calyculin a

Calyculin A is a highly potent and cell-permeable inhibitor of protein phosphatases 1 (PP1) and 2A (PP2A), isolated from the marine sponge Discodermia calyx. It acts at nanomolar concentrations (IC50 for PP1 ≈ 2 nM; IC50 for PP2A ≈ 0.5–1 nM) and is widely used in biological research to study phosphorylation-dependent signaling pathways[2][3][5]. Mechanistically, it binds to the catalytic subunits of serine/threonine protein phosphatases PP1 and PP2A, inhibiting their activity and thereby increasing cellular phosphorylation levels[3][10]. Calyculin A is also recognized as a potent tumor promoter in experimental models due to its ability to induce hyperphosphorylation of proteins involved in cell growth regulation[10]. It is not approved for clinical use or marketed as a pharmaceutical drug; its applications are strictly limited to laboratory research.

Other names

Calyculin A(-)-Calyculin Acalyculin a from discodermia calyxC05370C-05370C 05370