The hnRNPs F and H2 bind to similar sequences to influence gene expression

摘要: The hnRNPs (heterogeneous nuclear ribonucleoproteins) F and H2 share a similar protein structure. Both have been implicated as regulating polyadenylation, but hnRNP had positive effect, whereas acted negatively. We therefore carried out side-by-side comparisons of their RNA-binding in vivo actions. binding the CstF2 (64 kDa cleavage stimulatory factor) to SV40 (simian virus 40) late pre-mRNA substrates containing downstream GRS (guanine-rich sequence) was reduced by F, not H2, UV-cross-linking assay. Point mutations 14-nt influenced purified or parallel. Co-operative individual proteins RNA lost with G1−5 G12−14 regions; both regions seem be necessary for optimal interactions. Using reporter green fluorescent assay inserted poly(A) (polyadenine) signal, expression diminished mutant sequence which decreased (SAA20) enhanced 12–14-nt that showed (SAA10). small interfering RNA, down-regulation levels expression, confirming confers influence; contrast, decreasing negligible influence on intact GRS. A pronounced diminution seen SAA20 both. Thus relative cells, well target sequences pre-mRNA, gene expression.