Fred Hutchinson Cancer Center

University of Washington

The University of Arizona

Leland H Hartwell

Stephen H Friend

Mark T Groudine

Ted A Weinert

Sharon E Plon

The present invention provides methods for identifying targets of a drug in a cell by comparing (i) the effects of the drug on a wild-type cell, (ii) the effects on a wild-type cell of modifications to a putative target of the drug, and (iii) the effects of the drug on a wild-type cell which has had the putative target modified of the drug. In various embodiments, the effects on the cell can be determined by measuring gene expression, protein abundances, protein activities, or a combination of such measurements. In various embodiments, modifications to a putative target in the cell can be made by modifications to the genes encoding the target, modification to abundances of RNAs encoding the target, modifications to abundances of target proteins, or modifications to activities of the target proteins. The present invention also provides methods for drug development based on the methods for identifying drug targets.

Methods for drug target screening

Human checkpoint huCDC34, huRAD9.sub.compA, and huRAD9.sub.compB cDNAs shown in FIGS. 1, 2, and 3. A method for isolating a human checkpoint cDNA that is capable of restoring growth at a restrictive temperature in a yeast test cell, wherein the yeast test cell comprises a genome having a first gene that forms a DNA strand break at a restrictive temperature and a second gene that fails to induce a cell cycle arrest in response to the DNA strand break, whereby the growth of the yeast test cell is inhibited at the restrictive temperature, the method comprising the steps of: obtaining a human cDNA library comprising a plurality of human cDNA clones; inserting the human cDNA clones individually into plasmid vectors comprising a selectable marker gene; transforming a culture of the yeast test cells with the plasmid vectors from the preceding step; selecting for yeast test cells transformed with the selectable marker gene; growing the selected transformants at the restrictive temperature and isolating a candidate transformant capable of growing at the restrictive temperature; and identifying the human cDNA carried by the candidate transformant as a human checkpoint cDNA by sequencing the human cDNA carried by the candidate transformant and determining that the human cDNA is less than 50% homologous with both the first gene and the second gene. Also yeast checkpoint RAD17, RAD24, MEC1, MEC2, and MEC3 cDNAs shown in FIGS. 4-8.

Cell cycle checkpoint genes

Human checkpoint huCDC34, huRAD9.sub.compA, and huRAD9.sub.compB cDNAs shown in SEQ ID Nos:7-9. A method for isolating a human checkpoint cDNA that is capable of restoring growth at a restrictive temperature in a yeast test cell, wherein the yeast test cell comprises a genome having a first gene that forms a DNA strand break at a restrictive temperature and a second gene that fails to induce a cell cycle arrest in response to the DNA strand break, whereby the growth of the yeast test cell is inhibited at the restrictive temperature, the method comprising the steps of: obtaining a human cDNA library comprising a plurality of human cDNA clones; inserting the human cDNA clones individually into plasmid vectors comprising a selectable marker gene; transforming a culture of the yeast test cells with the plasmid vectors from the preceding step; selecting for yeast test cells transformed with the selectable marker gene; growing the selected transformants at the restrictive temperature and isolating a candidate transformant capable of growing at the restrictive temperature; and identifying the human cDNA carried by the candidate transformant as a human checkpoint cDNA by sequencing the human cDNA carried by the candidate transformant and determining that the human cDNA is less than 50% homologous with both the first gene and the second gene. Also yeast checkpoint RAD17, RAD24, MEC1, MEC2, and MEC3 cDNAs shown in SEQ ID Nos:10-19.

Growing community of inventors

Seattle, WA, United States of America

Leland H Hartwell