| mitochondrial inheritance | The inheritance of a trait encoded in the mitochondrial genome. Because of the oddities of mitochondria, mitochondrial inheritance does not obey the classic rules of genetics. Persons with a mitochondrial disease may be male or female but they are always related in the maternal line and no male with the disease can transmit it to his children. (12 Dec 1998) |
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| mitochondrial intermediate peptidase | <enzyme> Removes the octapeptide from the amino terminus of the intermediate protein processed from the protein precursor of certain mitochondrial proteins by the mitochondrial processing peptidase; smip from schizophyllum commune; rmip from rat; ymip from saccharomyces cerevisiae Registry number: EC 3.4.24.59 Synonym: mip peptidase, smip peptidase, rmip peptidase, ymip peptidase (26 Jun 1999) |
| mitochondrial matrix | The substance occupying the space enclosed by the inner membrane of a mitochondrion; it contains enzymes, filaments of DNA, ribosomes, granules, and inclusions of protein crystals, glycogen, and lipid. Synonym: mitochondrial matrix. (05 Mar 2000) |
| mitochondrial membrane | The double biomembrane surrounding the mitochondrion. (05 Mar 2000) |
| mitochondrial myopathies | Diseases of the muscles characterised by morphologic changes in mitochondria and often associated with excessive lipid accumulation. Muscle biopsies reveal "the presence of overly abundant and large mitochondria (often containing abnormal inclusions and cristae) in many muscle fibres. The terms mitochondrial and lipid storage have been used interchangeably to designate these myopathies, since the enzymes essential for intramuscular lipid metabolism are contained in the mitochondria, and a defect in the latter results in an abnormal accumulation of lipid bodies in muscle fibres." often defects in various oxidative enzymes figure. One type of mitochondrial myopathy is called pleoconial with reference to "a remarkably large number (pleo-) of enlarged mitochondria in the biopsied muscle", another is "called megaconial with reference to giant (mega-) mitochondria in the muscle." (adams and victor: principles of neurology, 2d ed, p980-1) (12 Dec 1998) |
| mitochondrial oxidative damage endonuclease | <enzyme> An 8-oxog-specific DNA endonuclease from rat liver mitochondria; recognises and incises at 8-oxog and abasic acid sites in duplex DNA Registry number: EC 3.1.25.- Synonym: oxidative damage-specific endonuclease, mtode enzyme (26 Jun 1999) |
| mitochondrial sheath | The spirally arranged mitochondria in the middle piece of a spermatozoon; may control movement of the tail. (05 Mar 2000) |
| mitochondrial swelling | Increase in volume of mitochondria due to an influx of fluid; it occurs in hypotonic solutions due to osmotic pressure and in isotonic solutions as a result of altered permeability of the membranes of respiring mitochondria. (12 Dec 1998) |
| disease, mitochondrial | Mutations (changes) in the mitochondrial chromosome are responsible for a number of disorders including an eye disease (Leber's hereditary optic atrophy), a type of epilepsy (called MERRF which stands for Myoclonus Epilepsy with Ragged Red Fibres), and a cause of dementia (called MELAS for Mitochondrial Encephalopathy, Lactic Acidosis and Stroke-like episodes). All mitochondrial diseases were entirely enigmatic before it was discovered that they were due to mutations not in regular chromosomes but the mitochondrial chromosome. (12 Dec 1998) |
| DNA, mitochondrial | Double-stranded DNA of mitochondria. In eukaryotes, the mitochondrial genome is circular and codes for ribosomal rnas, transfer rnas, and about 10 proteins. (12 Dec 1998) |
| AMP-activated protein kinase kinase | <enzyme> An endogenous kinase kinase; reactivates the inactive form of AMP-activated protein kinase (AMP-pk); phosphorylates the 63-kD subunit of AMP-pk Registry number: EC 2.7.1.- Synonym: AMP-pk reactivator, hmg CoA reductase kinase kinase (26 Jun 1999) |
| calmodulin-dependent protein kinase IV kinase | <enzyme> Phosphorylates and activates cam-kinase iv; from brain Registry number: EC 2.7.10.- Synonym: cam-kinase iv kinase (26 Jun 1999) |
| MAPKAP kinase-2 reactivating kinase | <enzyme> A mapk-like enzyme; homologous to p42(mapk) and p44(mapk); activated by phosphorylation of serine/threonine and tyrosine residues Registry number: EC 2.7.1.- Synonym: mapkap kinase-2 rk (26 Jun 1999) |
| ribosomal protein S6 kinase kinase | <enzyme> Isolated from unfertilised xenopus eggs; a 41 kD enzyme that is associated, in vivo, with phosphorylation on threonine and tyrosine residues and, in vitro, with phosphorylation on serine as well Registry number: EC 2.7.1.- Synonym: rsk kinase (26 Jun 1999) |
| protein kinase B kinase | <enzyme> Phosphorylates and activates protein kinase b on threonine-308; requires phosphatidylinositol-3,4,5-trisphosphate Registry number: EC 2.7.10.- Synonym: upstream kinase, pkb kinase (26 Jun 1999) |