Fig. 3 |. Upon fusion with CYCT1 HRD, CYCH promotes CDK7 hyperphosphorylation of Pol II CTD; DYRK1A also contains a functional HRD to target and hyperphosphorylate CTD.

a, b, e, The indicated anti-Flag immunoprecipitates (IP) were tested in kinase reactions as in Fig. 1a. c, The CYCT1 knockdown cells were co-transfected with HIV-1 LTR-luciferase reporter construct and plasmids expressing the indicated proteins. Luciferase activities were measured and analysed as in Fig. 1b. Data are mean ±s.d., n =3. d, Immobilized GST– CTD₅₂ was incubated with nuclear extract of HeLa cells expressing the indicated proteins. The bound proteins and 2.5% of input were analysed by western blotting. f, Nuclear extract of HeLa cells expressing the indicated proteins and anti-Flag immunoprecipitates from nuclear extract were analysed by western blotting. All western blots are representative of three independent experiments. For gel source data, see Supplementary Fig. 1.