LIFESCI 3 Lecture Notes - Lecture 17: Alternative Splicing, Electrophile, Small Nuclear Rna
Document Summary
The poly a signal sequence is a cis element located at the end of the coding regions of ek genes. When transcribed into mrna, it serves as a binding site for both rna cleavage factors and poly a polymerase. Cleavage factors & poly a polymerase (pap) are factors recruited for serine 2 phosphorylation. Stay on rna pol tail, wait for poly a signal to be transcribed. Exonuclease looks for uncapped rna exiting pol. It cleaves uncapped rna; does so faster than rna being synthesized, so catches up to rna pol (cid:862)torpedo (cid:373)odel(cid:863) Bumps into rna pol -> transcription termination. Rho dependent termination (helicase based: ek cells: exonuclease based termination. Splicing (occurs during transcription: mrna is shorter than the dna coding for it because introns are removed (splicing, exons are the sequences that remain in the mrna, splicing does(cid:374)"t ha(cid:448)e to o(cid:272)(cid:272)ur (cid:271)efore cleavage, clicker question: pulse-chase experiment. Heteronuclear rna = hnrna = rna with a wide.
