CK2β does not contribute to the inhibition of CLK degradation.

<p>(A, B) Western blot of nonsonicated head extracts from flies collected at DD1. Gray and black bars represent subjective day and subjective night, respectively. A CB stained band in the size range of CLK is used as a loading control. Brackets indicate hypo- and hyperphosphorylated forms of CLK. At least two independent experiments were performed for each blot. (A) Comparison between <i>tim > CkIIβ RNAi</i> (<i>w; tim-gal4/106845; 32377/+</i>) and <i>tim-gal4/+</i> controls in a <i>per⁺</i> background, for TIM, PER, and CLK proteins. (B) Comparison between <i>tim > CkIIβ RNAi</i> and <i>tim-gal4/+</i> controls in a <i>per⁰</i> background, for TIM and CLK. <i>a</i> and <i>b</i> are different protein extracts from the same genotype at the same time point. (C) Quantitative RT-PCR measurements of <i>Clk</i> mRNA levels in heads of flies collected at DD1. Results shown are means of pooled values from two time points (CT2 and 14, which gave similar values) with two independent samples for each time point. Error bars indicate s.e.m. Average values were normalized to the mean control (<i>per⁰ w</i>; <i>tim-gal4</i>/+) values set to 100. (D) CLK protein/<i>Clk</i> mRNA ratio calculated from mean CT2–CT14 values of Western blot (B) and quantitative RT-PCR (C) data. Ratios were normalized to the control (<i>per⁰ w</i>; <i>tim-gal4</i>/+) ratios set to 100.