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MT-CO3
Cytochrome c oxidase subunit III (COX3) is an enzyme that in humans is encoded by the ''MT-CO3'' gene. It is one of main transmembrane subunits of cytochrome c oxidase. It is also one of the three mitochondrial DNA (mtDNA) encoded subunits (MT-CO1, MT-CO2, MT-CO3) of respiratory complex IV. Variants of it have been associated with isolated myopathy, severe encephalomyopathy, Leber hereditary optic neuropathy, mitochondrial complex IV deficiency, and recurrent myoglobinuria . Structure The ''MT-CO3'' gene produces a 30 kDa protein composed of 261 amino acids. COX3, the protein encoded by this gene, is a member of the cytochrome c oxidase subunit 3 family. This protein is located on the inner mitochondrial membrane. COX3 is a multi-pass transmembrane protein: in human, it contains 7 transmembrane domains at positions 15–35, 42–59, 81–101, 127–147, 159–179, 197–217, and 239–259. Function Cytochrome c oxidase () is the terminal enzyme of the respiratory chain of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cytochrome C Oxidase
The enzyme cytochrome c oxidase or Complex IV, (was , now reclassified as a translocasEC 7.1.1.9 is a large transmembrane protein complex found in bacteria, archaea, and mitochondria of eukaryotes. It is the last enzyme in the respiratory electron transport chain of cells located in the membrane. It receives an electron from each of four cytochrome c molecules and transfers them to one oxygen molecule and four protons, producing two molecules of water. In addition to binding the four protons from the inner aqueous phase, it transports another four protons across the membrane, increasing the transmembrane difference of proton electrochemical potential, which the ATP synthase then uses to synthesize ATP. Structure The complex The complex is a large integral membrane protein composed of several metal prosthetic sites and 14 protein subunits in mammals. In mammals, eleven subunits are nuclear in origin, and three are synthesized in the mitochondria. The complex contains two ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cytochrome C Oxidase
The enzyme cytochrome c oxidase or Complex IV, (was , now reclassified as a translocasEC 7.1.1.9 is a large transmembrane protein complex found in bacteria, archaea, and mitochondria of eukaryotes. It is the last enzyme in the respiratory electron transport chain of cells located in the membrane. It receives an electron from each of four cytochrome c molecules and transfers them to one oxygen molecule and four protons, producing two molecules of water. In addition to binding the four protons from the inner aqueous phase, it transports another four protons across the membrane, increasing the transmembrane difference of proton electrochemical potential, which the ATP synthase then uses to synthesize ATP. Structure The complex The complex is a large integral membrane protein composed of several metal prosthetic sites and 14 protein subunits in mammals. In mammals, eleven subunits are nuclear in origin, and three are synthesized in the mitochondria. The complex contains two ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MT-CO1
Cytochrome c oxidase I (COX1) also known as mitochondrially encoded cytochrome c oxidase I (MT-CO1) is a protein that in humans is encoded by the ''MT-CO1'' gene. In other eukaryotes, the gene is called ''COX1'', ''CO1'', or ''COI''. Cytochrome c oxidase I is the main subunit of the cytochrome c oxidase complex. Mutations in MT-CO1 have been associated with Leber's hereditary optic neuropathy (LHON), acquired idiopathic sideroblastic anemia, Complex IV deficiency, colorectal cancer, sensorineural deafness, and recurrent myoglobinuria. Structure One of 37 mitochondrial genes, the ''MT-CO1'' gene is located from nucleotide pairs 5904 to 7444 on the guanine-rich heavy (H) section of mtDNA. The gene product is a 57 kDa protein composed of 513 amino acids. Function Cytochrome c oxidase subunit I (CO1 or MT-CO1) is one of three mitochondrial DNA (mtDNA) encoded subunits (MT-CO1, MT-CO2, MT-CO3) of respiratory complex IV. Complex IV is the third and final enzyme of the electron ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cytochrome C Oxidase Subunit I
Cytochrome c oxidase I (COX1) also known as mitochondrially encoded cytochrome c oxidase I (MT-CO1) is a protein that in humans is encoded by the ''MT-CO1'' gene. In other eukaryotes, the gene is called ''COX1'', ''CO1'', or ''COI''. Cytochrome c oxidase I is the main subunit of the cytochrome c oxidase complex. Mutations in MT-CO1 have been associated with Leber's hereditary optic neuropathy (LHON), acquired idiopathic sideroblastic anemia, Complex IV deficiency, colorectal cancer, sensorineural deafness, and recurrent myoglobinuria. Structure One of 37 mitochondrial genes, the ''MT-CO1'' gene is located from nucleotide pairs 5904 to 7444 on the guanine-rich heavy (H) section of mtDNA. The gene product is a 57 kDa protein composed of 513 amino acids. Function Cytochrome c oxidase subunit I (CO1 or MT-CO1) is one of three mitochondrial DNA (mtDNA) encoded subunits (MT-CO1, MT-CO2, MT-CO3) of respiratory complex IV. Complex IV is the third and final enzyme of the electron ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MT-CO2
Cytochrome c oxidase subunit 2, also known as cytochrome c oxidase polypeptide II, is a protein that in humans is encoded by the MT-CO2 gene. Cytochrome c oxidase subunit II, abbreviated COXII, COX2, COII, or MT-CO2, is the second subunit of cytochrome c oxidase. It is also one of the three mitochondrial DNA (mtDNA) encoded subunits (MT-CO1, MT-CO2, MT-CO3) of respiratory complex IV. Structure The ''MT-CO2'' gene is located on the p arm of mitochondrial DNA at position 12 and it spans 683 base pairs. The ''MT-CO2'' gene produces a 25.6 kDa protein composed of 227 amino acids. MT-CO2 is a subunit of the enzyme Cytochrome c oxidase () (Complex IV), an oligomeric enzymatic complex of the mitochondrial respiratory chain involved in the transfer of electrons from cytochrome c to oxygen. In eukaryotes this enzyme complex is located in the mitochondrial inner membrane; in aerobic prokaryotes it is found in the plasma membrane. The enzyme complex consists of 3-4 subunits ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cytochrome C Oxidase Subunit II
Cytochrome c oxidase subunit 2, also known as cytochrome c oxidase polypeptide II, is a protein that in humans is encoded by the MT-CO2 gene. Cytochrome c oxidase subunit II, abbreviated COXII, COX2, COII, or MT-CO2, is the second subunit of cytochrome c oxidase. It is also one of the three mitochondrial DNA (mtDNA) encoded subunits (MT-CO1, MT-CO2, MT-CO3) of respiratory complex IV. Structure The ''MT-CO2'' gene is located on the p arm of mitochondrial DNA at position 12 and it spans 683 base pairs. The ''MT-CO2'' gene produces a 25.6 kDa protein composed of 227 amino acids. MT-CO2 is a subunit of the enzyme Cytochrome c oxidase () (Complex IV), an oligomeric enzymatic complex of the mitochondrial respiratory chain involved in the transfer of electrons from cytochrome c to oxygen. In eukaryotes this enzyme complex is located in the mitochondrial inner membrane; in aerobic prokaryotes it is found in the plasma membrane. The enzyme complex consists of 3-4 su ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mitochondrial DNA
Mitochondrial DNA (mtDNA or mDNA) is the DNA located in mitochondria, cellular organelles within eukaryotic cells that convert chemical energy from food into a form that cells can use, such as adenosine triphosphate (ATP). Mitochondrial DNA is only a small portion of the DNA in a eukaryotic cell; most of the DNA can be found in the cell nucleus and, in plants and algae, also in plastids such as chloroplasts. Human mitochondrial DNA was the first significant part of the human genome to be sequenced. This sequencing revealed that the human mtDNA includes 16,569 base pairs and encodes 13 proteins. Since animal mtDNA evolves faster than nuclear genetic markers, it represents a mainstay of phylogenetics and evolutionary biology. It also permits an examination of the relatedness of populations, and so has become important in anthropology and biogeography. Origin Nuclear and mitochondrial DNA are thought to be of separate evolutionary origin, with the mtDNA being derived ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Muscle Weakness
Muscle weakness is a lack of muscle strength. Its causes are many and can be divided into conditions that have either true or perceived muscle weakness. True muscle weakness is a primary symptom of a variety of skeletal muscle diseases, including muscular dystrophy and inflammatory myopathy. It occurs in neuromuscular junction disorders, such as myasthenia gravis. Muscle weakness can also be caused by low levels of potassium and other electrolytes within muscle cells. It can be temporary or long-lasting (from seconds or minutes to months or years). The term myasthenia is from my- from Greek μυο meaning "muscle" + -asthenia ἀσθένεια meaning "weakness". Types Neuromuscular fatigue can be classified as either "central" or "peripheral" depending on its cause. Central muscle fatigue manifests as an overall sense of energy deprivation, while peripheral muscle fatigue manifests as a local, muscle-specific inability to do work. Neuromuscular fatigue Nerves control the con ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hypotonia
Hypotonia is a state of low muscle tone (the amount of tension or resistance to stretch in a muscle), often involving reduced muscle strength. Hypotonia is not a specific medical disorder, but a potential manifestation of many different diseases and disorders that affect motor nerve control by the brain or muscle strength. Hypotonia is a lack of resistance to passive movement, whereas muscle weakness results in impaired active movement. Central hypotonia originates from the central nervous system, while peripheral hypotonia is related to problems within the spinal cord, peripheral nerves and/or skeletal muscles. Severe hypotonia in infancy is commonly known as floppy baby syndrome. Recognizing hypotonia, even in early infancy, is usually relatively straightforward, but diagnosing the underlying cause can be difficult and often unsuccessful. The long-term effects of hypotonia on a child's development and later life depend primarily on the severity of the muscle weakness and the na ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Exercise Intolerance
Exercise intolerance is a condition of inability or decreased ability to perform physical exercise at the normally expected level or duration for people of that age, size, sex, and muscle mass. It also includes experiences of unusually severe post-exercise pain, fatigue, nausea, vomiting or other negative effects. Exercise intolerance is not a disease or syndrome in and of itself, but can result from various disorders. In most cases, the specific reason that exercise is not tolerated is of considerable significance when trying to isolate the cause down to a specific disease. Dysfunctions involving the pulmonary, cardiovascular or neuromuscular systems have been frequently found to be associated with exercise intolerance, with behavioural causes also playing a part. Signs and symptoms Exercise in this context means physical activity, not specifically exercise in a fitness program. For example, a person with exercise intolerance after a heart attack may not be able to sustain the a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hepatomegaly
Hepatomegaly is the condition of having an enlarged liver. It is a non-specific medical sign having many causes, which can broadly be broken down into infection, hepatic tumours, or metabolic disorder. Often, hepatomegaly will present as an abdominal mass. Depending on the cause, it may sometimes present along with jaundice. Signs and symptoms The individual may experience many symptoms, including weight loss, poor appetite and lethargy (jaundice and bruising may also be present). Causes Among the causes of hepatomegaly are the following: Infective Mechanism The mechanism of hepatomegaly consists of vascular swelling, inflammation (due to the various causes that are infectious in origin) and deposition of (1) non-hepatic cells or (2) increased cell contents (such due to iron in hemochromatosis or hemosiderosis and fat in fatty liver disease). Diagnosis Suspicion of hepatomegaly indicates a thorough medical history and physical examination, wherein the latter typically incl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hypertrophic Cardiomyopathy
Hypertrophic cardiomyopathy (HCM, or HOCM when obstructive) is a condition in which the heart becomes thickened without an obvious cause. The parts of the heart most commonly affected are the interventricular septum and the ventricles. This results in the heart being less able to pump blood effectively and also may cause electrical conduction problems. People who have HCM may have a range of symptoms. People may be asymptomatic, or may have fatigue, leg swelling, and shortness of breath. It may also result in chest pain or fainting. Symptoms may be worse when the person is dehydrated. Complications may include heart failure, an irregular heartbeat, and sudden cardiac death. HCM is most commonly inherited from a person's parents in an autosomal dominant pattern. It is often due to mutations in certain genes involved with making heart muscle proteins. Other inherited causes of left ventricular hypertrophy may include Fabry disease, Friedreich's ataxia, and certain medica ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
