I(1,3,4,5)P4 is dephosphorylated to I(1,4,5)P3 by MINPP1 in the ER lumen

In the endoplasmic reticulum (ER) lumen, multiple inositol polyphosphate phosphatase 1 (MINPP1) dephosphorylates inositol 1,3,4,5-tetrakisphosphate (I(1,3,4,5)P4) to inositol 1,4,5-trisphosphate (I(1,4,5)P3) (Caffrey et al. 1999, Chi et al. 1999).

在内质网腔室中，多种肌醇多磷酸磷酸酶1（MINPP1）将肌醇1,3,4,5-四磷酸（I(1,3,4,5)P4）去磷酸化为肌醇1,4,5-三磷酸（I(1,4,5)P3)（Caffrey等，1999年，Chi等，1999年）。