Fig. 6. Nucleocytoplasmic compartmentalization of miRNA processing. (A) In vitro processing of miRNA in fractionated HeLa cell extract. The indicated amounts of the nuclear or cytoplasmic fraction were used for in vitro processing. The lower panel shows the ∼22 nt fragments after longer exposure. (B) Western blot analysis. Nucleoplasmic and cytoplasmic fractions were probed with anti-hnRNP C1/C2 antibody and anti-eIF4E antibody.