Relative abundance was calculated with respect to spliceosomal RNA (snRNA-U6) levels by real-time PCR. A) Levels of the indicated RNA in HeLa cells stably expressing Myc-tagged GRIM-1 isoforms. GRIM-1 isoforms differentially suppress box H/ACA-containing RNA. Top: snoRNA-73 (open), -74 (hatched), -50 (light gray); Middle: scaRNA-8 (stippled), -13 (brick), TERC (black); Bottom: spliceosomal RNA (snRNA-U2 (wavy)) and box C/D-containing RNA (snoRNA-U3 (checkered)) levels. A related box C/D snoRNA-U13 (dark gray) levels are not influenced by GRIM-1. B) Levels of the indicated RNA upon GRIM-1 depletion in HeLa cells. GRIM-1-depleted cells (GS) show increased box H/ACA-containing RNA. Top: snoRNA-73, -74 and -50; Middle: scaRNA-8, -13, TERC; Bottom: snRNA-U2 and snoRNA-U3 levels. A related box C/D snoRNA-U13 levels is not influenced by GRIM-1. Bar patterns same as in (A). **, p<0.01.