FIG 1.

TcRNA Pol II is phosphorylated and tightly associated with chromatin. (A) Western blot of T. cruzi epimastigote pellets dissolved and boiled in SDS-PAGE sample buffer (Total) or previously lysed under nondenaturing conditions for the separation of chromatin (Chr) and soluble (Sol) fractions, before addition of sample buffer. The molecular mass of TcRNA Pol II is shown at left (kDa). (B) Western blot of parasite lysates (Total) or of the chromatin fraction treated without (−) or with (+) CIAP. (C) Western blots of total lysates of control cells (−) or cells pretreated (+) with 90 nM calyculin (2 h), 500 nM okadaic acid for the indicated times, or 500 μM DRB (3 h). The blots were probed with anti-TcRNA Pol II, anti-eIF5A, anti-histone H4, and anti-β-tubulin.