James E. Ferrell
My research focuses on the web of protein kinases that regulates the entry of cells into the cell cycle and the progress of cells from one phase of the cell cycle to another. The biological system my laboratory most often uses is the Xenopus laevis oocyte, which offers a wealth of technical advantages for studies of cell cycle transitions.
There are two main projects underway in my laboratory:
1. MAP kinase regulation and biological function.
MAP kinases (mitogen activated protein kinases) are evolutionarily conserved protein kinases that shuttle signals from the cytoplasm to the nucleus. MAP kinase activation is required for mitogenesis, and constitutive activation of MAP kinase causes malignant transformation. MAP kinases are also essential for cell fate induction and for the normal functions of terminally differentiated cells. The prevailing model is that MAP kinase activation tells a cell to "do something," and other factors--concomitant signals or cell lineage commitments, for example--determine what that "something" is.
My laboratory group is examining the mechanism and significance of MAP kinase activation and translocation, through a combination of biochemical, molecular biological, and genetic approaches: 1)Activation of Cdc2 by MAP kinase; 2)Regulation of MK phosphatase; 3)Interaction of MAP kinase and Rsk; and 4)Dynamics of the MAP kinase cascade.
2. NimA/Xnek1 and the G2-M transition.
In the filamentous fungus Aspergillus nidulans, a protein kinase called NimA appears to be as essential to the G2-M transition as is the Cdc2/cyclin B complex. My group has cloned three possible NimA homologs from Xenopus, and is studying their regulation and function in Xenopus meiotic and mitotic cell cycles. Preliminary evidence indicates that at least one of these possible homologs--a protein kinase called Xnek1--undergoes phosphorylation and dephosphorylation at specific points in the cell cycle. We hope to determine whether Xnek1/NimA-like protein kinases are universal M phase regulators, like Cdc2, and to determine how Xnek1 is regulated and coordinated with Cdc2.