Fig. 6.

Expression of an Rbm3 fusion protein alters the abundance of a miRNA-containing complex. (A) RNA was extracted from fractions of a sucrose gradient profile of control cells at 32°C and stained with ethidium bromide. Lane 1 is RNA from the top of the gradient, and lane 2 is RNA from the complex that sediments between the top of the gradient and 40S subunits (indicated with an asterisk in Fig. 2 A). The positions of RNA size markers are indicated. (B) RNAs from fractions of a sucrose gradient profile of control cells at 32°C were phosphatase treated, [γ-³²P]ATP end-labeled, and separated in acrylamide–urea gels. RNAs in lanes 1–5 are from sequential fractions from the top of the gradient to the bottom. Lane 2 corresponds to the fraction represented in A, lane 2. (C) Northern blot analysis of fractions containing small RNAs from control (C) and c-Myc-Rbm3 (Rbm3) cells grown at 32°C by using a microRNA (mmu-miR-125b) probe. (D) Northern blot analysis of total RNA from control (C) and c-Myc-Rbm3 (Rbm3) cells grown at 32 or 37°C by using the mmu-miR-125b probe. The hybridization signals for C and D correspond to RNAs between the 20- and 30-nt size markers.