Mouse Cryptochrome

Updated: 2026-07-22

Overview

Mouse Cryptochrome (mCRY) refers to a family of flavoprotein photoreceptors (mCRY1 and mCRY2) that play crucial roles in circadian rhythm regulation. These proteins are homologs of plant photolyases but lack DNA repair activity in mammals. They function as core components of the negative feedback loop in the mammalian circadian clock. Discovered in the late 1990s, mouse cryptochromes have become essential research tools for understanding biological timing mechanisms. Their ability to sense blue light and interact with clock proteins makes them valuable for studying sleep disorders, metabolic regulation, and seasonal adaptation in mammals.

Physical and Chemical Properties

Mouse cryptochromes are soluble proteins with molecular weights around 70-75 kDa, depending on the isoform (mCRY1 or mCRY2). They contain flavin adenine dinucleotide (FAD) as a chromophore, which enables their light-sensing capability. The proteins exhibit maximum absorption in the blue-light spectrum (≈450 nm). Structurally, mCRY proteins consist of two domains: an N-terminal photolyase homology region (PHR) and a C-terminal extension unique to cryptochromes. The PHR domain binds FAD and mediates light-dependent conformational changes, while the C-terminal region is involved in protein-protein interactions critical for circadian clock function.

Main Applications

In research settings, mouse cryptochromes are primarily used to investigate circadian biology mechanisms. They serve as molecular tools in: (1) Circadian clock disruption studies using knockout mouse models, (2) Protein-protein interaction analyses with PERIOD proteins and other clock components, and (3) Photoreception studies examining non-visual light responses. Pharmaceutical applications include target identification for circadian rhythm-related disorders and chronotherapy development. The proteins are also valuable in biotechnological applications involving optogenetic systems, where light-sensitive protein domains are engineered for precise cellular control.

Safety and Storage

Mouse cryptochrome proteins require careful handling to maintain stability and activity. Store lyophilized powders at -20°C or below, protected from moisture. Reconstituted proteins should be aliquoted to avoid repeated freeze-thaw cycles and stored at -80°C for long-term preservation. While not classified as hazardous, standard laboratory safety protocols should be followed. Use personal protective equipment when handling, especially if working with recombinant proteins expressed in bacterial systems. Avoid exposure to bright light during experiments, as this may affect protein functionality.

B2B Procurement Guide

When procuring mouse cryptochrome proteins, prioritize suppliers specializing in circadian biology reagents. Key specifications to verify include: protein purity (≥95% by SDS-PAGE), endotoxin levels (<1 EU/μg), and functional activity (verified by binding assays). Consider the expression system - E. coli-expressed proteins are most common but may lack post-translational modifications. For certain applications, mammalian cell-expressed variants may be preferable. Request detailed storage buffers and formulation information, as these significantly impact protein stability and experimental outcomes.