Description
K252a is a staurosporine analog isolated from Nocardiopsis sp. soil fungi that inhibits protein kinase (PK) C, PKA, Ca2+/calmodulin-dependent kinase type II, and phosphorylase kinase with IC50 values of 470, 140, 270, and 1.7 nM, respectively. Because it inhibits neurotrophin receptor tyrosine kinases, K252a at 100-500 nM has been used to suppress trophoblast proliferation and increase apoptosis associated with the disruption of mitochondrial functions in cultured choriocarcinoma cells. Recently, K252a has been shown to inhibit PRK1 (IC50 = 3.2 nM in vitro), a PKC-related kinase that phosphorylates histone H3 at threonine 11 and is involved in androgen-dependent gene expression.
Uses
K-252a is used to inhibit protein kinases involved in cell signaling processes, including CaM kinase; phosphorylase kinase, serine/threonine kinases, Trk. It is used to inhibit the actions of nerve growth factor (NGF) on PC1 2 cells and to inhibit smooth muscle myosin light chain kinase .
Definition
ChEBI: A organic heterooctacyclic compound that is a potent inhibitor of protein kinase C and is isolated from Nocardiopsis sp K-252a
Biological Activity
Non-selective protein kinase inhibitor; analog of staurosporine. Inhibits PKC (IC 50 = 32.9 nM), Ca 2+ /calmodulin-stimulated phosphodiesterases (IC 50 = 1.3-2.9 μ M), MLCK (K i = 20 nM) and receptor tyrosine kinases. Inhibits the oncogenic properties of MET; prevents autophosphorylation and activation of downstream effectors (MAPK, Akt).
Biochem/physiol Actions
Potent inhibitor of various protein kinases including protein kinase A, C, and G. It is is reported to selectively inhibit the actions of nerve growth factor (NGF) on PC1 2 cells and has been shown to inhibit smooth muscle myosin light chain kinase .
References
1) Kase et al. (1987), K-252 compounds, novel and potent inhibitors of protein kinase C and cyclic nucleotide-dependent protein kinases; Biochem. Biophys. Res. Commun., 142 436
2) Hashimoto et al. (1991), Potent and preferential inhibition of Ca2+/calmodulin-dependent protein kinase II by K252a and its derivative KT5926; Biochem. Biophys. Res. Commun., 181 423
3) Berg et al. (1992), K-252a inhibits nerve growth factor-induced trk proto-ooncogene tyrosine phosphorylation and kinase activity; J. Biol. Chem., 267 13
4) Ruegg et al. (1989), Staurosporine, K-252 and UCN-01: potent but non-specific inhibitors of protein kinases; Trends Pharmacol. Sci., 10 218
5) Mohri et al. (1999), K252a induces cell cycle arrest and apoptosis by inhibiting Cdc2 and Cdc25c; Cancer Invest., 17 391
