Expression of 1L-myo-Inositol -1-Phosphate Synthase (EC 5.5.1.4) is Deregulated in the Cerebellum of Curly Tail Mutant Mice

Abstract

Previous research, defining spatial control of inositol phosphate biosynthesis in the developing brain of CBA (normal) and CT [curly tail (ct-CT) and straight tail (st-CT)] mutant mice implicated a role for 1l-myo-inositol 1-phosphate synthase (MIP) in normal functioning of the central nervous system. Biochemical research indicated that MIP enzymatic activity, conversion of glucose 6-phosphate into inositol phosphate, is highest in the cerebellum of ct-CT and lowest in st-CT, when compared to that of CBA mice. Here, we utilized microscopic and biochemical investigations to analyze and extend previous findings of MIP expression in the cerebellum. Results of this research indicated that MIP expression correlates, well, with its enzymatic activity in the cerebellum of CBA and CT mutant mice. Statistical analyses of fluorescent micrographs detected a significant difference in fluorescence intensity between MIP from ct-CT, st-CT, and CBA mice. These data support vital links between inositol phosphate biosynthesis, MIP expression, and normal functioning of the cerebellum. Moreover, published data, identifying significant behavioral differences in the CT mutant, as well as data linking motor and non-motor cerebellar functions to abnormal levels of inositol, support the conclusion that aspects of normal cerebellar functions require temporal and spatial control of inositol phosphate biosynthesis, MIP expression.