Abstract
The SF1 protein recognizes the introns 3' regions during early stages of the spliceosome formation, but it is not required to constitutive splicing of all pre-mRNA in cells. Thus, SF1 acts as an alternative splicing factor on a cellular subset of pre-mRNAs. Besides acting on splicing, other functions have been described for SF1 in RNA nuclear retention and transcriptional repression. In a…