Animation:
PER protein in normal vs. early wake sleep patterns

The Molecular Biology Review module included an animation of PER gene transcription and translation from a biointeractive tutorial by the Howard Hughes Medical Institute (HHMI) on Biological Clocks: The Drosophila Molecular Model.

Let's revisit the molecular model of biological clocks, but this time in mammals. View the mammalian animation (part 4) that shows the difference in PER protein degradation between individuals with normal sleep patterns versus patients with disturbed (early wake) sleep patterns.

The hPER2 sequence is mutated, so that the proteins in the lower half of the animation ("Mutant") are not degraded by the enzyme (shown by triangle). hPER2 accumulates faster in the mutant, and turns off the cycle sooner. Thus, the patients with a mutant sequence have a shorter sleep cycle, and wake up sooner than other people.