BCH 3170 Lecture Notes - Lecture 20: Exon Junction Complex, Zbp1, Exosome Complex
Document Summary
Nonsense mutation leads to a premature stop codon. Normal splicing results in getting rid of the introns and you get your mature mrna. Exon junction complex are located at the exon-exon boundary. First thing that happens is that one ribosome comes and checks it out, does a test run, if everything is good then you get translation (on good mrna) But when you get abnormal splicing, you get an intron that is kept and you almost immediately reach a stop codon inframed in intron one. Upf will in turn attract the exosome complex, and that will result in degradation. Cbc (cap binding complex) will be removed and replaced by the eukaryote initiation factor for g (?) mrna cellular distribution. Mrnas directed active transport , requires functional cytoskeleton and motor proteins some mrnas get into the cytoplasm and diffuse randomly, and at one point will find a protein that will anchor them somewhere (eg. corner of a cell)