Analysis of ChIP-enriched sites showed that most RNA binding protein sites are unique to ALY, PTBP1, or CSTF2. Additionally, many RNA binding protein sites overlapped with RNA Pol II and this is consistent with protein complex association between RNA binding proteins and RNA Pol II. (A) Overlap analysis of RNA binding proteins within the RefSeq-annotated regions. Numbers in each set indicate the number of enrichment sites that fell into that overlap category. (B) Overlap analysis of ALY, PTBP1, CSTF2, Pol II, and Pol IIa within RefSeq-annotated regions. (C) RNA binding proteins associated with one another as well as with RNA polymerase II. α-ALY (lane 2), α-PTBP1 (lane 3), α-CSTF2 (lane 4), and α-RNA polymerase II (lane 5 is 4H8, and lane 6 is 8WG16) antibodies were used to immunoprecipitate complexes from HeLa cell lysates. Mock IPs lacked primary antibody (lane 1).
