Proteins that form the nuclear pore barrier move like liquids

Nuclear pores control molecular traffic into and out of the cell nucleus. Measurements in living cells, together with molecular-dynamics simulations, show that flexible protein chains that form the selectivity barriers of nuclear pores are highly mobile, and that a sugar modification and the carrier protein importin-β help to preserve this dynamic state. The motion of the nuclear pore protein NUP98 is regulated by a transport receptor and a sugar modification.