Ca(2+)-independent induction of acrosome reaction by protein kinase C in human sperm
| Autor: | Gedalia Paz, Ronit Rotem, Zvi Naor, Z. T. Homonnai, Moshe Kalina, J Lax, Haim Breitbart |
|---|---|
| Rok vydání: | 1992 |
| Předmět: |
Adult
Male medicine.medical_specialty Cell Membrane Permeability Acrosome reaction Down-Regulation Biology PKC alpha Exocytosis Diglycerides chemistry.chemical_compound Alkaloids Endocrinology Capacitation Internal medicine medicine Humans Staurosporine Protein Kinase C Protein kinase C Diacylglycerol kinase Sperm-Ovum Interactions Ionomycin Immunohistochemistry Spermatozoa Sperm Microscopy Electron chemistry Sperm Motility Tetradecanoylphorbol Acetate Calcium Female Acrosome Sperm Capacitation Signal Transduction medicine.drug |
| Zdroj: | Endocrinology. 131:2235-2243 |
| ISSN: | 1945-7170 0013-7227 |
| DOI: | 10.1210/endo.131.5.1425422 |
| Popis: | We report that activated protein kinase C (PKC) can induce acrosome reaction independently of elevated Ca2+. Addition of 12-O-tetradecanoyl phorbol-13-acetate or the membrane-permeable diacylglycerol analog 1-oleoyl-2-acetylglycerol to ejaculated human sperm resulted in stimulation of acrosomal reaction (2- to 3-fold), provided the sperm underwent capacitation. Induction of acrosome reaction by 12-O-tetradecanoyl phorbol-13-acetate was blocked by the PKC inhibitor staurosporine or by down-regulation of endogenous PKC, but not by removal of extracellular Ca2+. Acrosome reaction was also enhanced by the Ca2+ ionophore ionomycin in a Ca(2+)-dependent, PKC-independent fashion. Immunohistochemical analysis with type-specific PKC antibodies revealed the presence of PKC alpha and PKC beta II in the equatorial segment, whereas PKC beta I and PKC epsilon staining was found in the principal piece of the tail. Acrosome reaction, thus far believed to be induced only by elevated Ca2+, can therefore be triggered by activated PKC in a Ca(2+)-independent fashion. The PKC subtypes potentially involved in acrosome reaction are most likely alpha and beta II, whereas the beta I- and epsilon-subspecies might be involved in regulation of flagellar motility of human sperm. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|