BIOLOGY 2C03 Lecture Notes - Intron, Oncogene, Tumor Suppressor Gene
Document Summary
Lecture 1 micrornas (mirnas) and the control of translation (march 21) sirna vs mirna. Small interfering rnas (sirnas) and micrornas (mirnas) are short rna species characterized by extensive region of secondary structure. They are generated by their own machinery but several factors and processes are common in the biosynthesis of these non-coding rna species sirnas function in genome surveillance limiting the propagation of viruses or transposons and controlling chromatin structure. Mirrnas are regulatory molecules limiting gene expression through diverse mechanisms including the inhibition of translation in animal cells. Translation initiation in eukaryotes: no shine-delgarno sequence on mrna. Initiation generally depends on the cap: the cap is recognized by elf4e. Several eif are required for initiation eif = eukaryotic initiation factor. Interaction of the polya binding protein at the 3" end of the mrna enhances the recruitment of the small ribosomal subunit. Functions of the cap: mrna stability, coupling to splicing, mrna export, mrna translation.
