UCN-02 is a derivative of staurosporine and a stereoisomer of UCN-01, which has been first isolated from a high staurosporine-producing Streptomyces culture as a minor co-metabolite [1]. UCN-02 is protein kinase C inhibitor [1].
Protein kinase C (PKC), which can phosphorylate serine and threonine, is a family of protein kinase enzymes involved in regulating the function of other proteins. Protein kinase C plays an important role in several signal transduction cascades. Protein kinase C has been implicated in modulating membrane structure events, mediating immune responses, regulating transcription, learning and memory, and regulating cell growth [2].
UCN-02 inhibited protein kinase C with a slightly reduced potency than UCN-01. The IC50 values were 62 and 4.1 nM for UNC-02 and UCN-01, respectively. UCN-02 was cytotoxic to the growth of HeLa S3 cells.
References:
[1] Takahashi, I. ,Saitoh, Y.,Yoshida, M., et al. UCN-01 and UCN-02, new selective inhibitors of protein kinase C. II. Purification, physico-chemical properties, structural determination and biological activities. J.Antibiot.(Tokyo) 42(4), 571-576 (1989).
[2] Newton A C. Protein kinase C: structure, function, and regulation[J]. Journal of Biological Chemistry, 1995, 270(48): 28495-28498.