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In PLOS Biology this week you can read about cataloging microbial life, how spider silk is made, a new class of Alzheimer’s drug and an insight intorepairing nerve damage.
Image credit: Tatyana Smirnova
A new Community Page, by Nikos C. Krypides and colleagues, calls for a more unified approach to cataloguing microbial life. This would consist of a comprehensive genomic catalogue of all cultured Bacteria and Archaea by sequencing the type strain of each species. The catalogue would be a great asset for the large-scale discovery of novel genes and functions and to mine microbial genomic data for uses such as combating antibiotic resistance.
Image credit: Anna Rising
How exactly do spiders spin silk? We know that the main components of spider silk are ‘spidroin’ proteins, and we also know these are stored in soluble form and rapidly converted to a material stronger than steel as they leave the spider’s body. Now new research by Marlene Andersson, Anna Rising and colleagues gives some greater insight into this process. Using ion-selective microelectrodes in the silk glands of orb weaver spiders, they showed that a chemical pH gradient is maintained along the gland. Carbonic anhydrase was crucial to maintaining this gradient, and the authors propose a new ‘lock and trigger’ model for spider silk formation by pH-induced rearrangement of the spidroin structure. Read more in the accompanying synopsis.
Image credit: pbio.1001924
A novel class of drug has been identified which could have potential for the treatment of Alzheimer’s diseaseand other neurodegenerative disorders. Researchers have been attempting to inhibit an enzyme called STEP (striatal-enriched protein tyrosine phosphatase) which is overactive in Alzheimer’s disease. In their new research article, Jian Xu, Paul Lombroso and colleagues report their serendipitous discovery of a new STEP inhibitor, which remarkably was elemental sulphur (S8), found as a contaminant in other drugs during a high throughput screen. After converting S8 to a more manageable form to use as a drug, the team tested it in cell culture and in a mouse model. The results were encouraging. See the accompanying synopsis.
Nerves rarely re-grow after severe spinal injury, potentially resulting in permanent paralysis. This is partly because of inhibitory signals which bind to the myelin Nogo receptor, which in turn bind co-receptors such as the protein p75. A research article by Marçal Vilar, Tsung-Chang Sung, and Kuo-Fen Lee sheds new light on the regulation of p75, which needs to dimerize to perform its function. They found that in mice, p75 interacts with a protein called p45, which can block this dimerization. Although a stop codon prevents expression of p45 protein in humans, there are implications for the development of a similar p75 inhibitor for therapeutic uses. Read more in thesynopsis.
read more : http://blogs.plos.org/biologue/2014/08/05/week-plos-biology-20/