AID	Name	Type	Comment
588636	qHTS for Inhibitors of Polymerase Eta: Summary	summary

The Y-family of DNA polymerases, such as Pol eta, are specifically involved in DNA repair. Pol eta copies undamaged DNA with a lower fidelity than other DNA-directed polymerases. However, it accurately replicates UV-damaged DNA; when thymine dimers are present, this polymerase inserts the complementary nucleotides in the newly synthesized DNA, thereby bypassing the lesion and suppressing the mutagenic effect of UV-induced DNA damage. Pol eta has the ability to bypass cisplatinated DNA adducts in vitro, and it has been suggested that pol eta-dependent bypass of the cisplatin lesion in vivo leads to increased tumor resistance. Thus, while pol eta's (and most likely iota's) normal function is to protect humans against the deleterious consequences of DNA damage, under certain conditions they can have deleterious effects on human health. As a consequence, we propose to utilize a high throughput replication assay to identify small molecule inhibitors of pol eta.

In a collaboration between the National Institute of Child Health & Human Development (NICHD) and NIH Chemical Genomics Center, a high-throughput, fluorescent screen was developed to screen the NIH Molecular Libraries Small Molecule Repository (MLSMR). This screen is used to identify inhibitors of pol eta.

NIH Chemical Genomics Center [NCGC]
NIH Molecular Libraries Probe Centers Network [MLPCN]

MLPCN Grant: MH090825
Assay Submitter (PI): Roger Woodgate, NICHD)

Three microliters of reagents (buffer in column 3 and 4 as negative control and 10 nM Pol eta in columns 1, 2, and 5-48) were dispensed into a 1,536-well black solid-bottomed plate. Compounds (23 nL) were transferred via Kalypsys pin tool equipped with 1536-pin array. The plates were then incubated for 15 min at room temperature, and 1 muL substrate (50 nM final concentration) was added to start the reaction and kinetically read twice at 0 min and 10 min on the Viewlux reader

Compound Ranking:

1. Compounds are first classified as having full titration curves, partial modulation, partial curve (weaker actives), single point activity (at highest concentration only), or inactive. See data field "Curve Description". For this assay, apparent inhibitors are ranked higher than compounds that showed apparent activation.
2. For all inactive compounds, PUBCHEM_ACTIVITY_SCORE is 0. For all active compounds, a score range was given for each curve class type given above. Active compounds have PUBCHEM_ACTIVITY_SCORE between 40 and 100. Inconclusive compounds have PUBCHEM_ACTIVITY_SCORE between 1 and 39. Fit_LogAC50 was used for determining relative score and was scaled to each curve class' score range.

Grant Number: MH090825