Chemical genetics target identification

Three Examples of Chemical Genetic Target Identification... 

Chemical Genetics, Target Site Identification, Resistant Mutants, Herbicide Mode of Action, Auxins, Arahidopsis... 

In eukaryotes, translation initiation is rate-limiting with much regulation exerted at the ribosome recruitment and ternary complex (elF2 GTP Met-tRNAjMet) formation steps. Although small molecule inhibitors have been extremely useful for chemically dissecting translation, there is a dearth of compounds available to study the initiation phase in vitro and in vivo. In this chapter, we describe reverse and forward chemical genetic screens developed to identify new inhibitors of translation. The ability to manipulate cell extracts biochemically, and to compare the activity of small molecules on translation of mRNA templates that differ in their factor requirements for ribosome recruitment, facilitates identification of the relevant target. 

The application of forward chemical genetics to studies of translation provides an opportunity to identify small molecules that inhibit or stimulate this process without any underlying assumptions as to which step is most amenable to targeting by the chemical libraries under consideration. The opportunity exists to identify novel factors involved in translation, unravel new activities of known translation initiation factors, or characterize shortlived intermediates that are frozen by the small molecule inhibitor. We have undertaken a forward chemical genetic approach to identify small molecules that inhibit or stimulate translation in extracts prepared from Krebs-2 ascites cells (Novae et al., 2004). These screens have led to the identification of several novel inhibitors of translation initiation and elongation (Bordeleau et al., 2005, 2006 Robert et al., 2006a,b). 

This work elegantly demonstrates power of combined ABPP and chemical genetics approaches in understanding microbial pathogenesis, and has made a very real contribution to the identification of potential novel dmg targets. 

Chemical Genetics - How Chemistry Can Contribute to Target Identification and Validation... 

Burdine L, Kodadek T. Target identification in chemical genetics The (often) missing link. Chem. Biol. 2004 11 593-597. 

Fig. 6-9 Target identification of a suppressor of rapamycin [42]. (a) SMIR4 a suppressor of rapamycin identified using a chemical-genetic modifier screen, (b) Identification of gene products that interact with biotin-SMIR4 using a yeast protein microarray [42].

G.P. Tochtrop, R.W. King, Target identification strategies in chemical genetics, Comb. Chem. High Throughput Screen. 2004, 7, 677-688. 

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