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[
Nature,
1997]
Who scapes the lurking sepent's mortal sting? Not he that sets his foot upon her back. Even the smallest of worms will turn, when trodden on.
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[
Neuron,
2002]
A variety of secreted components have been identified as retrograde signals mediating diverse aspects of synaptic development, maintenance, and plasticity; however, little is known about the mechanisms mediating the release of secreted retrograde signals. Doi and Iwasaki (this issue of Neuron) implicate AEX-1, a protein distantly related to the UNC-13/Munc13 family, as an attractive candidate regulator of the retrograde release machinery in muscle.
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[
Trends Microbiol,
1999]
As outlined by Michal Jazwinski in his recent review, multiple pathways appear to play a role in determining yeast longevity. One mechanism involves the illegitimate replication of extrachromosomal rDNA circles to toxic levels. A similar sequence of events involving excision, circularization and unfettered replication of mitochondrial (mt) DNA (called senDNA) induces senescence in the fungus Podospora anserina.
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[
Worm,
2014]
Animal development is driven by robust, cell-specific gene expression programs. Understanding mechanistically how a single transcription factor (TF) can govern distinct programs with exquisite precision is a major challenge. We view TFs as signal integrators, taking information from co-regulator interactions, post-translational modifications, other transcription factors, chromatin state, DNA sequence and in some cases, specific noncovalent ligands, to determine the collection of genes regulated by a TF at any given time. Here, we describe a reductionist approach to combinatorial transcriptional regulation, focusing on a single C. elegans TF, the nuclear hormone receptor NHR-25, and a single post-translational modification, SUMO. We suggest that the ratio of sumoylated to unsumoylated NHR-25 could specify a switch-like cell-fate decision during vulval development. Direct examination of this "SUMO ratio" in vivo is challenging and we discuss possible solutions going forward. We also consider how sumoylation of multiple substrates might be coordinated during vulval development. Finally, we note that iteration of this approach could leverage our sumoylation findings to define the roles of other effectors of NHR-25 in the developing vulva and in other tissues.
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[
Science,
1994]
Like people, cells die in different ways: accident, murder, old age, even suicide. In fact, cellular suicide isn't just a curiosity, it's necessary for the health of the organism. During embryonic development, for example, it helps weed out superfluous nerve cells, as well as immune cells that might attack and damage the body's own tissues. Like a spy-plane pilot who carries a little vial of poison under his seat in case he's captured, cells carry in their nuclei a genetic program for suicide that can be set in motion, should the cell receive orders to self-destruct. Now, after years of eluding researchers, the genes that carry out the suicide program are coming into the light...
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[
Nature,
1993]
Twenty years ago Sydney Brenner described an electrode-less plan for attacking the problems of neural development and physiology in the small nematode Caenorhabditis elegans. He proposed to set the groundwork by reconstructing the entire nervous system of the worm by serial section electron microscopy. Given the resulting wiring diagram, he thought it might be possible to make guesses as to how the nervous system worked. A second aspect of his plan was genetics: single-gene mutants exhibiting aberrant behaviour, such as uncoordinated movement, were to be analysed to address the question of how genes specify development and function of the nervous system. In two papers beginning on page 334 of this issue, McIntire et al. demonstrate that work on Brenner's plan, with a few tricks added over the years, is progressing very nicely.
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[
Cell,
2001]
Hypoxia-inducible factor 1 (HIF-1) is a global regulator of cellular and systemic O2 homeostasis in animals. A molecular basis for O2 regulated expression of the HIF-1 alpha subunit has now been determined, providing a mechanism for changes in gene expression in response to changes in cellular oxygenation.
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[
Curr Biol,
2010]
A screen for axonal cargo mislocalization in Caenorhabditis elegans neurons implicates the cyclin-dependent kinases CDK-5 and PCT-1 and the cyclin CCY-1 in the regulation of the microtubule motor cytoplasmic dynein.
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[
Cell,
2009]
The serine/threonine kinase Akt is a focal point in signaling pathways that control cell tumorigenesis and insulin resistance. In this issue, Padmanabhan et al. (2009) identify a phosphatase regulatory subunit PPTR-1 that regulates the insulin/insulin-like growth factor 1 pathway by counteracting Akt activity in worms and mammalian cells.
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[
Cell,
2016]
CSR-1 is a germline-expressed C. elegans Argonaute protein essential for viability. In this issue of Cell, Gerson-Gurwitz et al. now demonstrate a role for CSR-1 and its slicer activity in downregulating the levels of maternally deposited mRNAs to fine-tune the expression of proteins with critical roles in embryonic cell divisions.