Life and health

Mitochondrial hypertrophic cardiomyopathy with lactic acidosis due to MTO1 deficiency

Mitochondrial hypertrophic cardiomyopathy with lactic acidosis due to MTO1 deficiency, also known as combined oxidative phosphorylation deficiency 10 (COXPD10), is a rare autosomal recessive mitochondrial disorder.

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 protease subunit 2

IMMP2L (UniProt Q96T52), the human mitochondrial inner membrane protease subunit 2, is a serine protease subunit of the IMP complex with IMMP1L, cleaving sorting signals from cytochrome c1 and GPD2; yeast ortholog Imp2; linked to Tourette syndrome.

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 membrane protein-associated neurodegeneration

MPAN (NBIA4) is an ultra-rare autosomal recessive neurodegenerative disorder caused by C19orf12 mutations, with brain iron accumulation, spasticity, dystonia, cognitive decline, and optic atrophy, onset usually in childhood.

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 myopathy with reversible cytochrome C oxidase deficiency

Mitochondrial myopathy with reversible cytochrome C oxidase deficiency, also called benign COX deficiency or reversible infantile respiratory chain deficiency (RIRCD), is a rare maternally inherited mitochondrial myopathy caused mainly by the homoplasmic MT-TE m.14674T>C mutation, causing severe infantile hypotonia and lactic acidosis with spontaneous recovery by age 2 to 3 years.

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 neurogastrointestinal encephalopathy syndrome

MNGIE syndrome, also called thymidine phosphorylase deficiency, is a rare autosomal recessive TYMP-related mitochondrial DNA depletion disease causing gastrointestinal dysmotility, cachexia, ophthalmoplegia, neuropathy, and leukoencephalopathy, with onset around age 18 and mean death at 37 years.

Mitochondrial outer membrane permeabilization

Mitochondrial outer membrane permeabilization (MOMP) is the crucial event in the intrinsic apoptosis pathway where the outer membrane becomes permeable, allowing soluble proteins to enter the cytosol.

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 pyruvate carrier

The mitochondrial pyruvate carrier (MPC), also called pyruvate translocase, is an MPC1/MPC2 heterodimer of the inner mitochondrial membrane that imports pyruvate with a proton into the matrix; identified in 2012, structurally solved in 2025, and targeted by UK5099.

Mitochondrial pyruvate carrier deficiency

Mitochondrial pyruvate carrier deficiency (MPYCD, OMIM 614741) is a rare autosomal recessive MPC1-related disorder causing neonatal lactic acidosis, elevated pyruvate with normal lactate/pyruvate ratio, encephalopathy, and developmental delay.

Sep 29, 2026

Mitochondrial replacement therapy

Mitochondrial replacement therapy is an IVF technique that replaces defective mitochondria in a mother's egg with donor mitochondria, preventing inherited mitochondrial disease; only the UK practices it.

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 Rho GTPase

Mitochondrial Rho GTPase (Miro; Miro1/Miro2, RHOT1/RHOT2) is an atypical outer mitochondrial membrane GTPase with two GTPase domains and EF-hands that links mitochondria to kinesin/dynein via TRAK adaptors, regulating transport, calcium arrest, mitophagy, and disease.

Mitochondrial ribosomal RNA genes

Mitochondrial ribosomal RNA genes (MT-RNR1, MT-RNR2) are the two mtDNA genes encoding 12S and 16S rRNAs of the 55S mitoribosome, transcribed as polycistronic RNA, processed by tRNA excision, chemically modified, and linked to mitochondrial disease.

Mitochondrial ribosome

Mitochondrial ribosome (mitoribosome): the protein-synthesis machine inside mitochondria, descended from an alpha-proteobacterial ribosome; RNA-reduced, protein-rich (human 55S: 80 proteins, 3 RNAs), specialized for membrane proteins and linked to mitochondrial disease.

Mitochondrial RNA polymerase

Mitochondrial RNA polymerase (POLRMT) is the single-subunit, nuclear-encoded enzyme of phage ancestry that transcribes the mitochondrial genome and, in mammals, supplies the RNA primers that launch mitochondrial DNA replication.