Molecule alters circadian clock via light trigger

Abstract

A light-activated molecule can reversibly shift the length of the circadian clock’s cycle in living cells and tissues ( Nat. Commun. 2021, DOI: 10.1038/s41467-021-23301-x ). The tool provides a targeted, noninvasive way to study how the clock affects cellular physiology, says Ben Feringa , a chemist at the University of Groningen who co-led the work. The clock, a signaling system that is found in nearly all organisms, keeps cells’ functions tied to a daily cycle. The team used an azobenzene moiety, which changes conformation from the stable trans isomer to the less stable cis isomer when exposed to light. The cis isomer gradually reverts to trans on its own, or it can be converted photochemically. The researchers added an azobenzene switch to a molecule called longdaysin. Longdaysin slows the clock by interfering with the action of a key regulator of the circadian clock. Violet light (400 nm) activates longdaysin in