Question

Explain how splicing factor Slu7 would control alternative splicing of mRNA precursor?

Answer 1

SLU7 controls SRSF1 and SRSF3 pre- mRnas splicings and prevent the induction of SRSF3 - TR forms. SRSF1 and SRSF3 differentiate the mRna alternative splicing. SLU7 participates in the second catalytic step of pre- mRna splicing , when the free hydroxyl group of exon attack the 3'- splice site to generate spliced mRNA.

Experiments recently shown that for other spliceosome factors, absence of SLU7 leads to formation of R- loops. As we know SLU7 regulates SRSF1 and then it regulates expression of SRSF3 to protection against R- loop formation. SLU7 induced in the incorporation of SRSF3 to generate SRSF3 2 isoforms in HCC cells. After evaluation of RNA clip assay we can say that SLU7 effect on SRSF3 was direct. By this way we can say that SLU7 is essential to maintain the correct alternative splicing of mRNA precursor.