Page last updated: 2024-10-24

positive regulation of autophagy of mitochondrion in response to mitochondrial depolarization

Definition

Target type: biologicalprocess

Any process that activates or increases the frequency, rate or extent of autophagy of the mitochondrion in response to mitochondrial depolarization. [GO_REF:0000058, GOC:pad, GOC:PARL, GOC:TermGenie, PMID:22020285]

Mitochondrial depolarization, a loss of the electrochemical gradient across the mitochondrial membrane, triggers a complex cellular response aimed at restoring homeostasis and preventing cell death. This response often involves the activation of autophagy, a process that degrades and recycles cellular components, including damaged mitochondria. This specific type of autophagy, targeting mitochondria, is known as mitophagy.

Here's a detailed breakdown of the biological process of positive regulation of autophagy of mitochondria in response to mitochondrial depolarization:

1. **Sensing Mitochondrial Depolarization:** The cell employs various mechanisms to detect the loss of membrane potential in mitochondria. Key sensors include:
* **PTEN-induced putative kinase 1 (PINK1):** In healthy mitochondria, PINK1 is rapidly degraded. However, upon depolarization, PINK1 accumulates on the mitochondrial outer membrane.
* **Parkin:** This E3 ubiquitin ligase is normally found in the cytosol. PINK1 recruits Parkin to the depolarized mitochondria, where it begins ubiquitinating mitochondrial proteins.
* **Other Sensors:** Additionally, the cell may utilize other sensors like reactive oxygen species (ROS) and Ca2+ levels to detect mitochondrial dysfunction.

2. **Ubiquitination Cascade:** Parkin, activated by PINK1, attaches ubiquitin chains to various proteins on the mitochondrial outer membrane. This ubiquitination signal serves as a "flag" marking the damaged mitochondria for destruction.

3. **Recruitment of Autophagy Machinery:** The ubiquitinated mitochondria become targets for autophagy receptors, such as p62/SQSTM1 and NDP52. These receptors bind to both the ubiquitin chains on the mitochondria and to the autophagic machinery.

4. **Formation of Autophagosomes:** The autophagy machinery, including LC3 and Atg proteins, assembles around the targeted mitochondria, engulfing them within a double-membrane vesicle known as an autophagosome.

5. **Fusion with Lysosomes:** The autophagosome then fuses with lysosomes, acidic organelles containing hydrolytic enzymes. These enzymes degrade the engulfed mitochondria, breaking them down into their constituent parts.

6. **Recycling and Homeostasis:** The breakdown products of the mitochondria are released into the cytosol, providing essential building blocks for the cell. This process helps restore cellular homeostasis and prevents the accumulation of damaged mitochondria.

7. **Regulation and Feedback Mechanisms:** The process of mitophagy is tightly regulated by a complex interplay of signaling pathways and feedback mechanisms. For example, mTOR signaling can inhibit autophagy, while AMPK activation can promote it.

This intricate process ensures that the cell can selectively remove damaged mitochondria, preventing their accumulation and the release of harmful substances, ultimately contributing to cell survival.
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Proteins (2)

ProteinDefinitionTaxonomy
Hexokinase-2A hexokinase-2 that is encoded in the genome of human. [PRO:DNx, UniProtKB:P52789]Homo sapiens (human)
Lysosomal acid glucosylceramidaseA lysosomal acid glucosylceramidase that is encoded in the genome of human. [PRO:DNx, UniProtKB:P04062]Homo sapiens (human)

Compounds (42)

CompoundDefinitionClassesRoles
ambroxolAmbroxol: A metabolite of BROMHEXINE that stimulates mucociliary action and clears the air passages in the respiratory tract. It is usually administered as the hydrochloride.aromatic amine
benserazidebenserazide : A carbohydrazide that results from the formal condensation of the carboxy group of DL-serine with the primary amino group of 4-(hydrazinylmethyl)benzene-1,2,3-triol. An aromatic-L-amino-acid decarboxylase inhibitor (DOPA decarboxylase inhibitor) that does not enter the central nervous system, it is used as its hydrochloride salt as an adjunct to levodopa in the treatment of parkinsonism. By preventing the conversion of levodopa to dopamine in the periphery, it causes an increase in the amount of levodopa reaching the central nervous system and so reduces the required dose. Benserazide has no antiparkinson actions when given alone.

Benserazide: An inhibitor of DOPA DECARBOXYLASE that does not enter the central nervous system. It is often given with LEVODOPA in the treatment of parkinsonism to prevent the conversion of levodopa to dopamine in the periphery, thereby increasing the amount that reaches the central nervous system and reducing the required dose. It has no antiparkinson actions when given alone.
carbohydrazide;
catechols;
primary alcohol;
primary amino compound
antiparkinson drug;
dopaminergic agent;
EC 4.1.1.28 (aromatic-L-amino-acid decarboxylase) inhibitor
beta-glucono-1,5-lactonebeta-glucono-1,5-lactone: structure

D-glucono-1,5-lactone : An aldono-1,5-lactone obtained from D-gluconic acid.
aldono-1,5-lactone;
gluconolactone
animal metabolite;
mouse metabolite
1-deoxynojirimycin1-deoxy-nojirimycin: structure in first source

duvoglustat : An optically active form of 2-(hydroxymethyl)piperidine-3,4,5-triol having 2R,3R,4R,5S-configuration.
2-(hydroxymethyl)piperidine-3,4,5-triol;
piperidine alkaloid
anti-HIV agent;
anti-obesity agent;
bacterial metabolite;
EC 3.2.1.20 (alpha-glucosidase) inhibitor;
hepatoprotective agent;
hypoglycemic agent;
plant metabolite
miglustatmiglustat : A hydroxypiperidine that is deoxynojirimycin in which the amino hydrogen is replaced by a butyl group.

miglustat: a glucosylceramide synthase inhibitor
piperidines;
tertiary amino compound
anti-HIV agent;
EC 2.4.1.80 (ceramide glucosyltransferase) inhibitor
n-phenylphthalimideN-phenylphthalimide: structure given in first source
N-Benzylphthalimideisoindoles
1-(10h-phenothiazin-2-yl)ethanone1-(10H-phenothiazin-2-yl)ethanone: structure in first sourcephenothiazines
mor-14N-methyldeoxynojirimycin: glucosidase inhibitorhydroxypiperidine;
piperidine alkaloid;
tertiary amino compound
anti-HIV agent;
cardioprotective agent;
EC 3.2.1.20 (alpha-glucosidase) inhibitor;
plant metabolite
1,2,3,4-tetrahydroxy-nor-tropanecalystegine B(2): RN given for (2-endo,3-exo,4-endo)-isomer; structure in first source
homonojirimycinhomonojirimycin: inhibits alpha-glucosidase; RN given for (2R-(2alpha,3alpha,4beta,5alpha,6beta))-isomer; structure in first source
cyclophellitolcyclophellitol: structure given in first source; isolated from Phellinus sp.
calystegine a3calystegine A3: also inhibits beta-xylosidase; structure in first source
miglitolpiperidines
isofagominepiperidines
n-nonyl-1-deoxynojirimycinN-nonyldeoxynojirimycin : A hydroxypiperidine that is deoxynojirimycin (duvoglustat) in which the amino hydrogen is replaced by a nonyl group.hydroxypiperidine;
tertiary amino compound
antiviral agent;
EC 3.2.1.20 (alpha-glucosidase) inhibitor;
EC 3.2.1.45 (glucosylceramidase) inhibitor
1-(1-benzimidazolyl)-3-(1-cyclohex-3-enylmethoxy)-2-propanolbenzimidazoles
2-(2-phenylethylthio)-3-pyridinecarboxylic acidaromatic carboxylic acid;
pyridines
4-(2-furanylmethyl)-3-(phenylmethyl)-1H-1,2,4-triazole-5-thionebenzenes
2-[[4-(4-chloroanilino)-6-(1-pyrrolidinyl)-1,3,5-triazin-2-yl]amino]ethanoldialkylarylamine;
tertiary amino compound
4-(benzenesulfonamido)-N-(5-ethyl-1,3,4-thiadiazol-2-yl)benzamidesulfonamide
tamoxifenstilbenoid;
tertiary amino compound
angiogenesis inhibitor;
antineoplastic agent;
bone density conservation agent;
EC 1.2.3.1 (aldehyde oxidase) inhibitor;
EC 2.7.11.13 (protein kinase C) inhibitor;
estrogen antagonist;
estrogen receptor antagonist;
estrogen receptor modulator
4-oxido-3-(4-phenoxyphenyl)-4a,5,6,7,8,8a-hexahydroquinoxalin-1-ium 1-oxidearomatic ether
2-[[4-(3-methylanilino)-6-(1-pyrrolidinyl)-1,3,5-triazin-2-yl]amino]ethanoldialkylarylamine;
tertiary amino compound
N-(1-benzylpiperidin-4-yl)-2-(pyridin-3-yl)quinazolin-4-amineN-(1-benzylpiperidin-4-yl)-2-(pyridin-3-yl)quinazolin-4-amine : A member of the class of quinazolines that is quinazoline which is substituted by a pyridin-3-yl group and a (1-benzylpiperidin-4-yl)nitrilo group at positions 2 and 4, respectively.aromatic amine;
piperidines;
pyridines;
quinazolines;
secondary amino compound;
tertiary amino compound
N-[4-methyl-2-(4-morpholinyl)-6-quinolinyl]cyclohexanecarboxamideaminoquinoline
andrographolidecarbobicyclic compound;
gamma-lactone;
labdane diterpenoid;
primary alcohol;
secondary alcohol
anti-HIV agent;
anti-inflammatory drug;
antineoplastic agent;
metabolite
n-(5-adamantane-1-yl-methoxy-pentyl)deoxynojirimycin
ogt2378sinbaglustat: an antineopl agent; structure in first source
nnc 26-9100NNC 26-9100: structure in first sourceaminopyridine
2-[[4-[2-[(2-methylpropan-2-yl)oxy]anilino]-6-(1-pyrrolidinyl)-1,3,5-triazin-2-yl]amino]ethanolaromatic ether
2-[[4-(5-chloro-2-methoxyanilino)-6-(1-piperidinyl)-1,3,5-triazin-2-yl]amino]ethanolmethoxybenzenes;
substituted aniline
2-[[4-(4-methylanilino)-6-(1-pyrrolidinyl)-1,3,5-triazin-2-yl]amino]ethanoldialkylarylamine;
tertiary amino compound
2-[[4-(2-chloroanilino)-6-(1-pyrrolidinyl)-1,3,5-triazin-2-yl]amino]ethanoldialkylarylamine;
tertiary amino compound
2-[[4-(2-methoxyanilino)-6-(1-pyrrolidinyl)-1,3,5-triazin-2-yl]amino]ethanolmethoxybenzenes;
substituted aniline
2-[[4-(3-methoxyanilino)-6-(1-pyrrolidinyl)-1,3,5-triazin-2-yl]amino]ethanolmethoxybenzenes;
substituted aniline
2-[[4-(4-methoxyanilino)-6-(1-pyrrolidinyl)-1,3,5-triazin-2-yl]amino]ethanolmethoxybenzenes;
substituted aniline
2-[[4-(2-hydroxyethylamino)-6-(1-pyrrolidinyl)-1,3,5-triazin-2-yl]amino]phenoldialkylarylamine;
tertiary amino compound
2-[[4-(2-phenoxyanilino)-6-(1-pyrrolidinyl)-1,3,5-triazin-2-yl]amino]ethanolaromatic ether
2-[[4-(1-pyrrolidinyl)-6-[2-(trifluoromethoxy)anilino]-1,3,5-triazin-2-yl]amino]ethanolaromatic ether
2-[[4-(5-chloro-2-ethoxyanilino)-6-(1-pyrrolidinyl)-1,3,5-triazin-2-yl]amino]ethanolaromatic ether
2-[[4-(5-chloro-2-propan-2-yloxyanilino)-6-(1-pyrrolidinyl)-1,3,5-triazin-2-yl]amino]ethanolaromatic ether