A schematic of CRACR2a–dynein–mediated endocytosis during T cell activation. Activation of a T cell by an antigen presenting cell causes increase of intracellular calcium, which promotes the formation of CRACR2a cortical puncta at the IS. Activation of dynein–dynactin by CRACR2a facilitates the detachment of the cortical puncta from the actin cortex and initiates microtubule minus-end–directed transport.