A mutation in the tRNA(Leu)(UUR) gene associated with the MELAS subgroup of mitochondrial encephalomyopathies
Article Abstract:
Mitochondria are small organelles located within cells that carry enzymes essential for cell survival. They have their own DNA and RNA in which, as in all genetic material, defects can occur. Several disorders that result from such defects are known, including MELAS. This is an acronym for Mitochondrial myopathy (muscle disorders due to mitochondrial dysfunction), Encephalopathy (brain abnormalities), Lactic Acidosis (a metabolic disorder), and Stroke-like episodes. In two other disorders of similar origin, mitochondrial tRNA (the RNA to which amino acids are attached before they are made into peptides through polymerization) has been shown to be affected. To learn whether this is the case in MELAS, genetic material from a MELAS patient was evaluated. A mutation was found in the region of a gene that codes for a component of mitochondrial tRNA. After a simple diagnostic test was developed that used the new knowledge, two other members of the patient's family were tested; both had the mutation. However, five other MELAS patients did not exhibit this mutation, indicating that other causes of the syndrome exist. People with the mutation also displayed normal mitochondrial genomes, a condition called heteroplasmy. While the direct physiological consequences are not known, it appears that MELAS is the result of this mutation. (Consumer Summary produced by Reliance Medical Information, Inc.)
Publication Name: Nature
Subject: Zoology and wildlife conservation
ISSN: 0028-0836
Year: 1990
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A signal chain of events
Article Abstract:
Barry Dickson and his colleagues have suggested a pathway for the transmission of molecular information through the surface of a cell to nuclear proto-oncogene products via several intermediaries. This pathway is suggested as the primary route for the transduction of molecular signals from tyrosine kinases at the cell surface. It may be a network rather than a linear pathway, appearing linear because variation in the relative weight given to input signals would cause a different branch of the network to be chosen.
Publication Name: Nature
Subject: Zoology and wildlife conservation
ISSN: 0028-0836
Year: 1992
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Primary LAMP-2 deficiency causes X-linked vacuolar cardiomyopathy and myopathy (Danon disease)
Article Abstract:
Research is presented concerning the causes of Danon's disease and the influence of a deficiency of lysosome-associated membrane protein-2 in the development of intra-cytoplasmic vacuoles which characterize the disease.
Publication Name: Nature
Subject: Zoology and wildlife conservation
ISSN: 0028-0836
Year: 2000
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