p90 is a sequence specific RNA-binding protein. A Restriction map of c-mos 3'UTR. Numbering is from the stop codon which is indicated by a star (*), EDEN represents the EDEN sequence present in the 3'UTR of c-mos. B and C Mapping of the binding sites of p90 in the c-mos 3'UTR. 32P-CTP (panel B: lanes 2–7) and 32P-GTP (panel B: lanes 8–11 and panel C: lanes 2–7) labeled transcripts, that correspond to different regions of the c-mos 3'UTR, were synthesised and used in UV crosslinking analyses as described in the legend to Figure 1. The portions of the c-mos 3'UTR cDNA used as template to synthesise the different RNAs is indicated above the lanes. The positions of p90 and EDEN-BP are indicated on the right of the panels and the sizes of the molecular weight markers (lane 1) are indicated on the left.