Functional Analysis of Proteins Involved in Translational Regulation during Xenopus oocyte Maturation

Michael Raher
Boston College

Cytoplasmic polyadenylation regulates translational activation of mRNA stored in immature Xenopus oocytes, a process necessary for the start of oocyte maturation. The cytoplasmic polyadenylation element binding protein (CPEB) binds a 3' UTR sequence (the CPE) and interacts with specific proteins in a complex regulatory cascade of phosphorylation and, ultimately, the translation of selected RNAs. Using a yeast two-hybrid screen, several of these involved proteins were identified and cloned, including two of note. DEK, a
chromatin-associated protein found in certain acute myeloid leukemias and juvenile rheumatoid arthritis, has been shown bound, possibly with the aid of spliceosomes, to exons and affecting post-splicing steps in gene expression. X295, a zinc-finger containing, novel protein, has also been discovered to interact with CPEB, and has no homology with known genes. The current goal is to determine if CPEB interacts with these proteins in vivo, and the nature of this prospective interaction. My work with DEK and X295 will help to elucidate the mechanisms of early development and the molecular basis of certain cancers.