Deadenylases belong to an expanding family of exoribonucleases involved mainly in mRNA stability and turnover, with the exception of PARN which has additional roles in the biogenesis of several important non-coding RNAs, including miRNAs and piRNAs. Recently, PARN in C. elegans and its homologue PNLDC1 in B. mori were reported as the elusive trimmers mediating piRNA biogenesis. In addition, characterization of mammalian PNLDC1 in comparison to PARN, showed that is specifically expressed in embryonic stem and germ cells, as well as during early embryo development. Moreover, its expression is correlated with epigenetic events mediated by the de novo DNMT3b methyltransferase and knockdown in stem cells upregulates important genes that regulate multipotency. The recent data suggest that at least some new deadenylases may have expanded roles in cell metabolism as regulators of gene expression, through mRNA deadenylation, ncRNAs biogenesis and ncRNA-mediated mRNA targeting, linking essential mechanisms that regulate epigenetic control and transition events during differentiation. The possible roles of mammalian PNLDC1 along those dynamic networks are discussed in the light of new extremely important findings.
Modification, by the addition of lipid-derived groups, is an important determinant of the correct expression of a variety of polypeptides involved in signal transduction. Myristic and palmitic acid are the predominant fatty acids attached to proteins in eucaryotes. Myristic acid is normally linked, cotranslationally, via an amide bond to an N-terminal glycine. In contrast, palmitic acid attachment occurs post-translationally via an alkali-labile ester or thioester linkage...
How does physiological state affect the reproductive behavior of an organism? Two new studies in Caenorhabditis elegans implicate an ancient serotonergic neuronal circuit in the link between these two outputs- reproductive behavior and physiology.
In this issue of The EMBO Journal, Wilson et al (2012) elegantly discovered an important new axis for intestinal homeostasis and cancer, using an RNAi screen to enhance the RAS-induced multivulva (MUV) phenotype in Caenorhabditis elegans.
Gamete fusion is a pivotal step during fertilization to create an organism of the next generation. In C. elegans, since oocytes have no thick egg coat like the zona pellucida, perhaps spermatozoa directly bind to and fuse with the oocyte plasma membrane (PM). Thus, C. elegans is an excellent model to investigate how a spermatozoon and an oocyte fuse together.