Fig. 4.

The phosphatase activity of SJ1 is necessary to restore normal mEPSC amplitude in SJ1-KO mice. (A) Traces from SJ1-KO neuron expressing either WT SJ1–145 or a mutant SJ1–145 lacking both the Sac1 and the inositol 5-phosphatase activities (mtSJ1–145) demonstrate smaller mEPSC amplitudes in cells transfected with WT SJ1–145. (B and C) Statistical analysis of mEPSCs, showing reductions in mEPSC amplitude (B) and apparent frequency (C) in SJ-KO neurons expressing SJ1–145 relative to SJ1-KO neurons expressing mtSJ1–145.