genetics Subcommittee 2 (MBC)
Project Start
1979-09-01
Project End
1991-03-31
Budget Start
1989-09-01
Budget End
1991-03-31
Support Year
20
Fiscal Year
1989
Total Cost
Indirect Cost
Name
University of California Davis
Department
Type
Earth Sciences/Resources
DUNS #
094878337
City
Davis
State
CA
Country
United States
Zip Code
95618
Thomenius, Kai E; Wodnicki, Robert; Cogan, Scott D et al. (2014) Reconfigurable mosaic annular arrays. IEEE Trans Ultrason Ferroelectr Freq Control 61:1086-100
Close, S M; Kado, C I (1992) A gene near the plasmid pSa origin of replication encodes a nuclease. Mol Microbiol 6:521-7
Okumura, M S; Kado, C I (1992) The region essential for efficient autonomous replication of pSa in Escherichia coli. Mol Gen Genet 235:55-63
Close, S M; Kado, C I (1991) The osa gene of pSa encodes a 21.1-kilodalton protein that suppresses Agrobacterium tumefaciens oncogenicity. J Bacteriol 173:5449-56
Cooley, M B; D'Souza, M R; Kado, C I (1991) The virC and virD operons of the Agrobacterium Ti plasmid are regulated by the ros chromosomal gene: analysis of the cloned ros gene. J Bacteriol 173:2608-16
Powell, B S; Kado, C I (1990) Specific binding of VirG to the vir box requires a C-terminal domain and exhibits a minimum concentration threshold. Mol Microbiol 4:2159-66
Murray, I A; Martinez-Suarez, J V; Close, T J et al. (1990) Nucleotide sequences of genes encoding the type II chloramphenicol acetyltransferases of Escherichia coli and Haemophilus influenzae, which are sensitive to inhibition by thiol-reactive reagents. Biochem J 272:505-10
Steck, T R; Kado, C I (1990) Virulence genes promote conjugative transfer of the Ti plasmid between Agrobacterium strains. J Bacteriol 172:2191-3
Rogowsky, P M; Powell, B S; Shirasu, K et al. (1990) Molecular characterization of the vir regulon of Agrobacterium tumefaciens: complete nucleotide sequence and gene organization of the 28.63-kbp regulon cloned as a single unit. Plasmid 23:85-106
Shirasu, K; Morel, P; Kado, C I (1990) Characterization of the virB operon of an Agrobacterium tumefaciens Ti plasmid: nucleotide sequence and protein analysis. Mol Microbiol 4:1153-63

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