Elucidating the Role of CaMKK in Cell Cycle and Cell Fate using a C. elegans model
Abstract
The mammalian calmodulin-dependent protein kinase kinases (CaMKKs) have been shown to phosphorylate and activate the calmodulin-dependent protein kinases I and IV (CaMKI, CaMKIV), leading to transcription of a variety of genes important in cell cycle regulation. Using a C. elegans homologue (ceCaMKK), we are investigating the importance of this proposed cascade to cell cycle, cell fate and development in the context of a well-defined multicellular organism. By generating transgenic worms with reporter proteins controlled by the ceCaMKK promoter, gene expression has been demonstrated in the excretory cell, vulval muscle cells and several neurons of adult hermaphrodites, in the hypodermal cells of Ll/L2 larvae, and in several male-specific tail cells. To examine this pathway biochemically, we have cloned the ceCaMKK and ceCaMKI cDNAs, and produced recombinant proteins by prokaryotic expression methods. Both mammalian and C. elegans CaMKKs can phosphorylate either species' CaMKI homologue specifically on the activation loop (Tl 77 in human, TI 79 in C. elegans) in vitro. These results indicate a tunctional homology between the mammalian and C. elegans caimodulin dependent kinases, and demonstrate the existence of a calmodulin dependent kinase cascade in the worm. We have used these proteins to begin a screen for cascade targets, but further work remains to reveal the biological functions of this signaling pathway.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 01, 2000
- Accession Number
- ADB282127
Entities
People
- A. Means
- Ethan Corcoran
Organizations
- Duke University Hospital