* Present address and author to whom correspondence should be addressed: Massey Cancer Center, PO Box 980230. Medical College of Virginia, Richmond, VA 23298-0230, USA.
Sea urchin fertilization stimulates CaM kinase-II (multifunctional [type II] Ca2+/CaM kinase) activity and association with p34cdc2
Article first published online: 27 OCT 2003
Development, Growth & Differentiation
Volume 37, Issue 5, pages 589–596, October 1995
How to Cite
Tombes, R. M. and Peppers, L. S. (1995), Sea urchin fertilization stimulates CaM kinase-II (multifunctional [type II] Ca2+/CaM kinase) activity and association with p34cdc2. Development, Growth & Differentiation, 37: 589–596. doi: 10.1046/j.1440-169X.1995.00014.x
- Issue published online: 27 OCT 2003
- Article first published online: 27 OCT 2003
- Received 10 June 1995; accepted 11 July 1995.
- CaM kinase;
- sea urchin
Upon fertilization, the sea urchin egg synthesizes proteins which impart a Ca2+ dependence to M-phase onset. A potential target of this Ca2+ dependence may be CaM kinase-II (the multifunctional [type II] Ca2+/calmodulin [CaM]-dependent protein kinase) which is necessary for nuclear envelope breakdown in fertilized sea urchin eggs. This study was intended to determine whether sea urchin CaMK-II is activated after fertilization and whether it interacts with other known M-phase regulators, such as p34cdc2. We report that total CaMK-II activity, measured by solution assays, increases after fertilization, peaking just prior to cleavage. Interestingly, total CaMK-II activity continues to fluctuate, peaking again prior to second and third cleavage. Gel assays also reveal enhanced levels of the 56 and 62 kDa potential CaMK-II phosphoproteins after fertilization. Finally, CaMK-II activity and only the 62 kDa phosphoprotein physically associate with p34cdc2, but again only after fertilization. These changes in CaMK-II activity and p34cdc2-association after fertilization may ensure that Ca2+ signals are targeted to the M-phase machinery at the appropriate developmental times.