FIGURE 1.

CCT in the reorganization of actin and tubulin at the immune synapse. TCR activation promotes protein synthesis. The chaperone CCT accumulates in activated centrosomes, which then can act as folding centers for newly synthesized proteins. The new polypeptides are assisted in their folding by CCT, whose major obligate substrates are actin and tubulin. Actin is directly sorted into its native form, whereas tubulin needs the assistance of different tubulin-binding co-factors (TBCs) to form stable αβ-heterodimers. The newly formed building blocks are then ready to be incorporated into their respective filaments, F-actin and microtubules. CCT may localize to pre-existing actin filaments, where it can help in the folding of mRNAs that would then be bound to these filaments, creating local gradients of protein concentration. Organelles and cell components are not depicted to scale. Inset, CCT organization and ATP consumption.