Paprotrain

Paprotrain is a cell-permeable inhibitor of the kinesin MKLP-2, inhibits the ATPase activity of MKLP-2 with an IC₅₀ of 1.35 μM and a K_i of 3.36 μM and shows a moderate inhibition activity on DYRK1A with an IC₅₀ of 5.5 μM. IC50 & Target: IC50: 1.35 μM (MKLP-2)^[4], 5.5 μM (DYRK1A)^[1]
Ki: 3.36 μM (MKLP-2)^[4] In Vitro: Paprotrain has been screened on a panel of CNS kinases. While inactive (IC₅₀ >10 μM) on CDK5 and GSK3, it has shown a moderate activity on DYRK1A (IC₅₀=5.5 μM)^[1]. Time-lapse microscopy shows that disrupting MKlp2 expression with paprotrain results in polar body extrusion failure. This could be rescued after rescuing oocytes from paprotrain in fresh medium. Cell cycle analysis shows that most oocytes are arrested at metaphase I or telophase I. However, oocyte spindle structure and chromosome alignment are not disrupted after the inhibition of MKlp2 by paprotrain^[2]. Paprotrain-treated porcine oocytes suffer failure of nuclear maturation. The number of oocytes arrested at early MI stage increase in a dose-dependent manner after KIF20A activity inhibition, while the percentage of oocytes that reach ATI and MII stages decrease after treatment^[3].