Lecture 11: CSF Mutations & Cancer

Large scale DNA mutation F

Chromosomal rearrangements impacting genes

Small scale DNA mutation F

Minor alterations involving 1 or 2 nucleotides

Germ Line DNA mutation F

Mutations passed onto offspring

Local/Somatic DNA mutation F

Occurs during cell division, effects only local areas

Mutations can either causes substitution or Insertions/Deletions(Indels) - Both Functions =

Substitution - One nucleotide replaced by another

Insertions/Deletions (Indels) - May cause frameshift effecting downstream protein translation

Note: A 3-nucleotide change maintains the reading frame but can still alter the protein

Silent Mutation F

Doesn’t effect the amino acid sequence, no effect

Missense Mutation F

Contains a single nucleotide change that changes chosen amino acid, effects vary

Nonsense Mutation F

Results in a premature stop codon, resulting in truncated proteins

Frameshift Mutation F

Caused by insertion/deletions, changing the reading of amino acid sequence, potentially forming new proteins which can be functional or dysfunctional

Mitosis Checkpoints F

Ensure DNA is undamaged, cell size/supply is adequate, proper signals are present to continue cycling

M-phase Promoting Factor (MPF) at G2 checkpoint F

Cyclin-dependent kinase which regulates progression through G2 to mitosis. MPF phosphorylates proteins allowing mitosis to start.

Tumor Supressors F

Acts as brakes to suppress cell cycle progression

Proto-Oncogenes F

Acts as accelerators in stimulating cell cycle proliferation

Acquired Mutations

Mutations that arise in specific tissues (e.g UV damage, chemical exposure)

Inherited Mutations

Mutations present in cells, inherited from one or both parents