Figure 1

Simple schema of metabolite-sensing. (A) The dynamic equilibrium between the polymeric forms of a cytoskeletal protein (red rectangles) depends on some enzymes (green pentagons and brown circles) binding and stabilizing the polymers when these enzymes are either active in catalyzing their cognate reactions (presence of star) or when these enzymes are inactive (absence of star). Only one type of cytoskeletal protein is shown. (B) The web of interactions involved in sensing changes in levels of metabolites by the cytoskeleton. The red arrows inside the ellipse represent the equilibrium between the polymeric forms that is at the heart of the sensing. The blue arrows represent the flow of information through the network following a change in metabolite levels. The thick blue arrow represents initial effects of changes in metabolite levels on the equilibrium between cytoskeletal structures with and without associated enzymes. Thin blue arrows represent subsequent effects on cytoskeletal dynamics, enzyme activation, enzyme-enzyme association and on ATP/GTP levels.