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Archive - Mar 26, 2017

New Study Resolves Structure of Human Protein (CFTR) That Causes Cystic Fibrosis

Scientists at The Rockefeller University have mapped the three-dimensional structure for one of the more notorious disease-causing molecules in the human body: the protein responsible for the genetic disorder cystic fibrosis. In research described in the March 23, 2017 issue of Cell, the researchers report that the human structure is almost identical to one they have determined previously for the zebrafish version of the protein. The Cell article is titled “Molecular Structure of the Human CFTR Ion Channel.” “With these detailed new reconstructions, we can begin to understand how this protein functions normally, and how errors within it cause cystic fibrosis,” says Jue Chen, Ph.D., William E. Ford Professor at Rockefeller. “We now know that the conclusions we drew from our previous work in zebrafish also apply to us.” Cystic fibrosis arises from mutations in a single gene, which encodes a protein that forms a channel through which chloride ions pass in and out of cells. Errors in this protein, called the cystic fibrosis transmembrane conductance regulator (CFTR), can lead to the accumulation of thick, sticky mucus. The buildup of mucus has the deadliest effects in the lungs, where it can cause potentially fatal breathing problems or respiratory infections. Although cystic fibrosis is a human disorder, many animals also express CFTR. When the human protein proved difficult to work with in the lab, Dr. Chen and her colleagues instead turned to the more-cooperative zebrafish version. Among other things, they used it to map the location of disease-causing mutations—findings that can now be applied to studying how the faulty human protein can spark disease.

Over 100 Genes Related to Memory Are Identified

Researchers have identified more than 100 genes important for memory in people. The study is the first to identify correlations between gene data and brain activity during memory processing, providing a new window into human memory. "This is very exciting because the identification of these gene-to-behavior relationships opens up new research avenues for testing the role of these genes in specific aspects of memory function and dysfunction," says Genevieve Konopka, Ph.D., of the University of Texas (UT) Southwestern, who is presented this new work in San Francisco on March 26, 2017 at the Cognitive Neuroscience Society (CNS) annual conference. "It means we are closer to understanding the molecular mechanisms supporting human memory and thus will be able to use this information someday to assist with all kinds of memory issues." The study is part of the nascent but growing field of "imaging genetics," which aims to relate genetic variation to variation in brain anatomy and function. "Genes shape the anatomy and functional organization of the brain, and these structural and functional characteristics of the brain give rise to the observable behaviors," says Evelina Fedorenko, Ph.D., of Harvard Medical School and Massachusetts General Hospital, who is chairing the symposium on imaging genetics at the CNS conference. While past work has aimed to connect behavior to genes, researchers have lacked neural markers, which can provide a powerful bridge between the two. "Probing the genes-brain relationship is likely to yield a rich understanding of the human cognitive and neural architecture, including insights into human uniqueness in the animal kingdom," says Dr. Fedorenko. Dr. Konopka and Dr.

Annual ISEV Meeting on Extracellular Vesicles (Including Exosomes) in Toronto May 17-21

The annual meeting of the International Society for Extracellular Vesicles (ISEV 2017) (https://isev.site-ym.com/), will take place from May 17-21 in Toronto, Canada, and will offer an unparalleled opportunity to network with, and learn from, the preeminent leaders in extracellular vesicle (EV) research. To register for this meeting, please click here (https://isev.site-ym.com/page/ISEV2017Registration). The scope and quality of the anticipated scientific exchange make ISEV 2017 the largest and the premier meeting in EV research in the world. This event features five days of the best in vesicle science covering all aspects of basic, clinical, and translational research. The research theme includes diverse areas of science encompassing rare and neglected diseases, infectious disease, coagulation, cancer, neuroscience, cardiovascular studies, immunology, regenerative medicine, virology, parasitology, and more. The overall theme of ISEV 2017 is “Diversity of EV Composition and Function in Disease Diagnosis and Therapeutics.” Amidst growing interest in the promise of EVs in disease detection and treatment, ISEV 2017 will bring scientists and clinicians in medical and biotechnology communities together to translate their research. No other meeting in the world offers the scope, participation level, and thematic focus of ISEV 2017 concentrating and cross-pollinating scientific investigations in the field of disease biomarkers and therapeutic tools by disseminating cutting-edge developments in EV research. Among the plenary speakers scheduled to address the meeting are Clotilde Thery, Ph.D. (Research Director, Institut Curie), Philip Stahl, Ph.D. (Professor Emeritus of Cell Biology and Physiology, Washington University School of Medicine), Thomas Thum M.D., Ph.D. (Professor of Cardiology, Imperial College-London), Jeff Wrana, Ph.D.

New 3D Method of De Novo Genome Assembly Demonstrated; Sequencing of Aedes aegypti Mosquito Genome Used As Proof of Principle for Significantly Faster and Cheaper Method

A team spanning Baylor College of Medicine, Rice University, Texas Children's Hospital, and the Broad Institute of MIT and Harvard has developed a new way to sequence genomes, which can assemble the genome of an organism, entirely from scratch, dramatically cheaper and faster. While there is much excitement about the so-called "$1000 genome" in medicine, when a doctor orders the DNA sequence of a patient, the test merely compares fragments of DNA from the patient to a reference genome. The task of generating a reference genome from scratch is an entirely different matter; for instance, the original human genome project took 10 years and cost $4 billion. The ability to quickly and easily generate a reference genome from scratch would open the door to creating reference genomes for everything from patients to tumors to all species on earth. In an article published online on March 23, 2017 in Science, the multi-institutional team reports a method -- called 3D genome assembly -- that can create a human reference genome, entirely from scratch, for less than $10,000. The article is titled “De novo Assembly of the Aedes aegypti Genome Using Hi-C Yields Chromosome-Length Scaffolds.” To illustrate the power of 3D genome assembly, the researchers have assembled the 1.2 billion letter genome of the Aedes aegypti mosquito, which carries the Zika virus, producing the first end-to-end assembly of each of its three chromosomes. The new genome will enable scientists to better combat the Zika outbreak by identifying vulnerabilities in the mosquito that the virus uses to spread. The human genome is a sequence of 6 billion chemical letters, called base-pairs, divided up among 23 pairs of chromosomes.

MIT Scientists ID Brain Circuit That Drives Pleasure-Inducing Behavior; Nobel Prize Winner Leads Ground-Breaking Study of Central Amygdala

Science commentary]Scientists have long believed that the central amygdala, a structure located deep within the brain, is linked with fear and responses to unpleasant events. However, a team of MIT neuroscientists has now discovered a circuit in this structure that responds to rewarding events. In a study of mice, activating this circuit with certain stimuli made the animals seek those stimuli further. The researchers also found a circuit that controls responses to fearful events, but most of the neurons in the central amygdala are involved in the reward circuit, they report. “It’s surprising that positive-behavior-promoting subsets are so abundant, which is contrary to what many people in the field have been thinking,” says Susumu Tonegawa, Ph.D., the Picower Professor of Biology and Neuroscience and director of the RIKEN-MIT Center for Neural Circuit Genetics at the Picower Institute for Learning and Memory. Dr. Tonegawa, who won the Nobel Prize for Physiology or Medicine in 1987 for his discovery of the genetic mechanism that produces antibody diversity is the senior author of the study, which appears in the March 22, 2017 issue of Neuron. The paper’s lead authors are graduate students Joshua Kim and Xiangyu Zhang. The article is titled “Basolateral to Central Amygdala Neural Circuits for Appetitive Behaviors.” The paper builds on a study published last year in which Tonegawa’s lab identified two distinct populations of neurons in a different part of the amygdala, known as the basolateral amygdala (BLA). These two populations are genetically programmed to encode either fearful or happy memories.