Phosphatidylinositol 4,5-bisphosphate phosphodiesterase in higher plants.

The polyphosphoinositide phosphodiesterase of erythrocyte membranes.

1. A new assay procedure has been devised for measurement of the Ca(2+)-activated polyphosphoinositide phosphodiesterase (phosphatidylinositol polyphosphate phosphodiesterase) activity of erythrocyte ghosts. The ghosts are prepared from cells previously incubated with [(32)P]P(i). They are incubated under appropriate conditions for activation of the phosphodiesterase and the released (32)P-labe...

Degranulation in Mast Cells Activation of Protein Kinase C and An Essential Role for Phospholipase D in the

Die Rolle der Phospholipase D2 in der agonisten- induzierten Endozytose von Opioid Rezeptoren

Dissertation zur Erlangung des akademischen Grades doctor rerum naturalium

The control by Ca2+ of the polyphosphoinositide phosphodiesterase and the Ca2+-pump ATPase in human erythrocytes.

1. Both the Ca(2+)-pump ATPase and the polyphosphoinositide phosphodiesterase of the erythrocyte membrane can, when assayed under appropriate conditions, be activated by Ca(2+) in the micromolar range. We have therefore compared the mechanisms and affinities for Ca(2+) activation of the two enzymes in human erythrocyte membranes, to see whether the polyphosphoinositide phosphodiesterase would b...

Thyroliberin stimulates rapid hydrolysis of phosphatidylinositol 4,5-bisphosphate by a phosphodiesterase in rat mammotropic pituitary cells. Evidence for an early Ca2+-independent action.

Thyrotropin-releasing hormone (TRH; thyroliberin) stimulated rapid hydrolysis of phosphatidylinositol 4,5-bisphosphate [PtdIns(4,5)P2] by a phosphodiesterase (phospholipase C) in GH3 cells, a prolactin-secreting rat pituitary tumour cell line. TRH caused a rapid decrease in the level of PtdIns(4,5)P2 to 60% of control and stimulated a marked transient increase in inositol 1,4,5-trisphosphate, t...