Figure - PMC

Skip to main content

An official website of the United States government

Here's how you know

Here's how you know

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.

View full-text article in PMC

. 2020 Nov 26;11:612510. doi: 10.3389/fphys.2020.612510

Search in PMC
Search in PubMed
View in NLM Catalog
Add to search

Copyright © 2020 Brenna and Albrecht.

This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

PMC Copyright notice

Phosphoswitch model. PER2 regulates the speed of the circadian clock through the axis CDK5-CKI. When PER2 is phosphorylated by CDK5 it is stabilized and it goes into the nucleus. Under normal conditions, nuclear PER2 is phosphorylated by CKI ε/δ at Ser-477 which is followed by nucleus/cytoplasm shuttling and proteasomal degradation. However, following a switch on the temperature, PER2 can be phosphorylated at the FASP sites (pS659-662-665-668-671), which stabilizes the protein. As consequence, the clock is slowed down. Additionally, CDK5 and CKI can reciprocally regulate their activity, speeding up or slowing down the clock accordingly.