Fig. 4. Purified coilin degrades scaRNA 2 and 9 in vitro.

(A) Coilin and GST, purified to homogeneity, were subjected to SDS-PAGE and the gel was Coomassie stained. (B–D) RNA degradation assays using purified coilin or GST, shown in panel A, with 100 nM in vitro transcribed scaRNA 2 (B), scaRNA 9 (C) or scaRNA 9 containing an extended 3′-end (D). RNAs were incubated without protein (0) or with increasing amounts (approximately 0.2 µg, 0.5 µg and 0.7 µg) of GST or coilin. Reactions were then subjected to agarose gel electrophoresis and ethidium bromide staining. The arrowheads in panels B and D demarcate the full-length scaRNA based on expected size.