Rapid turnover rate of phosphoinositides at the front of migrating MDCK cells.
Phosphoinositides (PtdInss) play key roles in cell polarization and motility. With a series of biosensors based on Förster resonance energy transfer, we examined the distribution and metabolism of PtdInss and diacylglycerol (DAG) in stochastically migrating Madin-Darby canine kidney (MDCK) cells. The concentrations of phosphatidylinositol (4,5)-bisphosphate, phosphatidylinositol (3,4,5)-trisphosphate (PIP(3)), phosphatidylinositol (3,4)-bisphosphate, and DAG were higher at the plasma membrane in the front of the cell than at the plasma membrane of the rear of the cell. The difference in the concentrations of PtdInss was estimated to be less than twofold between the front and rear of the migrating MDCK cells. To decode the spatial activities of PtdIns metabolic enzymes from the obtained concentration maps of PtdInss, we developed a one-dimensional reaction diffusion model of PtdIns metabolism. In this model, the activities of phosphatidylinositol monophosphate 5-kinase, phosphatidylinositol 3-kinase, phospholipase C, and PIP(3) 5-phosphatases were higher at the plasma membrane of the front than at the plasma membrane of the rear of the cell. This result suggests that, although the difference in the steady-state level of PtdInss is less than twofold, PtdInss were more rapidly turned over at the front than the rear of the migrating MDCK cells.
Nishioka
Teruko
T
Laboratory of Bioimaging and Cell Signaling, Graduate School of Biostudies, Kyoto University, Kyoto 606-8501, Japan.
Aoki
Kazuhiro
K
Hikake
Kazuhiro
K
Yoshizaki
Hisayoshi
H
Kiyokawa
Etsuko
E
Matsuda
Michiyuki
M
D000818:Animals; D015374:Biosensing Techniques; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism; D002465:Cell Movement; D002855:Chromatography, Thin Layer / Q000379:methods; D004058:Diffusion; D004285:Dogs; D007700:Kinetics; D051379:Mice; D008954:Models, Biological; D008962:Models, Theoretical; D041681:NIH 3T3 Cells; D010716:Phosphatidylinositols / Q000378:metabolism*; D010957:Plasmids / Q000378:metabolism
D010716:Phosphatidylinositols