Importins

Importins are proteins that interact with cargo proteins that are to be transported through the nuclear pore complex into the nucleus.  They provide the specificity that allows the cargo proteins to be transported through the nuclear pore.

Most of these proteins are part of the importinß/karyopherinß family.  This family also includes exportins.

Common features of importinß/karyopherinß family:

• Bind to nucleoporins
• Form complex with Ran GTPase in its GTP-bound form

Importins involved in classical nuclear transport include:

• Importin α
• Importin ß

In yeast, there are at least 10 importins, while there are probably twice as many importins present in mammalians (Macara 2001).

Back to Nuclear Import page