Release of Ca2+ from plant hypocotyl microsomes by inositol-1,4,5-trisphosphate.
Biochem Biophys Res Commun
; 130(3): 1241-6, 1985 Aug 15.
Article
in En
| MEDLINE
| ID: mdl-3875346
ABSTRACT
The effect of inositol-1,4,5-trisphosphate on Ca2+ release from microsomes isolated from dark-grown zucchini (Cucurbita pepo L.) hypocotyls was studied. Up to 30% of the Ca2+ taken up by the microsomes in the presence of 2mM ATP, was released by mumolar concentrations of inositol-1,4, 5-trisphosphate. This release was very rapid (less than 0.5 min) and was followed by a slower re-uptake of Ca2+. The microsomal levels of Ca2+ previously attained were not re-established within 5 min. External concentration of free Ca2+ was maintained in the 10(-8)M region during the release. This is the first time that inositol-1,4,5-trisphosphate has been shown to have a regulatory effect on Ca2+ in plant membrane fractions. Phosphoinositides may be important in signal transduction in plant cells, by altering the cytoplasmic Ca2+ activity, a function already known in animal cells.
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Database:
MEDLINE
Main subject:
Plants
/
Sugar Phosphates
/
Calcium
/
Inositol Phosphates
/
Microsomes
Language:
En
Year:
1985
Type:
Article