PAF1 is regulated by CNOT4 at the protein level.

<p>(A, B) The levels of endogenous PAF1 protein in CNOT4-overexpressing or silenced whole-cell lysates were analyzed by immunoblot. The silencing efficiency of CNOT4 was measured by RT-PCR (B). (C) The PAF1 and CNOT4 protein levels were measured in cells transfected with different siRNAs. (D) HEK293 cells were transfected with control or CNOT4 siRNA specific to the UTR, along with CNOT4 expression vectors. The protein levels of endogenous PAF1, endogenous CNOT4 and overexpressed V5-CNOT4 were measured by immunoblot assay. (E) After CNOT4 siRNA was transfected into HEK293 cells, PAF1 and CNOT4 mRNA levels were measured by conventional PCR (left) and quantitative real-time PCR (right). The protein levels of endogenous PAF1 were detected by immunoblot assay (left, bottom).