Sandbox 148: Difference between revisions

Karyopherin beta 2 (kapβ2) is an importin that transports various cargo protein into the nucleus through interactions with nucleoporins,  which are proteins of the nucleopore complex (NPC). One might overlook the significance of this protein but actually plays a crucial role in the human body by mediating transport of RNA- binding proteins involved in transcription, RNA processing, RNA transport and translation. The structure of KAPβ is composed of 20 antiparallel helices called HEAT repeats. These <scene name='37/372748/Kapb2_rainbow_heat/2'>HEAT</scene> repeats contribute to kapβ2’s large <scene name='37/372748/Kapb2_rainbow_superhelical/1'>superhelical shape</scene>. That form two arches: one at the <scene name='37/372748/Kapb2_rainbow_nterminal/1'>N-terminal</scene> and the other at the <scene name='37/372748/Kapb2_rainbow_cterminal/1'>C-terminal</scene>. Through recognition of a nuclear localization signal (NLS) located on its cargo, kapβ2 binds to its cargo via its C-terminal arch. Release of the cargo is mediated by RanGTP, which once bound, modifies the shape of kapβ2.  Release of the cargo is mediated once contact occurs between RanGTP and N-terminal arch of Kapβ2.