Different morphologies of membranous structures induced by low pH.

<p>TEM images from cells exposed to external low pH (A to E, bar size = 200 nm). (F) Schematic representation of membranous structures of different morphologies: plasma membrane buds (a), tubules (b), vesicles connected to the plasma membrane (c), clusters of membrane vesicles (d) and inward protrusions of the plasma membrane with buds and connected vesicles (e). Ex – Extracellular space.