CBBM Lecture "Cyclin Dependent Kinase 5 (CDK5) Regulates the Circadian Clock" by

Prof. Dr. Urs Albrecht,

Department of Biology,

Unit of Biochemistry,

University of Fribourg,


will take place on Tuesday, June 18, 2019 from 17:15 to 18:15 hours in CBBM, Ground Floor, Seminar Room S1/S2.

Host: Prof. Dr. Henrik Oster

Institute of Neurobiology
University of Lübeck


Circadian oscillations emerge from transcriptional and post-translational feedback loops. An important step in generating rhythmicity is the translocation of clock components into the nucleus, which is regulated in many cases by kinases. In mammals, the kinase promoting the nuclear import of the key clock component Period 2 (PER2) is unknown. Here we show that the cyclin-dependent kinase 5 (CDK5) regulates the mammalian circadian clock via phosphorylation of PER2. Knock-down of Cdk5 in the suprachiasmatic nuclei (SCN), the main coordinator site of the mammalian circadian system, shortened the free-running period in mice. CDK5 phosphorylated PER2 at serine residue 394 (S394) in a diurnal fashion. This phosphorylation facilitated interaction with Cryptochrome 1 (CRY1) and nuclear entry of the PER2-CRY1 complex. Taken together, we found that CDK5 is the kinase that drives nuclear entry of PER2, which is critical for establishing an adequate circadian period of the molecular circadian cycle. Therefore, CDK5 is critically involved in the regulation of the circadian clock and may represent a link to various diseases affected by the circadian clock.


Urs Albrecht is Professor in the Biochemistry Unit at University of Fribourg in Switzerland. His research interest is focused on the the question how clocks in different tissues adjust to environmental cues and how the brain integrates this information to produce coherent systemic circadian rhythms as observed in food anticipation, drug seeking and metabolic rhythms. 

Prof. Albrecht holds degree in Biochemistry from University of Zurich and received his doctoral degree from University of Bern. After several years of postdoctoral training at Baylor College of Medicine in Houston, USA he was appointed Assistant Professor in the Department of Biochemistry at Baylor College. From 1999 to 2001 he was Assistant Professor in the Max Planck Institute of Experimental Endocrinology in Hannover, Germany. In 2001 he returned to Switzerland and took on the position of Assistant Professor in the Department of Biochemistry at University of Fribourg. Since 2018 he is Full Professor at the Department of Biology at University of Fribourg.