TY - JOUR
T1 - 5-Methyltryptamine decreases net accumulation of 32P into the polyphosphoinositides from [γ-32P]ATP in a cell-free system from blowfly salivary glands. Activation of breakdown of the newly synthesized [32P]polyphosphoinositides
AU - Litosch, I.
AU - Calista, C.
AU - Wallis, C.
AU - Fain, J. N.
N1 - Copyright:
Copyright 2004 Elsevier B.V., All rights reserved.
PY - 1986
Y1 - 1986
N2 - Incubation of blowfly salivary gland homogenates with 30 μM [γ-32P]ATP resulted in a rapid, Mg2+-dependent, synthesis of [32P]polyphosphoinositides and [32P]phosphatidic acid. 5-Methyltryptamine, in the presence of 10 μM guanosine 5'-(3-O-thio)trisphosphate, reduced the net accumulation of 32P label into phosphatidylinositol-4,5-P2 and phosphatidylinositol-4-P by 35 and 20%, respectively. 5-Methyltryptamine did not affect synthesis of [32P]phosphatidic acid. Phosphorylation of polyphosphoinositides was not affected by 5-methyltryptamine. In membranes labeled in vitro with [γ-32P]ATP, 5-methyltryptamine stimulated a rapid breakdown of the [32P]polyphosphoinositides. These results indicate that in blowfly salivary gland homogenates, hormone stimulates breakdown of the newly synthesized polyphosphoinositides. In the presence of hormone, the rate of polyphosphoinositide synthesis does not compensate for the rate of polyphosphoinositide degradation.
AB - Incubation of blowfly salivary gland homogenates with 30 μM [γ-32P]ATP resulted in a rapid, Mg2+-dependent, synthesis of [32P]polyphosphoinositides and [32P]phosphatidic acid. 5-Methyltryptamine, in the presence of 10 μM guanosine 5'-(3-O-thio)trisphosphate, reduced the net accumulation of 32P label into phosphatidylinositol-4,5-P2 and phosphatidylinositol-4-P by 35 and 20%, respectively. 5-Methyltryptamine did not affect synthesis of [32P]phosphatidic acid. Phosphorylation of polyphosphoinositides was not affected by 5-methyltryptamine. In membranes labeled in vitro with [γ-32P]ATP, 5-methyltryptamine stimulated a rapid breakdown of the [32P]polyphosphoinositides. These results indicate that in blowfly salivary gland homogenates, hormone stimulates breakdown of the newly synthesized polyphosphoinositides. In the presence of hormone, the rate of polyphosphoinositide synthesis does not compensate for the rate of polyphosphoinositide degradation.
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M3 - Article
C2 - 3001073
AN - SCOPUS:0022572312
VL - 261
SP - 638
EP - 643
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
SN - 0021-9258
IS - 2
ER -