FIG. 3.

Coimmunoprecipitation of snRNA with tagged-CUS2. Extracts prepared from strains carrying untagged (lanes 1 to 4) or tagged (lanes 5 to 8) CUS2 protein were incubated with anti-HA antibody 12CA5 bound to PAS and washed with NET buffer containing 50 mM (lanes 1 and 5), 100 mM (lanes 2 and 6), 150 mM (lanes 3 and 7), and 200 mM (lanes 4 and 8) NaCl. RNA was extracted from the immunoprecipitate and used as the template for a reverse transcription reaction using a mixture of 5′-end-labeled oligonucleotides complementary to U1, U2, U5, and U6 snRNAs. The right-hand lane is a sample from a reverse transcription reaction using total yeast RNA as the template.