Kinase experiment:

XMU-MP-1 is dissolved in DMSO (stock concentration, 10 mM). For the in vitro kinase inhibition assays, recombinant GST-tagged MOB1a and various forms of recombinant His-tagged full-length MST1 or MST2 kinase are expressed and purified from Escherichia coli. The assays are performed with the various doses of XMU-MP-1 in the kinase assay buffer for 30 min at 30℃[1].

• Placenta (2022). PMID:36103800

XMU-MP-1 is a reversible, potent and selective inhibitor of MST1/2 with IC50 values of 71.1 ± 12.9 nM and 38.1 ± 6.9 nM, respectively [1].

The Sterile 20-like kinases MST1 and MST2 are key components of the Hippo signaling cascade that play an important role in tissue regeneration, stem cell self-renewal and organ size control [1].

XMU-MP-1 is a potent, selective and ATP-competitive MST1/2 inhibitor. In ELISA-based high-throughput screening assay, XMU-MP-1 at 10 μM inhibited MST2 kinase activity by more than 50% and dose-dependently inhibited the phosphorylation of MOB1 mediated by MST2. In human liver carcinoma (HepG2) cells, XMU-MP-1 (0.1 to 10 μM) dose-dependently reduced the phosphorylation of endogenous MOB1, LATS1/2, and YAP. Also, in a variety of cell lines, including human osteosarcoma (U2OS), human colorectal adenocarcinoma (SW480) and human pleomorphic hepatocellular carcinoma (SNU-423), XMU-MP-1 inhibited H2O2-stimulated MOB1 phosphorylation and MST1/2 autophosphorylation [1].

In wild-type mice, treatment with XMU-MP-1 once a day before a two-thirds partial hepatectomy followed by daily treatment for 7 days. XMU-MP-1 significantly reduced the phosphorylation levels of MOB1 and YAP. After partial hepatectomy, XMU-MP-1 substantially increased liver regeneration. In CCl4-induced liver chronic injury mice treatment with XMU-MP-1 (1 mg/kg) had a small amount of collagen deposition, suggesting XMU-MP-1 is capable of partially rescuing fibrosis [1].

Reference:
1. Fuqin Fan, Zhixiang He, Lu-Lu Kong, et al. Pharmacological targeting of kinases MST1 and MST2 augments tissue repair and regeneration. Science Translational Medicine 17 Aug 2016: Vol. 8, Issue 352, pp. 352ra108.