BIO 1140 Lecture Notes - Lecture 6: Rna Splicing, Guide Rna, Alternative Splicing
13 Mar 2017
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Rna is spliced in 2 diff alternative ways to produce. Dark blue = exons retained, light blue = possible exon included in only one of the mrnas, red lines = where introns (yellow) are removed: neg. control = repressor proteins binds, prevents removing of intron. = unable to remove without assistance from activator protein. The poly-a tails are gradually shortened by an exonuclease that chews away the tail in the 3 to 5 direction. Once a critical threshold of tail shortening has been reached, the 5 cap is removed (a process called. Rate of this process differs from each species of mrna. Any factors that affect the translation efficiency of an mrna will tend to have the opposite effect on its degradation: 2nd way = mrna is degraded begins with the action of specific endonucleases. Endonucleases cleave the poly-a tail from the rest of mrna in one steo.
