The multiple facets of Per2

Abstract

The Period 2 (Per2) gene is an important component of the circadian system. It appears to be not only part of the core oscillator mechanism, but also part of the input and output pathways of the clock. Because of its involvement at multiple levels of the circadian system, Per2 needs to meet a variety of different demands. We discuss how Per2 might be able to fulfill multiple functions by reviewing known facts and combine this with speculations based on these facts. This might provide new views about Per2 function and help to better understand diseases that are rooted in the circadian system.