SPHINX31

SPHINX31 is a potent inhibitor of serine/arginine-rich protein kinase 1 (SRPK1) IC₅₀ = 5.9 nM). It displays selectivity for SRPK1 over a panel of 50 kinases at a concentration of 1 μM. SPHINX31 inhibits phosphorylation of serine/arginine-rich splicing factor 1 (SRSF1), an SRPK1 substrate, in PC3 cells (EC50 = 360 nM) and increases expression of the anti-angiogenic VEGF-A165b splice variant in retinal pigment epithelial (RPE) cells.