Table 3.

Validation of the most potent interactions identified in the in vitro binding assay at 10 μM (see Methods, Fig. 2, Supplementary Table 5) using an orthogonal assay that directly measures kinase catalytic activity using a widely-validated radiometric assay⁴⁰.

Kinase Group	Gene Name	Kinase complex and aliases	Niraparib	Rucaparib
CMGC	DYRK1B	—	82%	53%
CMGC	CDK16	CDK16/cyclin Y (PCTAIRE, PCTK1)	n.b.	82%
CAMK	PIM3	—	15%	78%
CMGC	DYRK1A	DYRK1	76%	49%
CMGC	HIPK1	—	40%	−16%
CAMK	MYLK4	—	19%	36%
Other	AURKB	Aurora B	34%	n.b.
CMGC	HIPK2	—	23%	−6%
CAMK	PIM1	—	22%	27%*
CMGC	CSNK2A1	CK2a	12%	21%
AGC	LATS2	—	17%	n.b.
CMGC	CSNK2A2	CK2a2	−1%	17%
AGC	CIT	STK21	10%	15%
Other	HASPIN	Haspin	10%	−6%
CMGC	CDK4	CDK4/cyclin D3	n.b.	10%
CMGC	HIPK3	—	5%	−12%
CAMK	TSSK3	STK22C	n.b.	−1%
PKL	PIK3C3	VPS34	−1%*	n.b.
CAMK	PIM2	—	−5%	n.b.
CAMK	STK17A	DRAK1	n.d.	−6%

The table displays the average of duplicate (n = 2) measurements of the percentage of enzyme inhibition relative to DMSO controls sorted by maximum percentage of inhibition. All assays were performed using 1 μM drug concentration and the appropriate Km concentration of ATP. From all the tested kinases, only 4 inhibit the enzyme by >50%. These four most potent interactions, expected to be submicromolar, are displayed at the top of the table and in bold. n.b. not binding. n.d. not determined due to low binding (Supplementary Table 5). * n = 1.