GO:0000827:   inositol-1,3,4,5,6-pentakisphosphate kinase activity
Catalysis of the reaction: ATP + 1D-myo-inositol 1,3,4,5,6-pentakisphosphate = ADP + diphospho-1D-myo-inositol tetrakisphosphate. The isomeric configuration of diphospho-1D-myo-inositol tetrakisphosphate is unknown.