FIGURE 6:

LAS1L and NOL9 interact with the mammalian Rix1 complex on pre-60S ribosomal particles. Nuclear extracts from HCT116 cells were fractionated by centrifugation on a 10–30% sucrose gradient. Fractions were collected, and the optical density was measured at 260 nm (A₂₆₀). Based on the A₂₆₀ profile, fractions corresponding to free nuclear proteins (1, 2, and 3), pre-40S ribosomal particles (8, 9, and 10), and pre-60S ribosomal particles (12, 13, and 14) were then combined and immunoprecipitated (IP) with rabbit IgG (A) as a negative control or with PELP1 (B) or LAS1L (C) antibodies. Associated proteins were separated on SDS–PAGE and analyzed by Western blotting with specific antibodies (indicated on the left). WCL, whole-cell lysate; *, presence of an unspecific band; #, an IgG band.