BIO315H5 Lecture 8: BIO315 – Lecture 8
Document Summary
Important for cell to ensure that whatever protein is generated is correct. Only occurs on mrna that are not damaged. Translation only occurs on mrnas that have a proper 5" cap and poly a tail. Improper slicing introduces premature stop codons - results in much shorter/truncated proteins. When every correct splicing event occurs there is an ejc that is deposited. All the ejcs are removed prior to the first stop codon during the first round of translation called surveillance Past the normal stop codon there are no more ejcs - cell understands this as a successful round of surveillance. Translation stops at the first in-framed stop codon. Upf proteins interact with ejcs and in-framed stop codon - triggers degradation of mrna - improper slicing. Protein needs to fold properly to acquire final state. May bind to essential co-factor needed for its function. May have to bind to other protein subunits.
