1,440 articles
Mitochondrial fission
Mitochondrial fission, division of a mitochondrion into daughters, is driven by the Drp1/DNM1L GTPase with OMM receptors Mff, MiD49/51 and Fis1 at ER contact sites; distinct from fusion and from Drp1-independent fission pathways.
Mitochondrial fusion
Mitochondrial fusion, the merging of two mitochondria via MFN1/MFN2 (outer membrane) and OPA1 (inner membrane) GTPases, enables content mixing, mtDNA maintenance, quality control, and is disrupted in optic atrophy and CMT2A.
Mitochondrial Genes
Mitochondrial genes are genes on mitochondrial DNA (mtDNA), the maternally inherited, non-recombining, fast-mutating genome of mitochondria; in humans they encode 13 OXPHOS subunits, 2 rRNAs, and 22 tRNAs.
Mitochondrial import inner membrane translocase subunit TIM22
TIM22 (TIMM22) is the voltage-gated pore-forming core subunit of the mitochondrial inner membrane TIM22 carrier translocase, homologous to Tim17/Tim23, which inserts multispanning metabolite carriers and related proteins into the inner membrane using the membrane potential.
Mitochondrial import receptor subunit Tom22
Tom22 (TOM22_YEAST, P49334), the central receptor subunit of the mitochondrial TOM import complex; binds preproteins on both membrane sides, stabilizes the Tom40 pore dimer, and is conserved across all eukaryotes.
Mitochondrial import receptor subunit Tom6
Tom6 (TOMM6, TOM6) is a small single-pass α-helical subunit of the mitochondrial TOM protein-import complex that stabilizes Tom40, promotes tetramerization, and is conserved in opisthokonts and plants.
Mitochondrial inner membrane i-AAA protease complex subunit Mgr1
Mgr1 (YCL044C), also Mgr1p, is a Saccharomyces cerevisiae mitochondrial inner membrane adaptor subunit of the Yme1 i-AAA protease complex, required for full protease activity, substrate binding, and growth without mtDNA.
Mitochondrial inner membrane translocase complex, subunit Tim23
Tim23 (human gene TIMM23) is a core subunit of the TIM23 presequence translocase of the mitochondrial inner membrane, essential for importing presequence-containing proteins; a 2023 structure showed Tim17 forms the channel instead.
Mitochondrial Membrane Potential
Mitochondrial membrane potential (ΔΨm) is the voltage across the inner mitochondrial membrane generated by proton pumping at respiratory complexes I, III, and IV. Measured with cationic dyes TMRM, TMRE, rhodamine 123, and JC-1 following the Nernst equation; reports respiratory chain activity and apoptosis.
Mitochondrial myopathy
Mitochondrial myopathy: muscle disease from primary respiratory chain dysfunction, causing fatigue, weakness, exercise intolerance, often PEO; mtDNA or nuclear genes, heteroplasmy threshold, ragged-red fiber biopsy, supportive treatment.
Mitochondrial myopathy and sideroblastic anemia
Mitochondrial myopathy and sideroblastic anemia, also called myopathy, lactic acidosis, and sideroblastic anemia (MLASA), is a rare autosomal recessive mitochondrial disorder of muscle and bone marrow.
Mitochondrial neurogastrointestinal encephalomyopathy
Mitochondrial neurogastrointestinal encephalomyopathy (MNGIE) is an autosomal recessive disorder caused by TYMP gene mutations, first described in 1976, marked by digestive dysmotility and neurological decline.
Mitochondrial outer membrane translocase complex, subunit Tom5
Tom5, a ~50-amino-acid single-pass subunit of the mitochondrial TOM complex, links import receptors to the Tom40 general import pore via an acid chain and stabilizes the complex; nonessential in yeast, structurally resolved in the human TOM dimer.
Mitochondrial outer membrane translocase complex, subunit Tom70
Tom70, historically named MAS70 in yeast, is a receptor subunit of the TOM complex that recognizes hydrophobic mitochondrial precursor proteins, especially inner membrane metabolite carriers.
Mitochondrial outer membrane transport complex protein Metaxin 1/3
Metaxin 1/3 (IPR017410) is a protein family of mitochondrial outer membrane transport complex proteins, including human MTX1 (Metaxin-1, mitochondrial outer membrane import complex protein 1) and MTX3, SAM-complex components required for import and assembly of beta-barrel proteins such as Tom40 and VDAC.
Mitochondrial permeability transition pore
Mitochondrial permeability transition pore (mPTP, PTP): a high-conductance inner mitochondrial membrane channel passing solutes up to 1.5 kDa, opened by calcium overload, inhibited by cyclosporin A via cyclophilin D; its exact molecular composition remains debated.
Mitochondrial processing peptidase
Mitochondrial processing peptidase (MPP, EC 3.4.24.64) is a matrix metalloprotease heterodimer (α-MPP/β-MPP; PMPCA/PMPCB) that cleaves presequences from most mitochondrial precursor proteins, with MIP removing octapeptides in two-step maturation.
Mitochondrial protein import
Mitochondrial protein import: transport of nuclear-encoded proteins into mitochondria via TOM, TIM23, TIM22, SAM, and MIA translocases; over 99% of the roughly 1,500 human mitochondrial proteins are imported, driven by presequences, membrane potential, and the mtHsp70 motor.
Mitochondrial respirasome
The mitochondrial respirasome is a supercomplex of respiratory chain complexes I, III, and IV in the inner mitochondrial membrane, with a mass of about 1.7 megadaltons.
Mitochondrial ROS in stem-cell ageing
Mitochondrial ROS in stem-cell aging describes how reactive oxygen species from mitochondria act as dose-dependent signals controlling stem-cell fate, and how mitochondrial dysfunction drives stem-cell exhaustion with age.
Mitochondrial ROS production
Mitochondrial ROS production is the partial reduction of oxygen to superoxide and hydrogen peroxide at defined sites in the mitochondrial inner membrane, chiefly respiratory complexes I and III.
Mitochondrial targeting sequences and signals
Mitochondrial targeting sequences are amino acid segments within nuclear-encoded proteins that direct them to mitochondria and route them to one of at least five import routes.
Mitochondrial translation
Mitochondrial translation: protein synthesis by 55S mitoribosomes in the mitochondrial matrix, producing the 13 mtDNA-encoded OXPHOS inner membrane proteins via MTIF, TUFM, GFM1, MTRF1L factors.
Mitochondrial unfolded protein response (UPRmt)
UPRmt (mitochondrial unfolded protein response, mtUPR): conserved mitochondria-to-nucleus stress signaling triggered by misfolded mitochondrial proteins; first described in mammals in 2002; raises chaperone and protease expression via HSF1, ATF5, ESR1, and FOXO3 axes.
Mitophagy
Mitophagy is the selective autophagic degradation of damaged mitochondria by lysosomes, a quality-control mechanism conserved from yeast to humans whose PINK1–Parkin pathway is linked to early-onset Parkinson's disease.
Mitophagy decline in ageing
Mitophagy decline in aging is the age-related reduction of the selective autophagic removal of damaged mitochondria; the decline is tissue-selective, and interventions include urolithin A, NAD+ boosters, and exercise.
Mitosis
Mitosis: eukaryotic nuclear division producing two genetically identical daughter nuclei, staged as prophase through telophase, driven by the microtubule spindle and kinetochores, and safeguarded by the spindle assembly checkpoint; named by Walther Flemming from Greek mitos.
Mitotic motor proteins
Mitotic motor proteins are microtubule-based ATPases that generate the forces for spindle assembly and chromosome movement during cell division, with kinesin-5, CENP-E, chromokinesins, and dynein as the main actors.
Mitotic Prophase
Mitotic prophase is the first stage of M phase in mitosis, when duplicated chromosomes condense, the nucleolus disappears, spindle assembly begins, and it ends with nuclear envelope breakdown.
Mitsuo Ikebe
Mitsuo Ikebe (池部満雄) is a biochemist who studies the myosin molecular motor, known for light chain phosphorylation in smooth muscle and the 2002 Nature study of myosin-V's large step size.