Early Embryogenesis Cell Fate Specification by CCCH-Type TZF Proteins

C. elegans TZF proteins govern cell fate specification in early embryogenesis:

In the early embryogenesis of C. elegans, the fates of all the founder cells are determined solely through the regulation of maternally supplied mRNA molecules, as zygotic transcription has not yet started: characterizing the mechanism of post-transcriptional mRNA regulation is fundamental, therefore, to a more complete understanding of embryogenesis. Several RNA binding proteins are necessary in this process, among them MEX-5, MEX-6, PIE-1, POS-1 and MEX-1: all are CCCH-type TZF proteins related to TTP. Mutations in the TZF domain of these proteins perturb the expression of several maternal genes, indicating that these proteins influence the stability and/or tune the translational efficiency of maternal mRNAs.

How do the structure and dynamics of MEX-5 and POS-1 define their activity in live animals?

It has been shown that these closely related proteins bind to RNA with different specificities, and that these differences have major implications for the biological activity of each protein. The origin of the different RNA-binding specificities is not yet understood. Our goal is to understand the factors that determine RNA-binding affinity and specificity and their role in embryogenesis. The research in our lab is centered on two of these proteins: MEX-5 and POS-1. Our research characterizes the RNA-binding specificity and develops our understanding of how the RNA-binding activity together with the balance between structure and intrinsic disorder drive their ability to control cell fate.