| First Author | Phillips SV | Year | 2011 |
| Journal | Biochem J | Volume | 438 |
| Issue | 3 | Pages | 545-53 |
| PubMed ID | 21692749 | Mgi Jnum | J:175710 |
| Mgi Id | MGI:5287071 | Doi | 10.1042/BJ20101581 |
| Citation | Phillips SV, et al. (2011) Divergent effect of mammalian PLCzeta in generating Ca2+ oscillations in somatic cells compared with eggs. Biochem J 438(3):545-53 |
| abstractText | Sperm PLCzeta (phospholipase Czeta) is a distinct phosphoinositide-specific PLC isoform that is proposed to be the physiological trigger of egg activation and embryo development at mammalian fertilization. Recombinant PLCzeta has the ability to trigger Ca2+ oscillations when expressed in eggs, but it is not known how PLCzeta activity is regulated in sperm or eggs. In the present study, we have transfected CHO (Chinese-hamster ovary) cells with PLCzeta fused with either YFP (yellow fluorescent protein) or luciferase and found that PLCzeta-transfected cells did not display cytoplasmic Ca2+ oscillations any differently from control cells. PLCzeta expression was not associated with changes in CHO cell resting Ca2+ levels, nor with a significantly changed Ca2+ response to extracellular ATP compared with control cells transfected with either YFP alone, a catalytically inactive PLCzeta or luciferase alone. Sperm extracts containing PLCzeta also failed to cause Ca2+ oscillations in CHO cells. Despite these findings, PLCzeta-transfected CHO cell extracts exhibited high recombinant protein expression and PLC activity. Furthermore, either PLCzeta-transfected CHO cells or derived cell extracts could specifically cause cytoplasmic Ca2+ oscillations when microinjected into mouse eggs. These data suggest that PLCzeta-mediated Ca2+ oscillations may require specific factors that are only present within the egg cytoplasm or be inhibited by factors present only in somatic cell lines. |
