Researchers discover cell's 'quality control' mechanismJuly 30, 2008Researchers in Japan and Canada have discovered a key component of the quality control mechanism that operates inside human cells - sometimes too well. The breakthrough has significant implications for the development of new treatments for cystic fibrosis (CF) and some other hereditary diseases, the researchers say. Their results were published July 25 in the journal Science. Dr. Kazahiro Nagata and colleagues at Kyoto University and the Japan Science Technology Agency, and Dr. David Thomas and Dr. Gregor Jansen at McGill University in Montreal, have discovered the important role played by an enzyme called ERdj5 inside the cell's endoplasmic reticulum (ER). The ER acts as a sort of packaging plant that folds and prepares proteins for distribution inside or outside the cell. But when proteins are misfolded in the ER, they must be destroyed in a degradation process - and that is where ERdj5 comes into play. "ERdj5 is like a quality control inspector," explained Dr. Thomas, McGill's Chair of Biochemistry and Canada Research Chair in Molecular Genetics. "If you ever owned an AMC Pacer and you now drive a BMW, you know the difference quality control can make. That's what ERdj5 does, it recognizes when a protein has 'manufacturing defects' and degrades it before it can be distributed."
The ERdj5 enzyme is the first protein found to be capable of breaking the disulfide bonds that hold the misfolded proteins together in the ER. Once those bonds are broken, the researchers say ERdj5 also helps other enzymes and molecules break down the misfolded proteins completely so that the constituent amino acids can be recycled for further protein synthesis. "Unfortunately, the mechanism sometimes works a little too well," Dr. Thomas said. "It insists on BMW quality when a Honda would do. For example, some people carry a mutated version of the protein CFTR. The mutated protein is damaged but would still work fine if it were distributed, but in some individuals, the quality control mechanism insists on degrading it. It's the degradation of the protein, not the mutation itself, which causes cystic fibrosis. We're hoping this discovery will open up new avenues of research into treatments for CF." McGill University Science News and Science Current Events Tag Cloud This tag cloud is a visual representation of term frequencies of random science news topics with common terms grouped together and emphasized by their display size. HIV Periodontitis Bypass Surgery Tomato Mosquito Rem Sleep Radiation Solar Wind Cell Division Chronic Obstructive Pulmonary Disease Hepatocellular Carcinoma Pluto Invasive species Pulmonary Embolism Hydrothermal Vent Autism Anesthesia Bad Breath Thyroid Cancer Tinnitus Wireless ADHD Facial Expressions Influenza Vaccine Hydrogen Storage
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Related Quality Control Current Events and Quality Control News Articles New data demonstrate potential for early detection of Alzheimer's disease Data published in the June issue of the Journal of Alzheimer's Disease demonstrated that minimally-invasive biospectroscopy was able to identify changes in oxidative stress (OS) levels in blood plasma, which may prove to be a useful biomarker in the early detection of Alzheimer's disease. Cystic fibrosis testing -- next steps Three reports describing advances in cystic fibrosis genetic testing appear in the May 2009 issue of The Journal of Molecular Diagnostics. MIT: Why we have difficulty recognizing faces in photo negatives Humans excel at recognizing faces, but how we do this has been an abiding mystery in neuroscience and psychology. In an effort to explain our success in this area, researchers are taking a closer look at how and why we fail. Don't be a stranger to yourself One of the most important tasks of the immune system is to identify what is foreign and what is self. If this distinction fails, then the body's own structures will be attacked, the result of which could be an autoimmune disease such as diabetes mellitus type 1 or multiple sclerosis. Tension in the nanoworld A joint team of researchers at CIC nanoGUNE (San Sebastian, Spain) and the Max Planck Institutes of Biochemistry and Plasma Physics (Munich, Germany) report the non-invasive and nanoscale resolved infrared mapping of strain fields in semiconductors. Telemedicine can dramatically improve child sexual assault examinations in rural areas The use of telemedicine can dramatically improve the quality of child sexual assault examinations in rural communities where rates of abuse and neglect are highest - sometimes more than double the statewide rate - a study published in the January issue of the medical journal Pediatrics has found. Cell transplantation and diabetes: New sites, new devices Early attempts at islet cell transplantation to treat diabetes date to the nineteenth century, decades before the discovery of insulin in the 1930s. Lost in translation The enzyme machine that translates a cell's DNA code into the proteins of life is nothing if not an editorial perfectionist. New screening halves the number of children born with Down syndrome A new national screening strategy in Denmark has halved the number of infants born with Down's syndrome and increased the number of infants diagnosed before birth by 30%, according to a study published on bmj.com today. New research helps explain genetics of Parkinson's disease A new study by Narendra et al. suggests that Parkin, the product of the Parkinson's disease-related gene Park2, prompts neuronal survival by clearing the cell of its damaged mitochondria. More Quality Control Current Events and Quality Control News Articles |
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