An enzyme that plays multiple roles in cellular energy homeostasis. AMP kinase activation stimulates hepatic fatty acid oxidation, ketogenesis, skeletal muscle fatty acid oxidation, and glucose uptake; inhibits cholesterol synthesis, lipogenesis, triglyceride synthesis, adipocyte lipolysis, and lipogenesis; and modulates insulin secretion by pancreatic beta-cells.

An intracellular degradation system involved in the disassembly and recycling of unnecessary or dysfunctional cellular components. Autophagy participates in cell death, a process known as autophagic dell death. Prolonged fasting is a robust initiator of autophagy and may help protect against cancer and even aging by reducing the burden of abnormal cells.

The relationship between autophagy and cancer is complex, however. Autophagy may prevent the survival of pre-malignant cells, but can also be hijacked as a malignant adaptation by cancer, providing a useful means to scavenge resources needed for further growth.

The aqueous component of the cytoplasm of a cell, within which various organelles and particles are suspended.

A type of organelle in the cells of eukaryotic organisms that forms as interconnected network of flattened, membrane-enclosed sacs or tube-like structures known as cisternae. Rough ER is studded with ribosomes and is the site of protein synthesis, whereas smooth ER functions in lipid manufacture and metabolism.

Any of a group of complex proteins or conjugated proteins that are produced by living cells and act as catalyst in specific biochemical reactions.

Macroautophagy is used primarily to eradicate damaged cell organelles or unused and/or damaged proteins. This involves the formation of a double membrane known as an autophagosome around the organelle marked for destruction before delivering it to a lysosome. Microautophagy, on the other hand, involves direct engulfment of cytoplasmic material by the lysosome via a process of invagination, meaning the inward folding of the lysosomal membrane.

An enzyme that participates in genetic pathways that sense amino acid concentrations and regulate cell growth, cell proliferation, cell motility, cell survival, protein synthesis, autophagy, and transcription. mTOR integrates other pathways including insulin, growth factors (such as IGF-1), and amino acids. It plays key roles in mammalian metabolism and physiology, with important roles in the function of tissues including liver, muscle, white and brown adipose tissue, and the brain. It is dysregulated in many human diseases, such as diabetes, obesity, depression, and certain cancers. mTOR has two subunits, mTORC1 and mTORC2. Also referred to as “mammalian” target of rapamycin.

Rapamycin, the drug for which this pathway is named (and the anti-aging properties of which are the subject of many studies), was discovered in the 1970s and is used as an immunosuppressant in organ donor recipients.

Tiny organelles inside cells that produce energy in the presence of oxygen. Mitochondria are referred to as the "powerhouses of the cell" because of their role in the production of ATP (adenosine triphosphate). Mitochondria are continuously undergoing a process of self-renewal known as mitophagy in order to repair damage that occurs during their energy-generating activities.

The selective degradation of mitochondria by autophagy. It often occurs in defective mitochondria following damage or stress. Mitophagy is key in keeping the cell healthy. It promotes turnover of mitochondria and prevents accumulation of dysfunctional mitochondria, which can lead to cellular degeneration.

A broad range of disorders caused by the progressive death of neurons in the central and peripheral nervous systems. Common neurodegenerative diseases include Alzheimer's disease, Parkinson's disease, Huntington’s disease, and multiple sclerosis. Although treatments are available for some neurodegenerative diseases, there are currently no cures.

A chemical reaction that removes an acetyl functional group from a chemical compound. The presence of the acetyl functional group plays an important role in the synthesis, stability and localization of about 85% of human proteins.^[1] During fasting, falling acetyl CoA levels in the cytosol initiate protein deacetylation and initiates autophagy. In general, protein deacetylation, whether from so-called caloric restriction mimetics or nutrient deprivation, is an important general inducer of autophagy.

Ubiquitin is a small regulatory protein found in most tissues of eukaryotic organisms (e.g. ubiquitously). Ubiquitination refers to the the process by which ubiquitin proteins are added to cytosolic proteins in order to: alter their cellular location, mark them for degradation via the proteasome, and promote or prevent protein interactions.