SMIP-30 is a potent and selective inhibitor of PPM1A with IC50 of 1 uM, selectively inhibits the phosphatase activity of PPM1A.SMIP-30 shows poor inhibitory activity against closest homolog PPM1B (IC50>30 uM).SMIP-30 is an uncompetitive inhibitor for PPM1A (Ki=0.84 uM), does not exhibit any cytotoxic effects up to 30 uM in THP-1 macrophages.SMIP-30 dose-dependently reduces the Mtb burden in infected macrophages, and is well tolerated in vivo and combined with rifampicin reduces Mtb burden in the lungs of infected mice.SMIP-30 induces LC3B-II expression, activates autophagy in Mtb-infected macrophages in a PPM1A-dependent manner.SMIP-30 induces a dose-dependent increase in phosphorylation of S403-p62 in WT macrophages.
