Catalyzes the phosphorylation of 1D-myo-inositol 1,4,5-trisphosphate (InsP3) into 1D-myo-inositol 1,3,4,5-tetrakisphosphate and participates to the regulation of calcium homeostasis. 1D-myo-inositol 1,4,5-trisphosphate + ATP = 1D-myo-inositol 1,3,4,5-tetrakisphosphate + ADP + H(+) IP3K is activated by calcium and calmodulin. Form B is much more sensitive to calcium/calmodulin than form A. Interacts with DMTN. Belongs to the inositol phosphokinase (IPK) family. Truncated N-terminus.