Reactome: A Curated Pathway Database

I(1,3,4,5)P4 is dephosphorylated to I(1,3,4)P3 by INPP5[3]/ITPK1 in the cytosol (R-HSA-1855218) [Homo sapiens]


A group of inositol phosphatases and the broad specificity enzyme inositol-tetrakisphosphate 1-kinase (ITPK1) dephosphorylate inositol 1,3,4,5-tetrakisphosphate (I(1,3,4,5)P4) to inositol 1,3,4-trisphosphate (I(1,3,4)P3). The group of inositol phosphatases involved are: inositol polyphosphate 5-phosphatase OCRL-1 (OCRL), phosphatidylinositol-3,4,5-trisphosphate 5-phosphatase 1 (INPP5D) aka SHIP1, phosphatidylinositol-3,4,5-trisphosphate 5-phosphatase 2 (INPPL1) aka SHIP2, phosphatidylinositol 4,5-bisphosphate 5-phosphatase A (INPP5J) aka PIPP, and synaptic inositol-1,4,5-trisphosphate 5-phosphatase 1 (SYNJ1).

The following lists the above proteins with their corresponding literature references: OCRL (Chang et al. 2002, Zhang et al. 1995, Zhang et al. 1998, Schmid et al. 2004); INPP5D (Drayer et al. 1996, Kavanaugh et al. 1996); INPPL1 (Chi et al. 2004); INPP5J (Mochizuki & Thompson 1999); SYNJ1 (Schmid et al. 2004); ITPK1 (Ho et al. 2002).

Additional Information
Compartment cytosol
Components of this entry
Input entries
Output entries
Catalyst Activity
PhysicalEntity Activity Active Units
INPP5(3)/ITPK1 inositol-1,3,4,5-tetrakisphosphate 5-phosphatase activity (0052659)  
Inferred Entries
Orthologous events