Nitric oxide coordinates metabolism, growth and development via the Nuclear Receptor E75
07/15/2011
Nitric oxide coordinates metabolism, growth and development via the Nuclear Receptor E75 Luc�a C�ceres, Aleksandar S. Necakov, Carol Schwartz, Sandra Kimber, Ian J. H. Roberts and Henry M. Krause In this paper, Caceres et al. reveal that the E75/Rev-erb family of nuclear receptors mediates nitric oxide (NO)signaling in the nucleus, and its regulation of development and metabolism. The authors show that in the main neuroendocrine gland of�Drosophila�- the prothoracic gland - NO produced by NO synthase (NOS) blocks the repressive interaction between the E75 nuclear receptor, and it heterodimer partner, DHR3, which, in turn, activates expression of the metamorphosis hormone, ecdysone. Overexpression and underexpression experiments in the prothoracic gland demonstrated the crucial role of NO and E75 nuclear receptor signaling in metamorphosis and metabolism: overexpression lead to massive obesity caused by excessive larval feeding and fat deposition, while disruption lead to a 100-fold decrease in larval size (compared to overexpression counterparts). The relative ratio of condensin I to II determines chromosome shapes Keishi Shintomi and Tatsuya Hirano 129 years after mitotic chromosomes were first described by Walther Flemming, Shintomi and Hirano finally reveal what determines their shape. Metaphase chromosomes shape varies – both during the development of an organism, as well as between different organisms. Shintomi and Hirano precisely manipulated the relative ratios of condensin I and II proteins in Xenpous egg cell-free extracts to demonstrate that these ratios regulate the shape of mitotic chromosomes. They also provided evidence that the cohesion protein helps juxtapose sister chromatid arms by collaborating with condensin I and antagonizing condensin II. Ultimately, the study shows that "chromosome shaping is achieved by an exquisite balance among condensin I (lateral compaction),condensin II (axial shortening) and cohesin (sister chromatid cohesion)." #### Genes & Development is a publication of the Cold Spring Harbor Laboratory Press. The Cold Spring Harbor Laboratory is a private, non-profit, basic research and educational institution. Scientists at the Laboratory conduct groundbreaking research in cancer, neurobiology, plant molecular genetics, genomics and bioinformatics. The Laboratory is recognized internationally for its educational activities, which include an extensive program of scientific meetings and courses that attract more than 8000 scientists to the campus each year. For more information about the Cold Spring Harbor Laboratory, visit www.cshl.org or call the Department of Public Affairs at (516) 367-8455. Contact: Heather Cosel-Pieper Genes & Development Cold Spring Harbor Laboratory tel. (516) 422-4018 fax (516) 422-4093
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