Reference: Walsh L, et al. (2005) Genetic modification and variations in solvent increase the sensitivity of the yeast RAD54-GFP genotoxicity assay. Mutagenesis 20(5):317-27

Reference Help

Abstract


The yeast (Saccharomyces cerevisiae) RAD54-GFP DNA repair reporter assay (GreenScreen assay, GSA) can be used for early genotoxicity screening in drug discovery. During the initial validation of this preregulatory assay, a subset of known genotoxic compounds that did not give reproducibly clear positive GSA results was identified. Cell permeability, inherent drug resistance mechanisms, metabolic activation and compound solubility were identified as possible barriers to the detection of specific compounds. In this study three types of modification to the existing assay protocol were explored in order to address these possibilities: (i) modification of the reporter host strain by deletion of genes involved in cell wall integrity or with products functioning as efflux pumps (PDR5, ERG6, SNQ2, YOR1); (ii) expression in the host yeast of human phase I metabolic activation genes and (iii) variation in the test solvent system for compounds with poor aqueous solubility. The modifications described and the assay results presented show how the assay may be tailored to suit specific classes of test compound in a more analytical mode. Improvements in assay sensitivity were seen in the detection of some genotoxins using yeast cell wall mutants and those expressing human cytochrome P450 genes.

Reference Type
Journal Article | Research Support, Non-U.S. Gov't
Authors
Walsh L, Hastwell PW, Keenan PO, Knight AW, Billinton N, Walmsley RM
Primary Lit For
Additional Lit For
Review For

Gene Ontology Annotations


Increase the total number of rows showing on this page using the pull-down located below the table, or use the page scroll at the table's top right to browse through the table's pages; use the arrows to the right of a column header to sort by that column; filter the table using the "Filter" box at the top of the table.

Gene/Complex Qualifier Gene Ontology Term Aspect Annotation Extension Evidence Method Source Assigned On Reference

Phenotype Annotations


Increase the total number of rows showing on this page using the pull-down located below the table, or use the page scroll at the table's top right to browse through the table's pages; use the arrows to the right of a column header to sort by that column; filter the table using the "Filter" box at the top of the table; click on the small "i" buttons located within a cell for an annotation to view further details.

Gene Phenotype Experiment Type Mutant Information Strain Background Chemical Details Reference

Disease Annotations


Increase the total number of rows showing on this page using the pull-down located below the table, or use the page scroll at the table's top right to browse through the table's pages; use the arrows to the right of a column header to sort by that column; filter the table using the "Filter" box at the top of the table.

Gene Disease Ontology Term Qualifier Evidence Method Source Assigned On Reference

Regulation Annotations


Increase the total number of rows displayed on this page using the pull-down located below the table, or use the page scroll at the table's top right to browse through the table's pages; use the arrows to the right of a column header to sort by that column; to filter the table by a specific experiment type, type a keyword into the Filter box (for example, “microarray”); download this table as a .txt file using the Download button or click Analyze to further view and analyze the list of target genes using GO Term Finder, GO Slim Mapper, SPELL, or YeastMine.

Regulator Target Direction Regulation Of Happens During Method Evidence

Post-translational Modifications


Increase the total number of rows showing on this page by using the pull-down located below the table, or use the page scroll at the table's top right to browse through its pages; use the arrows to the right of a column header to sort by that column; filter the table using the "Filter" box at the top of the table.

Site Modification Modifier Reference

Interaction Annotations


Genetic Interactions

Increase the total number of rows showing on this page by using the pull-down located below the table, or use the page scroll at the table's top right to browse through the table's pages; use the arrows to the right of a column header to sort by that column; filter the table using the "Filter" box at the top of the table; click on the small "i" buttons located within a cell for an annotation to view further details about experiment type and any other genes involved in the interaction.

Interactor Interactor Allele Assay Annotation Action Phenotype SGA score P-value Source Reference

Physical Interactions

Increase the total number of rows showing on this page by using the pull-down located below the table, or use the page scroll at the table's top right to browse through the table's pages; use the arrows to the right of a column header to sort by that column; filter the table using the "Filter" box at the top of the table; click on the small "i" buttons located within a cell for an annotation to view further details about experiment type and any other genes involved in the interaction.

Interactor Interactor Assay Annotation Action Modification Source Reference

Functional Complementation Annotations


Increase the total number of rows showing on this page by using the pull-down located below the table, or use the page scroll at the table's top right to browse through its pages; use the arrows to the right of a column header to sort by that column; filter the table using the "Filter" box at the top of the table.

Gene Species Gene ID Strain background Direction Details Source Reference