Nutrient sensing refers to a cell’s ability to recognize and respond to fuel substrates such as glucose.
The cell requires an alternate pathway of utilization and accessory molecules such as enzymes and cofactors for each type of fuel it uses.
To conserve its resources a cell will only produce molecules that it needs at the time.
The level and type of fuel available to a cell determines the type of enzymes it needs to express from its genome for utilization.
Cell membrane’s surface receptors are designed to be activated in the presence of specific fuel molecules and communicates to the cell nucleus via a means of cascading interactions.
Nutrient receptors are receptors that are primarily designed to perform the function of nutrient sensing, making the cell is aware of the available nutrients and is able to produce only the molecules specific to that nutrient type.
A rapid and efficient response to disturbances in nutrient levels is crucial for the survival.
Cells have can sense nutrient concentrations and quickly regulate gene expression and protein modification to respond to any changes.
Cell growth is regulated by both extracellular nutrients and intracellular metabolite concentrations, in coordination?
AMP-activated kinase (AMPK) and mTOR complex serve as key molecules that sense cellular energy and nutrients levels, respectively.
There is an interplay among nutrients, metabolites, gene expression, and protein modification that are involved in the coordination of cell growth with extracellular and intracellular conditions.
Living cells use ATP as the most important direct energy source.
Hydrolysis of ATP to ADP and phosphate provides energy for most biological processes.
The ratio of ATP to ADP and AMP is a barometer of cellular energy status.
In eukaryotic cells, AMPK serves as a key cellular energy sensor and a master regulator of metabolism to maintain energy homeostasis.
Nutrient sensing and signaling is a key regulator of epigenetic activity in cancer.
During glucose shortage, the energy sensor AMPK activates arginine methyltransferase CARM1 and mediates histone H3 hypermethylation leading to enhanced autophagy.
Nutrient signaling directly targets epigenetic enzymes to control epigenetic modifications.
Nutrient sensing is a key regulator of tissue growth.
The main mediator of cellular nutrient sensing is the protein kinase TOR (target of rapamycin).
TOR receives information from levels of cellular amino acids and energy, and it regulates the activity of processes involved in cell growth, such as protein synthesis and autophagy.
Insulin-like signaling is the main mechanism of systemic nutrient sensing and mediates its growth-regulatory functions largely through the protein kinase pathway.
Other nutrition-regulated hormonal mechanisms contribute to growth control of modulating the activity of insulin-like signaling
Maintaining a careful balance between stored energy and caloric intake is important to ensure that the body has enough energy to maintain itself, grow, and engage in activity.
When balanced improperly, obesity and its accompanying disorders can result.