ABSTRACT
Over the past few years, the view of V-ATPases has changed
considerably. These proton pumps are no longer only considered
as important housekeeping enzymes required for regulation and
homeostasis of organelle pH, but have also emerged as important
players in cellular signaling. Indeed, V-ATPase assembly and,
consequently, enzymatic activity are tightly regulated in response
to environmental conditions. Recent evidence primarily from yeast,
and also from mammalian cells, indicates that V-ATPase assembly
is regulated by cytosolic pH. This suggests that V-ATPases are
potentially conserved pH sensors that couple cytosolic pH to the
luminal pH of vacuoles/lysosomes and link cellular physiology to
signal transduction.
