BIOL 300 Lecture Notes - Upf1, Start Codon, Terminal And Nonterminal Symbols

• School: McGill University
• Department: Biology (Sci)
• Course: BIOL 300
• Professor: Siegfried Hekimi

Document Summary

Normally, a pre-mrna has a 5" urt, a start codon, stop codons, and a 3" utr. In a normal transcript, the stop codon would be located in the last exon (which is normally large because of the length of the 3" utr) This diagram can be separated into two halves; the top right section represents vertebrates and the lower- left section is for invertebrates. While they are slightly different, they share many important similarities, including the use of proteins called upf1, 2 and 3 (some of which form part of the ejc) In the nucleus, the mrna is spliced and the ejc is formed, containing many proteins, including. Upf3, which is important for nmd: the mrna is exported at which point the ribosome begins to translate. When the ribosome encounters the stop codon in a non-terminal exon, it will stall at close proximity to the ejc, allowing the two components to interact.