More About Mismatch Repair
During DNA replication mistakes can occur as DNA polymerase copies the two strands. The wrong nucleotide can be incorporated into one of the strands causing a mismatch. Normally there should be an "A" opposite a "T" and "G" opposite a "C". If a "G" is mistakenly paired with a "T", this is a potential mutation. Fortunately cells have repair mechanisms. In this case repair proteins called PMS2, MLH1, MSH6, and MSH2, help recruit an enzyme called EXO1 that chops out a segment of the mutant strand. Then a DNA polymerase can replace the missing section of the strand with a new section and the mistake is repaired.
Mismatch Repair Background
Knowing the genetic path that a particular cancer follows could someday help physicians better treat individual patients. By determining the genetic defects responsible for a specific cancer, physicians might be able to select the therapy that will be most effective at eliminating that cancer. Furthermore, each cancer-causing gene that researchers identify can serve as a target for the development of more specific therapies that will wipe out cancer cells while leaving healthy cells unharmed.
From lecture one of the 2003 Holiday Lectures Series "Learning From Patients: The Science of Medicine."
Mismatch Repair Teaching Tips
The animations in this section have a wide variety of classroom applications. Use the tips below to get started but look for more specific teaching tips in the near future. Please tell us how you are using the animations in your classroom by sending e-mail to firstname.lastname@example.org.
The 2003 Holiday Lectures Series "Learning From Patients: The Science of Medicine."
Mismatch Repair Credits
Director: Dennis Liu, Ph.D.
Scientific Direction: Bert Vogelstein, M.D.
Scientific Content: Satoshi Amagai, Ph.D.
Animator: Chris Vargas