In:
FEBS Letters, Wiley, Vol. 291, No. 1 ( 1991-10-07), p. 113-116
Abstract:
Expression of a transforming Ha‐ ras by dexamethasone in NIH3T3 cells transfected with a glucocorticoid‐inducible Ha‐ ras construct results in a rapid desensitization of the intracellular Ca 2+ ‐mobilizing system to bombesin. This effect precedes the down‐modulation of inositol trisphosphate (IP 3 ) formation by several hours and is, therefore, not explained by an uncoupling of phosphoinositidase C. It is demonstrated that expression of Ha‐ ras attenuates the Ca 2+ ‐release by IP 3 in permeabilized cells. The IP 3 concentration required for half‐maximal Ca 2+ ‐release is doubled in Ha‐ ras expressing cells. Maximal Ca 2+ ‐release which is obtained with 2,μM IP 3 in control cells requires 10μM IP 3 in cells expressing Ha‐ ras . The desensitization of the IP 3 receptors coincides with the desensitization of the Ca 2+ ‐mobilizing system to bombesin. The results indicate that the Ha‐ ras mediated desensitization of the Ca 2+ ‐releasing system to bombesin is — at least in part — caused by a decrease in the affinity of the IP 3 receptor to inositol trisphosphate.
Type of Medium:
Online Resource
ISSN:
0014-5793
,
1873-3468
DOI:
10.1016/0014-5793(91)81116-P
Language:
English
Publisher:
Wiley
Publication Date:
1991
detail.hit.zdb_id:
1460391-3
SSG:
12
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