late endosomal microautophagy
Definition
Target type: biologicalprocess
The autophagy process by which cytosolic proteins targeted for degradation are tagged with a chaperone and are directly transferred into and degraded in a late endosomal compartment. [GOC:autophagy, GOC:dph, GOC:pad, GOC:PARL, PMID:21238931]
Late endosomal microautophagy is a selective form of autophagy that occurs within the lumen of late endosomes. This process is distinct from canonical macroautophagy, which involves the formation of double-membrane vesicles called autophagosomes that engulf cytoplasmic material. In late endosomal microautophagy, the endosomal membrane invaginates, forming small vesicles that enclose portions of the endosomal lumen. These vesicles then pinch off, forming intraluminal vesicles (ILVs) within the endosome.
The selectivity of late endosomal microautophagy is determined by the presence of specific sorting signals on the cargo proteins destined for degradation. These signals can include ubiquitin tags, lysosomal targeting sequences, and other post-translational modifications. Once a cargo protein is recognized, it is transported to the endosomal membrane and incorporated into an invaginating vesicle.
The formation of ILVs in late endosomal microautophagy is driven by the ESCRT machinery, a complex set of proteins that are involved in membrane budding and vesicle formation. The ESCRT machinery is also involved in the sorting of proteins and lipids to the lysosome, a major organelle responsible for the degradation of cellular waste.
Late endosomal microautophagy plays an important role in the degradation of various cellular components, including misfolded proteins, damaged organelles, and receptor proteins. This process is essential for maintaining cellular homeostasis and protecting cells from stress.
The exact mechanism of late endosomal microautophagy is still being investigated, but it is thought to be regulated by a variety of factors, including the availability of nutrients, cellular stress levels, and the activity of signaling pathways. Further research is needed to fully elucidate the molecular mechanisms and physiological functions of this important cellular process.'
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Proteins (1)
| Protein | Definition | Taxonomy |
|---|---|---|
| Heat shock cognate 71 kDa protein | A heat shock cognate 71 kDa protein that is encoded in the genome of human. [PRO:DAN] | Homo sapiens (human) |
Compounds (9)
| Compound | Definition | Classes | Roles |
|---|---|---|---|
| adenosine diphosphate | Adenosine Diphosphate: Adenosine 5'-(trihydrogen diphosphate). An adenine nucleotide containing two phosphate groups esterified to the sugar moiety at the 5'-position. | adenosine 5'-phosphate; purine ribonucleoside 5'-diphosphate | fundamental metabolite; human metabolite |
| tubercidin | tubercidin : An N-glycosylpyrrolopyrimidine that is adenosine in which the in the 5-membered ring that is not attached to the ribose moiety is replaced by a carbon. Tubercidin is produced in the culture broth of Streptomyces tubericidus. Tubercidin: An antibiotic purine ribonucleoside that readily substitutes for adenosine in the biological system, but its incorporation into DNA and RNA has an inhibitory effect on the metabolism of these nucleic acids. | antibiotic antifungal agent; N-glycosylpyrrolopyrimidine; ribonucleoside | antimetabolite; antineoplastic agent; bacterial metabolite |
| toyocamycin | toyocamycin : An N-glycosylpyrrolopyrimidine that is tubercidin in which the hydrogen at position 5 of the pyrrolopyrimidine moiety has been replaced by a cyano group. Toyocamycin: 4-Amino-5-cyano-7-(D-ribofuranosyl)-7H- pyrrolo(2,3-d)pyrimidine. Antibiotic antimetabolite isolated from Streptomyces toyocaensis cultures. It is an analog of adenosine, blocks RNA synthesis and ribosome function, and is used mainly as a tool in biochemistry. | antibiotic antifungal agent; N-glycosylpyrrolopyrimidine; nitrile; ribonucleoside | antimetabolite; antineoplastic agent; apoptosis inducer; bacterial metabolite |
| nsc 65346 | sangivamycin : A nucleoside analogue that is adenosine in which the nitrogen at position 7 is replaced by a carbamoyl-substituted carbon. It is a potent inhibitor of protein kinase C. sangivamycin: RN given refers to parent cpd | nucleoside analogue | protein kinase inhibitor |
| adenosine | quinquefolan B: isolated from roots of Panax quinquefolium L.; RN not in Chemline 10/87; RN from Toxlit | adenosines; purines D-ribonucleoside | analgesic; anti-arrhythmia drug; fundamental metabolite; human metabolite; vasodilator agent |
| 8-aminoadenosine | |||
| 5'-deoxyadenosine | 5'-deoxyadenosine : A 5'-deoxyribonucleoside compound having adenosine as the nucleobase. 5'-deoxyadenosine: main heading DEOXYADENOSINE refers to the 3' cpd | 5'-deoxyribonucleoside; adenosines | Escherichia coli metabolite; human metabolite; mouse metabolite |
| ver 155008 | VER 155008: structure in first source | purine nucleoside | |
| nms-e973 | NMS-E973: structure in first source |