Cryptocrome Activator, KL001

A cell-permeable carbazole compound that competes against FAD (flavin adenine dinucleotide) for cryptocrome (CRY) 1 & 2 binding, displaying little affinity toward other clock proteins (PER1/2, CLOCK, or BMAL1) or inhibitory activity against casein kinase (CKIα, CKIδ, and CK2) activity even at concentrations as high as 100 µM. Shown to selectively stabilize cellular CRY1/2 protein, but not mRNA, by preventing FBXL3-mediated CRY1/2 ubiquitination and proteasomal degradation, effectively lengthening the period and reducing the amplitude of the circadian transcription rhythms of Bmal1 and Per2 promoter-mediated transcription activity (IC₅₀ of intensity reduction = 14 and 0.82 µM, respectively, in U2OS reporter assay). KL001 is also reported to block glucagon-induced Pck1 and G6pc mRNA upregulation as well as glucose production in primary murine hepatocyte cultures (IC₅₀<8 µM). Longdaysin (Cat. No. 438075), in comparison, exerts its circadian perturbation activity via casein kinase inhibition.

Cell permeable: yes

Primary Target
Cryptocrome protein

Reversible: yes

Packaged under inert gas

Following reconstitution, aliquot and freeze (-20°C). Stock solutions are stable for up to 6 months at -20°C.

Hirota, T., et al. 2012. Science337, 1094.

CALBIOCHEM is a registered trademark of Merck KGaA, Darmstadt, Germany

Toxicity: Standard Handling (A)