cellular response to acidic pH

Definition

Target type: biologicalprocess

Any process that results in a change in state or activity of a cell (in terms of movement, secretion, enzyme production, gene expression, etc.) as a result of a pH stimulus with pH < 7. pH is a measure of the acidity or basicity of an aqueous solution. [GOC:go_curators, GOC:mah, Wikipedia:PH]

Cellular response to acidic pH is a complex and multifaceted process that involves a coordinated effort of various cellular mechanisms to maintain intracellular pH homeostasis and protect against the damaging effects of acidification. When cells encounter an acidic environment, they activate a series of signaling pathways and molecular adaptations to cope with the challenge.

One key component of this response is the activation of proton pumps, such as the vacuolar H+-ATPase (V-ATPase) and the plasma membrane H+-ATPase (P-type H+-ATPase). These pumps actively transport protons out of the cell, helping to maintain a favorable intracellular pH.

Another important mechanism is the upregulation of proton exchangers, such as the sodium-proton exchanger (NHE) and the chloride-bicarbonate exchanger (AE). These exchangers facilitate the exchange of protons for other ions, effectively removing protons from the cytoplasm.

In addition to these transmembrane transport systems, cells can also employ intracellular buffering systems to mitigate the impact of acidification. These systems involve proteins and molecules that can bind to protons and neutralize their acidic effects. For instance, bicarbonate ions (HCO3-) act as an important intracellular buffer, while proteins like histidine residues in enzymes can also buffer protons.

Furthermore, cellular response to acidic pH often involves changes in gene expression. Acid stress can induce the expression of genes encoding proteins that enhance buffering capacity, proton transport, or stress response pathways. These changes in gene expression contribute to the long-term adaptation of cells to acidic environments.

Moreover, cells can activate autophagy, a process in which cellular components are degraded and recycled. Autophagy can help remove damaged organelles or proteins that may contribute to the acidic stress response.

In summary, cellular response to acidic pH involves a coordinated effort of multiple mechanisms, including proton pumps, exchangers, intracellular buffers, changes in gene expression, and autophagy, to maintain pH homeostasis and protect the cell from the damaging effects of acidification.'
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Proteins (4)

Compounds (117)