Friday Science Review: May 28, 2010
May 28, 2010
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A Map to Better Beer? The key signaling protein-protein interactions in yeast have been mapped. Mass spectrometry was used to discover the global network between protein kinases and phosphatases to generate the “kinome” map, which contains 1844 interactions. Since yeasts are model organisms with similar signaling pathways as in human cells, this information is relevant for human disease research and drug design. The data set in this study was so large that the research team created software to store and analyze the data (ProHits) and perform statistical analysis (SAINT). Dr. Mike Tyers (Samuel Luenefeld Research Institute) is the lead author of the project described in Science magazine. The entire data set is available at the yeastkinome.org resource website.
Shhhh… Improving Gene Silencing: Micro RNAs (miRNA) control gene expression by interfering with specific RNA transcripts and this requires the Argonaute proteins (AGOs) to perform this function. Researchers isolated the specific key region in AGO and solved the crystal structure of this segment. From this, they discovered that there are intricate and specific molecular interactions between the miRNA and AGO that can dictate specificity. As RNA interference techniques are gaining traction in the therapeutic arena, this discovery may lead to modifications to enhance the effectiveness of these therapies. Dr. Bhushan Nagar led the McGill University research team and published the findings in Nature or check out this video podcast.
E. coli Survival Switch: The AceK protein in some bacteria acts as a switch responding to stressful environmental cues, allowing the bacteria to bypass the energy-producing Krebs cycle and go into a conservation mode. Bacteria such as E. coli and Salmonella can survive in low-nutrient environments such as water. Therefore, the discovery of how AceK works provides a potential target to prevent bacterial contamination in drinking water by inhibiting the ability of the bacteria to go into survival mode. Dr. Zongchao Jia and postdoctoral fellow Dr. Jimin Zheng at Queen’s University solved the structure of the protein that led to understanding the unique properties of the enzyme in having both phosphorylation and de-phosphorylation activities on the same protein. This breakthrough is described in the latest edition of Nature.
Little Buggers All Over Us: The Human Microbiome Jumpstart Reference Strains Consortium is trying to catalog all the microbes in the human body. We are covered by millions and millions of these little critters – as many as 10x more microbes than the number of cells in our body, but they’re not necessarily bad for us. They actually play important roles in protecting against infection, aid with digestion, developing our immune system and keeping us healthy. So far, 178 genomes have been sequenced with the goal to sequence around 900 genomes. The NIH initiated the project and Dr. Michael Surette and his team at the University of Calgary is a major contributor to the study. The first phase of this initiative is published in Science.
Genomic Modifications in Stem Cells: To further understand stem cells and embryonic development, scientists took a closer look at how the structural organization of genomic DNA (chromatin and histones) plays a role in determining what tissue they become. They identified and compared specific modifications across the genome that either activates or represses gene expression in different stem cells. The value of this information is that it suggests differential regulatory mechanisms controlling development and depends on the specific stem cell lineage. The safety of regenerative medicine lies in these types of studies in basic stem cell biology. Developmental biologist Dr. Janet Rossant at The Hospital for Sick Children led the study, which appears in the Proceedings of the National Academy of Sciences. Also, congratulations to Dr. Rossant as a recent recipient of the 2010 Premier’s Summit Award for Medical Research.
Improving Alzheimer Immunotherapy: Delivering antibodies against amyloid-beta peptide (Abeta) directly into the brain is more effective than systemic delivery in reducing amyloid plaques, as demonstrated in a mouse model. In this novel approach, transcranial focused ultrasound (FUS) was applied to improve permeability of the blood brain barrier without the need for high doses of the antibody. The researchers administered the therapeutic antibody intravenously along with a contrast agent to follow the progress via MRI imaging. Using this MRI guided FUS method, they could see the contrast agent enter the brain within minutes and amyloid pathology was improved in the mouse model after four days. Drs. Kullervo Hynynen and Isabelle Aubert at Sunnybrook Research Institute published their study on-line in PLoS One.