hnRNP A1 and hnRNP H can collaborate to modulate 5′ splice site selection

Swapping domains in the hnRNP A1 and H proteins. (A) Representation of wild-type and chimeric proteins. (B) SDS-PAGE analysis of coomassie-blue stained purified proteins. (C) Binding of recombinant hnRNP H, F, Fs, Hs, FA1, and HA1 to ³²P-labeled HBS1 RNA was monitored by gel shift assay; 0, 0.5, and 1.22 μM of recombinant proteins were tested. (D) Western blot analysis after depletion of hnRNP F and hnRNP H. (E) Pre-mRNAs were incubated in a nuclear extract prepared from HeLa cells knocked down for hnRNP F/H expression and containing recombinant proteins (0.15 μM and 0.3 μM). Distal products (D), proximal products (P), and pre-mRNAs (Pre) are indicated.