Across the great divide: the plant cell surface continuum

• Plant plasma membrane proteins are not randomly distributed within the lipid bilayer.
• Both cytoskeleton and cell wall regulate plasma membrane protein mobility and association.
• Membrane microdomains organize proteins into functional associations.
• Plasma membrane proteins have both signalling and enzymatic roles.
• Fluorescence Recovery After Photobleaching (FRAP) enables monitoring of membrane protein dynamics.

The plant cell wall, plasma membrane and cytoskeleton exist as a cell surface continuum. This interconnection of organelles forms the interface between the plant cell and the external environment and is important for detecting the presence of a diverse range of stimuli. A plethora of plasma membrane microdomains with putative roles in membrane localized enzymatic or signalling processes have been described. While regulation of cell wall composition is defined by proteins within the plasma membrane, the cell wall has been shown to have an anchoring role on plasma membrane proteins which affects their lateral mobility. This interplay between plasma membrane and cell wall components is necessary for plasma membrane microdomain function. Actin and microtubule cytoskeletons are also involved in maintenance and function of the cell surface continuum. Investigation of the interactions between organellar components of this mechanism are important if we are to understand how cells respond to external signals.