Linking hnRNP A1/A2 with P-TEFb.
A, Association of 7SK with P-TEFb. The association between 7SK snRNA and CDK9 was tested 72 hours post-transfection with the A1/A2 siRNAs, or 6 hours after treatment with DRB (100 μM). RNA immunoprecipitation (RNA-IP) with anti-CDK9 or without antibody as control were performed and the recovered RNA was quantitated by qRT-PCR with primers specific for 7SK. Data are presented as percent of input 7SK and are averages of 3 experiments with error bars representing SD. *: p<0.05, two tailed, two sample equal variance, Student’s t-test. B, Relative amount of 7SK RNA in extracts used for RNA-IP experiments quantified by qRT-PCR. The amounts were normalized for ACTB, B2M and mock treatment. C, The level of CDK9 in input samples was evaluated by immunublotting using an anti-CDK9 antibody and Ponceau staining of the membrane to show equivalent loading. The presence of a non-specific band reacting with the anti-CDK9 antibody is indicated by an asterisk (*).