Inhibition Assay: The ability of the nuclear factor-kappa B (NF-kB)-inducing kinase (NIK) to catalyze the hydrolysis of adenosine-5'-triphosphate (ATP) was monitored using the Transcreener ADP (adenosine-5'-diphosphate) assay (BellBrook Labs). Purified NIK (0.2-1 nM) derived from a baculovirus-infected insect cell expression system was incubated with test compounds for 1-3.5 hours in 50 mM 2-[4-(2-hydroxyethyl)piperazin-1-yl]ethanesulfonic acid buffer (pH 7.2) containing 10 mM MgCl.sub.2, 2 mM dithiothreitol, 10 uM ATP, 0.01% Triton X-100, 0.1% gamma-globulins from bovine blood, 1% dimethylsulfoxide (DMSO), 12 ug/mL ADP antibody and 4 nM ADP-AlexaFluor.RTM. 633 tracer. Reactions were quenched by the addition of 20 mM 2,2',2'',2'''-(ethane-1,2-diyldinitrilo)tetraacetic acid and 0.01% Brij 35. The tracer bound to the antibody was displaced by the ADP generated during the NIK reaction, which causes a decrease in fluorescence polarization that was measured by laser excitation.
Inhibition of TNF-alpha-stimulated RELA translocation from cytoplasm to nucleus in human HeLa cells preincubated for 4.5 hrs followed by TNF-alpha stimulation measured after 30 mins
Inhibition of NIK (unknown origin) expressed in HEK293 cells assessed as decrease in NFkappaB signal after 24 hrs by dual glo luciferase reporter gene assay
Inhibition of NIK in human HeLa cells assessed as decrease in antilymphotoxin-beta receptor antibody-stimulated p52 translocation from cytoplasm to nucleus after 5 hrs
Inhibition of N-terminal His6-tagged recombinant full-length human p110delta/untagged recombinant full length human p85alpha expressed in baculovirus infected Sf21 insect cells using PIP2:3PS lipid substrate after 120 mins by ADP-Glo assay