Name: Hydrogen ions
Location: Cytoplasm
Description: Following internalization of virions within vesicles, the vesicles enter the endocytic pathway and are acidified as they move through the cell. The intravesicular pH decreases from 6.2 in early endosomes to approximately 5.0 by the time the terminal compartments of the pathway (lysosomes) are reached. Fusion of the membrane of enveloped viruses with the vesicle membrane is triggered as the pH drops; the time and location of penetration of different viruses are determined by the pH dependence of the fusion activity (Kunz et al., 2002).
References:
Kunz S, Borrow P, and Oldstone MBA. 2002. Receptor structure, binding, and cell entry of arenaviruses. In: MBA Oldstone (ed.), Arenaviruses I. The epidemiology, molecular and cell biology of arenaviruses, pp. 111-137. Springer-Verlag.