archive-edu.com » EDU » R » ROCKEFELLER.EDU

Total: 1631

Choose link from "Titles, links and description words view":

Or switch to "Titles and links view".
  • Scientists identify a key regulator of DNA mutations | Newswire
    specifically binds to AID it can potentially thwart it We used a different approach and different tools yet we said the same things and reached the same conclusions says Papavasiliou head of the Laboratory of Lymphocyte Biology It s pretty powerful stuff In B lymphocytes AID specifically targets a small strip of DNA that encodes an antibody molecule When AID mutates this DNA segment even slightly the altered gene can either give rise to an antibody that binds to a different invader or one that clings tighter to its original target maximizing the chance that it will be effective By regulating how much AID is present in these cells miR 155 helps ensure that there is just enough AID to only mutate this strip of DNA But there s a catch explains Grace Teng a graduate student in the Papavasiliou lab She found that while too little AID impairs the immune system s ability to fight infections too much AID produces neither a more diverse nor a more effective repertoire of antibodies to keep invaders at bay Instead excess levels of the enzyme cause pieces of the antibody genes to swap places with other genes on different chromosomes This process called translocation doesn t always lead to cancer but it is a hallmark of the disease So what s clear from this work is that when you overexpress AID it doesn t generate more mutations to make better antibodies says Papavasiliou It is shunted into a translocation pathway When graduate student Yair Dorsett and postdoc Kevin McBride both members of the Nussenzweig lab either looked at mice in which miR 155 couldn t attach to AID the team altered AID s binding site or mice that couldn t produce miR 155 at all they like the Papavasiliou team didn t

    Original URL path: http://newswire.rockefeller.edu/2008/06/09/scientists-identify-a-key-regulator-of-dna-mutations/ (2016-02-13)
    Open archived version from archive

  • Protein linked to antibodies also has an antiviral function, researchers show | Newswire
    it has not yet been exposed to However antibodies are a fairly new addition to the genome first showing up in sharks AID has been around a lot longer than antibodies Red flag When B cells are infected with a virus they begin to make the AID protein red within four to six days as shown in these time lapse images The protein serves to stop sick B cells from dividing and it flags the cell for clearance by other immune cells Antibodies are a result of a transposon that jumped into the shark genome about 300 million years ago says Papavasiliou head of the Laboratory of Lymphocyte Biology But AID was present before this so we wanted to know what it was doing there Papavasiliou s results published this summer in Immunity suggest that AID originally conferred immunity against viruses Another member of the same protein family called APOBEC3 had been shown to become active in immune system T cells that were infected with HIV The protein was packaged with the new HIV virions where it then mutated the virus s RNA to make it less infectious Papavasiliou wanted to know if perhaps AID functioned in a similar way in B cells where it was expressed Normally AID is only expressed in B cells that are rearranging their antibody genes says Papavasiliou But when we infected B cells with a virus we saw that those cells began making AID After this two things happen First those cells that are infected stop proliferating and second the cells then become marked for clearance by natural killer cells part of the immune system that kills virally infected cells Papavasiliou s data showed that AID s function in antibody diversity is relatively new and its function in viral immunity was AID s original

    Original URL path: http://newswire.rockefeller.edu/2006/08/18/protein-linked-to-antibodies-also-has-an-antiviral-function-researchers-show/ (2016-02-13)
    Open archived version from archive

  • AID | Newswire
    plays an antiviral role in B cells a function it had long before antibodies evolved More Tags AID F Nina Papavasiliou August 23 2004 Science News Genome destroyer identified in the immune system Our bodies have such great capacity to heal it s hard to imagine that we naturally manufacture a product in our immune system that can endanger our own DNA and provide a biological footstep to cancer But

    Original URL path: http://newswire.rockefeller.edu/tag/aid/ (2016-02-13)
    Open archived version from archive

  • Atomic map reveals clues to how cholesterol is made | Newswire
    become a hazard leading to the formation of potentially blood vessel blocking plaques Healthy cholesterol requires balance Too much can cause problems but a certain amount is necessary Not only do cholesterol molecules make cells membranes more resistant to wear and tear the health of the human body as a whole depends on it This waxy substance serves as a precursor to some hormones such as testosterone as well as vitamin D and bile The cholesterol making process in cells requires about 30 chemical reactions and 20 enzymes seven of which are embedded in the cellular membrane The mapping project focused on one of these known as a sterol reductase which helps two electrons travel from a molecule known as NADPH to another molecule that will eventually become cholesterol This type of reaction is known as a reduction Our images revealed two pockets within the enzyme s architecture One contains the NADPH and the other provides access to the cholesterol precursor When in place these molecules are close enough to spark this important step in the synthesis of cholesterol says first author Xiaochun Li a postdoc Li s interest began with a molecule known as the lamin B receptor LBR a sterol reductase in human cells Although LBR was discovered 26 years ago and we know it contributes to cholesterol synthesis no one knew what it looked like or how it works Li says Biologists interested in the structure of molecules crystallize them and then bounce X rays off the crystals Based on the pattern produced by the X rays the scientists then infer the structure of the molecule But LBR did not crystallize well so Li had to find a more accommodating molecule He found a good candidate in the maSR1 protein from a methane eating bacterium then tests

    Original URL path: http://newswire.rockefeller.edu/2014/10/12/atomic-map-reveals-clues-to-how-cholesterol-is-made/ (2016-02-13)
    Open archived version from archive

  • cholesterol | Newswire
    health concerns that has come to dominate the 21st century More Tags cholesterol Jan L Breslow February 12 2007 Campus News Chromosome linked to cholesterol absorption Using strains of mice that only differ from each other on a small area of one chromosome researchers identify two sets of genes important for cholesterol absorption and excretion the balance of which is a key contributor to coronary heart disease susceptibility More Tags cholesterol coronary heart disease Jan L Breslow July 30 2004 Science News Through population screening on the island of Kosrae Rockefeller scientists discover a mutant gene that controls dietary cholesterol absorption Using DNA from 1 000 inhabitants of the Micronesian island of Kosrae Rockefeller University scientists have discovered a mutant gene that affects an individual s absorption of dietary cholesterol The findings are reported in the Journal of Lipid Research The researchers hope their discovery will help tease apart the tangle of genes that control cholesterol absorption one of the factors that contributes to high blood cholesterol levels which are a major risk factor for heart attacks More Tags cholesterol Jeffrey M Friedman April 26 2004 Science News Newly discovered gene controls levels of bad cholesterol in mice Heart disease researchers at Rockefeller University have discovered the function of a gene associated with high cholesterol levels in humans Using mice as test subjects the Rockefeller scientists determined that the gene called Pcsk9 can decrease the number of receptors on liver cells that remove the bad LDL cholesterol from the blood More Tags cholesterol heart disease Jan L Breslow June 25 2002 Science News Proteins that transport cholesterol identified Professor Jan Breslow and colleagues including biomedical fellow Raymond Soccio recently discovered a novel subfamily of the START domain lipid transfer proteins which are thought to shuttle lipids such as cholesterol within

    Original URL path: http://newswire.rockefeller.edu/tag/cholesterol/ (2016-02-13)
    Open archived version from archive

  • enzyme structure | Newswire
    in the cell membrane performs a crucial step in the complex process by which cells produce cholesterol Researchers have examined the enzyme s structure to better understand how it works More Tags cholesterol enzyme structure Günter Blobel sterol reductase Xiaochun Li Search for Categories Science News Awards and Honors Campus News Grants Gifts Topics Video Archive 2015 2014 2013 2012 2011 more About Contact Follow rockefelleruniv Like The Rockefeller University

    Original URL path: http://newswire.rockefeller.edu/tag/enzyme-structure/ (2016-02-13)
    Open archived version from archive

  • Polarized microscopy technique shows new details of how proteins are arranged | Newswire
    give you an idea of what something looks like at a moment in time they can t tell you how its pieces might move The new technique was developed by Simon along with postdoc Alexa Mattheyses graduate student Claire Atkinson and Martin Kampmann a former member of Günter Blobel s Laboratory of Cell Biology who is currently at the University of California San Francisco It takes advantage of the properties of polarized light to show how specific proteins are aligned in relation to one another After genetically attaching fluorescent markers to individual components of the nuclear pore complex the scientists replaced the cell s own copy of the gene that encodes the protein with the new form that has the fluorescent tag Then they used customized microscopes to measure the orientation of the waves of light the fluorescently tagged proteins emitted By combining these measurements with known data about the structure of the complex the scientists can confirm or deny the accuracy of previously suggested models Our experimental approach to the structure is synergistic with other studies being conducted at Rockefeller including analysis with X ray crystallography in Günter s lab and electron microscopy and computer analysis in Mike Rout s lab says Simon By utilizing multiple techniques we are able to get a more precise picture of these complexes than has ever been possible before The scientists used the technique to study nuclear pore complexes in both budding yeast and human cells In the case of the human cells their new data shows that multiple copies of a key building block of the nuclear pore complex the Y shaped subcomplex are arranged head to tail rather than like fence posts confirming a model proposed by Blobel and his colleagues in 2007 As a graduate student with Günter Blobel I

    Original URL path: http://newswire.rockefeller.edu/2011/04/18/polarized-microscopy-technique-shows-new-details-of-how-proteins-are-arranged/ (2016-02-13)
    Open archived version from archive

  • Laboratory of Cellular Biophysics | Newswire
    Rockefeller in 2009 But fundamental questions about how the structures were aligned in relation to the rest of the 30 protein complex remained Researchers at Rockefeller University have now developed a new technique that uses polarized light microscopy to help answer questions about the proteins orientation More Tags Günter Blobel Laboratory of Cell Biology Laboratory of Cellular Biophysics nuclear pore complex Sandy Simon February 25 2010 Science News Imaging studies reveal order in programmed cell death In order to thrive the human body orchestrates a mass suicide of about 10 billion potentially dangerous cells a day New research takes a closer look at programmed cell death called apoptosis and finds order in this process once thought to be an erratically timed sudden collapse More Tags Laboratory of Cellular Biophysics programmed cell death Sanford M Simon November 16 2009 Science News Imaging study shows HIV particles assembling around its genome The genesis of one the planet s most lethal viruses HIV has been caught on tape New imaging experiments show individual HIV genomes strands of RNA docking on the inner membrane of an infected cell wall as they are ensconced by HIV structural proteins More Tags Laboratory of Cellular Biophysics Laboratory

    Original URL path: http://newswire.rockefeller.edu/tag/laboratory-of-cellular-biophysics/ (2016-02-13)
    Open archived version from archive