Recombinant Saccharomyces cerevisiae Nucleoporin NUP145 (NUP145), partial

Functions as a component of the nuclear pore complex (NPC). NPC components, collectively referred to as nucleoporins (NUPs), can play the role of both NPC structural components and of docking or interaction partners for transiently associated nuclear transport factors. Active directional transport is assured by both, a Phe-Gly (FG) repeat affinity gradient for these transport factors across the NPC and a transport cofactor concentration gradient across the nuclear envelope (GSP1 and GSP2 GTPases associated predominantly with GTP in the nucleus, with GDP in the cytoplasm). NUP145 is autocatalytically cleaved in vivo in 2 polypeptides which assume different functions in the NPC. NUP145N as one of the FG repeat nucleoporins participates in karyopherin interactions and contains part of the autocatalytic cleavage activity. NUP145C as part of the NUP84 complex is involved in nuclear poly(A)+ RNA and tRNA export. It is also required for normal NPC distribution (probably through interactions with MLP1 and MLP2) and NPC assembly, as well as for normal nuclear envelope organization.