title: Detection of phospholipase Cgamma in sea urchin eggs.
abstract: Phosphorylation on tyrosine and turnover of polyphosphoinositide metabolism are rapidly stimulated after fertilization. However, the interconnection between these pathways remains to be determined. In the present paper it is demonstrated that eggs of two different sea urchin species contain tyrosine phosphorylated proteins with calcium-sensitive phospholipase C activity. We have investigated whether phospholipase Cgamma (PLCgamma), characteristic of tyrosine kinase receptors, could be responsible for this activity. Western blot and immunocytochemistry performed with antibodies directed against PLCgamma revealed the presence of this protein in cortical regions. It was also observed that PLCgamma displayed calcium-sensitive activity. The present results suggest that PLCgamma may be part of the cascade of events leading to the calcium signal responsible for egg activation at fertilization.
authors.affiliation: Groupe de Recherche sur l'Interaction Gamétique, Faculté de Médecine Pasteur, Nice, France.
authors.forename: C
authors.initials: C
authors.lastname: De Nadai
authors.forename: K
authors.initials: K
authors.lastname: Cailliau
authors.forename: D
authors.initials: D
authors.lastname: Epel
authors.forename: B
authors.initials: B
authors.lastname: Ciapa
mesh_terms: D000818:Animals; D015153:Blotting, Western; D002118:Calcium / Q000378:metabolism; D005306:Fertilization / Q000502:physiology; D007150:Immunohistochemistry; D008854:Microscopy, Electron; D010063:Ovum / Q000201:enzymology*; D010766:Phosphorylation; D011233:Precipitin Tests; D011505:Protein-Tyrosine Kinases / Q000032:analysis; D012617:Sea Urchins / Q000196:embryology* / Q000276:immunology; D015398:Signal Transduction; D010738:Type C Phospholipases / Q000378:metabolism*; D014443:Tyrosine / Q000502:physiology
chemical_list: D014443:Tyrosine; D011505:Protein-Tyrosine Kinases; D010738:Type C Phospholipases; D002118:Calcium