ISSN:
1432-2145
Keywords:
Key words Zea mays sperm
;
Calcium (Ca2+)
;
Calmodulin
;
Calreticulin
;
Protein phosphorylation
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract To examine possible calcium (Ca2+)-mediated prefertilization events in male gametes of higher plants, we studied protein phosphorylation and the Ca2+-binding proteins, calmodulin and calreticulin, in sperm cells isolated from maize (Zea mays L.) pollen in the presence and absence of Ca2+. Using immunoblotting, we detected calmodulin and calreticulin and Ca2+-induced variations. Exposure of sperm cells to 1 mM Ca2+ for 1 h increased calmodulin content by 136% compared with the control. Ca2+ had little effect on calreticulin at 1 h, but induced a 34% increase after 3 h. Phosphorylation of proteins was low in 1 h-control and Ca2+-treated cells. However, a 13-fold increase in phosphorylation of a 18-kDa protein was found at 12 h in the presence of Ca2+. Ca2+-induced changes in calmodulin, calreticulin and protein phosphorylation observed in maize sperm cells may reflect prefertilization changes in vivo that facilitate sperm cell fusion with egg and central cells.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/s004970050071
