Identification of in vivo targets of a novel cytoplasmic poly(A) polymerase and its in vivo analysis.

Dr. C. Eckmann

Project Summary:

Germline development is a fundamental feature of all sexually reproducing organisms and relies heavily on post-transcriptional mRNA regulation. Translation and stability of many mRNAs throughout development can occur through regulated changes in poly(A) tail length, which in turn can be influenced by the action of conserved RNA-binding proteins. Many known RNA-binding proteins negatively regulate translation of their target mRNAs. Some keep their target mRNAs in a dormant stage with a short poly(A) tail. Our recent work revealed a novel hetero-dimeric cytoplasmic poly(A) polymerase that has the potential to activate dormant mRNAs by conferring a long poly(A) tail. This cytoPAP complex is formed by GLD-2 and GLD-3, reflecting a catalytic moiety and a distinct RNA-binding protein, respectively. The central objective of our proposed research is to define the target mRNA-binding potential of this cytoPAP complex. Furthermore, we address the molecular mechanism of these proteins in detail to understand how they control the development of the germ line. By focusing on the RNA-binding protein GLD-3 we will characterize not only a member of the Bicaudal C protein family; in addition, we aim to provide insight into formation and biological function of regulatory cytoplasmic poly(A) polymerases.

Selected publications (2007-09):
Suh N., B. Jedamzik, C.R. Eckmann, M. Wickens, and J. Kimble 2006 An RNA regulatory switch controls the mitosis/meiosis decision in Caenorhabditis elegans. PNAS. 103: 15108-15112

M. Schmid, B. Kuechler and C.R. Eckmann 2009 Two conserved regulatory cytoplasmic poly(A) polymerases, GLD-2 and GLD-4, regulate meiotic progression in C. elegans. Genes & Development, 23(7): 824-836

M. Harterink, A. Rybarska, M.Schmid, B. Jedamzik, A. Kupinski and C.R. Eckmann 2009 GLS-1, a novel P granule component, modulates a network of conserved RNA regulators to influence germ cell fate decisions. PLoS Genetics, 5(5): e1000494

C. P. Brangwynne, C.R. Eckmann, D.S. Courson, A. Rybarska, C. Hoege, J. Gharakhani, F. Jülicher, A.A. Hyman (2009) Germline P granules are liquid droplets that localize by controlled dissolution/condensation. Science 324(5935): 1729-1732

B. Jedamzik and C.R. Eckmann 2009 Analysis of in vivo protein complexes by coimmunoprecipitation from Caenorhabditis elegans. CSH Protocols, doi:10.1101/pdb.prot5299 (in press)

B. Jedamzik and C.R. Eckmann 2009 Analysis of RNA-protein complexes by RNA coimmunoprecipitation and RT-PCR analysis from Caenorhabditis elegans. CSH Protocols, doi:10.1101/pdb.prot5300 (in press)