FIG. 7.

“Cross talk” between hnRNP A1 molecules bound at distant sites. (A) Sequences of synthetic RNA transcripts for UV cross-linking experiments. The radiolabeled cytidines are indicated in bold italic. The underlined hexanucleotide is a high-affinity hnRNP A1 binding site (ESS). (B) UV cross-linking with 8 nM RNA transcripts from panel A and WT control from Fig. 1A, in the presence of increasing recombinant hnRNP A1 (0.03 to 0.2 μM). Detection and quantitation of the cross-linked products were as for Fig. 1B. The position of the ESS in each of the RNAs is indicated by a dark line. (C) Sequences of synthetic RNA transcripts for UV cross-linking experiments. The radiolabeled cytidines are indicated in bold italic. The underlined hexanucleotide is a high-affinity hnRNP A1 binding site: UAGGGU is the WT version, and UUGGGU is the inactive, mutant version, with the mutated nucleotide shown in italic. (D) UV cross-linking with 16 nM RNA transcripts from panel C and the XT3 control from panel A, in the presence of increasing recombinant hnRNP A1 (0.05 to 0.4 μM). Detection and quantitation of the cross-linked products were as for Fig. 1B. The position of the ESS in each of the RNAs is indicated by a dark line; a mutant ESS is indicated by an asterisk.