phagosome acidification

Definition

Target type: biologicalprocess

Any process that reduces the pH of the phagosome, measured by the concentration of the hydrogen ion. [GOC:kmv, GOC:tb]

Phagosome acidification is a critical step in the innate immune response, enabling the destruction of engulfed pathogens. This process is initiated upon phagocytosis, where the cell engulfs the pathogen within a phagosome, a membrane-bound vesicle. Once formed, the phagosome undergoes a series of maturation steps, including acidification. This acidification is achieved through the coordinated action of proton pumps, primarily the vacuolar H+-ATPase (V-ATPase), and other transport proteins. The V-ATPase is a multi-subunit complex that utilizes the energy from ATP hydrolysis to pump protons from the cytoplasm into the phagosome lumen, lowering its pH. This acidification process serves several crucial functions: 1. It creates an acidic environment that is hostile to many pathogens, disrupting their survival and replication. 2. It activates hydrolytic enzymes, such as cathepsins, which are lysosomal proteases optimally active in acidic conditions, enabling the degradation of pathogen components. 3. It facilitates the fusion of the phagosome with lysosomes, organelles containing a diverse range of degradative enzymes, further enhancing pathogen destruction. 4. It promotes the recruitment and activation of other antimicrobial factors, such as reactive oxygen species (ROS) and antimicrobial peptides, contributing to a robust immune response. The precise regulation of phagosome acidification is essential for effective pathogen clearance and maintaining cellular homeostasis. Disruptions in this process can lead to impaired immune function and susceptibility to infections.'
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Proteins (1)

Compounds (3)