Tag Archives: enzyme

Wie unsere Körperzellen gegen Viren kämpfen

Protein versperrt Zugang zum Zellkern, um Erbgut zu schützen

MolekularbiologInnen der Max F. Perutz Laboratories der Universität Wien und der Medizinischen Universität Wien zeigen in Zusammenarbeit mit Kollegen von der ETH Zürich, wie das Eindringen doppelsträngiger RNA wie beispielsweise viralen Erbgutes in den Zellkern verhindert wird. Während der Immunantwort auf eine Virusinfektion wandert das körpereigene Protein ADAR1 aus dem Kern ins Zytoplasma der Zelle, wo es die Virus-RNA so verändert, dass sich damit keine neuen Viren bilden können. Wie dabei jedoch verhindert wird, dass ADAR1 die virale RNA in den Zellkern bringt – wichtig für den Schutz des menschlichen Erbguts – war bisher völlig unklar. In ihrer Studie in PNAS Plus geben die Wiener und Züricher WissenschaftlerInnen eine erste Antwort auf diese Frage. (more…)

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How age opens the gates for Alzheimer’s

With advancing age, highly-evolved brain circuits become susceptible to molecular changes that can lead to neurofibrillary tangles — a hallmark of Alzheimer’s Disease, Yale researchers report the week of March 17 in the Proceedings of the National Academy of Sciences.

The findings not only help to explain why age is such a large risk factor for Alzheimer’s, but why the higher brain circuits regulating cognition are so vulnerable to degeneration while the sensory cortex remains unaffected. (more…)

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New Insight into an Emerging Genome-Editing Tool

Berkeley Researchers Show Expanded Role for Guide RNA in Cas9 Interactions with DNA

The potential is there for bacteria and other microbes to be genetically engineered to perform a cornucopia of valuable goods and services, from the production of safer, more effective medicines and clean, green, sustainable fuels, to the clean-up and restoration of our air, water and land. Cells from eukaryotic organisms can also be modified for research or to fight disease. To achieve these and other worthy goals, the ability to precisely edit the instructions contained within a target’s genome is a must. A powerful new tool for genome editing and gene regulation has emerged in the form of a family of enzymes known as Cas9, which plays a critical role in the bacterial immune system. Cas9 should become an even more valuable tool with the creation of the first detailed picture of its three-dimensional shape by researchers with the Lawrence Berkeley National Laboratory (Berkeley Lab) and the University of California (UC) Berkeley. (more…)

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New Look Inside Cell Nucleus Could Improve Cancer Diagnostics

Researchers have sequenced the entire messenger RNA – the “genetic photocopies” – contained in the nucleus of a single cell, a long-anticipated step toward better cancer diagnostics and other medical applications.

Researchers have successfully isolated and sequenced the entire messenger RNA – the “genetic photocopies” – contained in the nucleus of a single brain cell. This research, published in the journal Proceedings of the National Academy of Sciences, will help researchers better understand how organs function in health and disease and provide another stepping stone toward personalized medicine.   (more…)

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Fatty Acids Crucial to Embryonic Development

Baltimore, MD— One classical question in developmental biology is how different tissue types arise in the correct position of the developing embryo. While one signaling pathway that controls this process has been well described, unexpected findings from a team led by Carnegie’s Steven Farber reveal the importance of polyunsaturated fatty acid metabolism in this process. It is published online December 12 in Developmental Cell.

Fatty acids serve as sources of energy, the building materials of cellular membranes, and as signals for sending messages between cells. Enzymes are needed to activate free fatty acids so that they are useful for cellular processes. The enzymes that perform this function are called acyl-CoA synthetases, often shortened to ACS.  (more…)

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Edited RNA + invasive DNA add individuality

A study in Nature Communications finds that an enzyme that edits RNA may loosen the genome’s control over invasive snippets of DNA that affect how genes are expressed. In fruit flies, that newly understood mechanism appears to contribute to differences among individuals such as eye color and life span.

PROVIDENCE, R.I. [Brown University] — The story of why we are all so different goes well beyond the endless mixing and matching of DNA through breeding. A new study in the journal Nature Communications, for instance, reports a new molecular mechanism of individual variation found in fruit flies that uses components operating in a wide variety of species, including humans. (more…)

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Scientists Reveal Quirky Feature of Lyme Disease Bacteria

Unlike most organisms, they don’t need iron, but they crave manganese

Scientists have confirmed that the pathogen that causes Lyme Disease—unlike any other known organism—can exist without iron, a metal that all other life needs to make proteins and enzymes. Instead of iron, the bacteria substitute manganese to make an essential enzyme, thus eluding immune system defenses that protect the body by starving pathogens of iron.

To cause disease, Borrelia burgdorferi requires unusually high levels of manganese, scientists at Johns Hopkins University (JHU), Woods Hole Oceanographic Institution (WHOI), and the University of Texas reported. Their study, published March 22, 2013, in The Journal of Biological Chemistry, may explain some mysteries about why Lyme Disease is slow-growing and hard to detect and treat. The findings also open the door to search for new therapies to thwart the bacterium by targeting manganese. (more…)

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Gene therapy may aid failing hearts

The potential of gene therapy to boost heart muscle function was explored in a recent University of Washington animal study. The findings suggest that it might be possible to use this approach to treat patients whose hearts have been weakened by heart attacks and other heart conditions.

Michael Regnier, UW professor and vice chair of bioengineering, Charles Murry, director of the Center for Cardiovascular Biology and co-director of the Institute for Stem Cell and Regenerative Medicine, and Sarah Nowakowski, a UW graduate student in bioengineering, led the study. The findings appeared online March 25 in the Proceedings of the National Academy of Sciences. (more…)

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