Distribution and neuronal expression of phosphatidylinositol phosphate kinase IIgamma in the mouse brain.
The role of cellular phosphatidylinositol 5-phosphate (PtdIns5P), as a signalling molecule or as a substrate for the production of small, compartmentalized pools of phosphatidylinositol 4,5-bisphosphate [PtdIns(4,5)P(2)], may be dependent on cell type and subcellular localization. PtdIns5P levels are primarily regulated by the PtdIns5P 4-kinases (type II PIP kinases or PIP4Ks), and we have investigated the expression and localization in the brain of the least-studied PIP4K isoform, PIP4Kgamma. In situ hybridization and immunohistochemistry, using antisense oligonucleotide probes and a PIP4Kgamma-specific antibody, revealed that this isoform has a restricted CNS expression profile. The use of antibodies to different cell markers showed that this expression is limited to neurons, particularly the cerebellar Purkinje cells, pyramidal cells of the hippocampus, large neuronal cell types in the cerebral cortex including pyramidal cells, and mitral cells in the olfactory bulb and is not expressed in cerebellar, hippocampal formation, or olfactory bulb granule cells. In neurons expressing this enzyme, PIP4Kgamma has a vesicular distribution and shows partial colocalization with markers of cellular compartments of the endomembrane trafficking pathway. The PIP4Kgamma isoform expression is established after day 7 of postnatal development. Overall, our data suggest that PIP4Kgamma may have a role in neuron function, specifically in the regulation of vesicular transport, in specific regions of the developed brain.
Clarke
Jonathan H
JH
Department of Pharmacology, University of Cambridge, Tennis Court Road, Cambridge, CB2 1PD United Kingdom. jhc30@cam.ac.uk
Emson
Piers C
PC
Irvine
Robin F
RF
D000818:Animals; D000831:Animals, Newborn; D001921:Brain / Q000201:enzymology* / Q000254:growth & development* / Q000378:metabolism; D002478:Cells, Cultured; D022162:Cytoplasmic Vesicles / Q000201:enzymology / Q000378:metabolism; D005727:Ganglia, Spinal / Q000201:enzymology / Q000378:metabolism; D007527:Isoenzymes / Q000378:metabolism; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D009474:Neurons / Q000201:enzymology* / Q000378:metabolism; D017853:Phosphotransferases (Alcohol Group Acceptor) / Q000378:metabolism*; D013116:Spinal Cord / Q000201:enzymology / Q000378:metabolism; D013347:Subcellular Fractions / Q000201:enzymology / Q000378:metabolism; D013997:Time Factors
D007527:Isoenzymes; D017853:Phosphotransferases (Alcohol Group Acceptor); C546220:Pip4k2c protein, mouse