MCB 10 Lecture Notes - Lecture 14: P53, Tumor Suppressor Gene, Fusion Protein
25 Sep 2016
School
Department
Course
Professor
Document Summary
Lecture 14 cancer genetics: point mutations and splice site mutations. Creates truncated proteins that are often non-functional: a stop codon that is changed to a coding codon lengthens the protein. Splice site mutations alters a site where an intron is normally removed from mrna. This can affect the phenotype if: exon is skipped; ex: familial dysautonomia (fd) Intron is translated or exon is skipped; ex: cystic fibrosis (cf) mutation: deletions and insertions, frameshift mutations. Pseudogenes a dna sequence similar to a gene but is not translated (may not even be transcribed: crossing over between a pseudogene and a functional gene can disrupt gene expression. Pseudogenes may have evolved from the original gene by duplication and acquired mutation: expanding repeats insertion of triplet repeats leads to extra amino acids. Some genes are particularly prone to expansion of repeats. In the consequent generations, there are more copies of repeats. Loss of coordination and certain reflexes,, spine curvature, knee and ankle jerks.
