UniProt functional annotation for P32499



	UniProt functional annotation for P32499

UniProt code: P32499.

Organism: Saccharomyces cerevisiae (strain ATCC 204508 / S288c) (Baker's yeast).

Taxonomy: Eukaryota; Fungi; Dikarya; Ascomycota; Saccharomycotina; Saccharomycetes; Saccharomycetales; Saccharomycetaceae; Saccharomyces.

Function: 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). As one of the FG repeat nucleoporins NUP2 is involved in interactions with and guidance of nuclear transport receptors such as SRP1-KAP95 (importin alpha and beta) through the NPC. Like the closely related NUP1 it also plays an important role in disassembling and recycling SRP1-KAP95 to the cytoplasm after nuclear import. Upon entry of the heterotrimeric SRP1- KAP95-cargo complex in the nucleus, NUP2 binds through its N-terminus to the SRP1 nuclear localization signal (NLS) binding site, thus accelerating the release of the NLS-cargo. SRP1 in turn is released from NUP2 by binding of the GSP1-GTP associated export factor CSE1. NUP2 may also have a chromatin boundary/insulator activity through indirect interaction with genomic DNA via CSE1 and blocking of heterochromatin spreading. {ECO:0000269|PubMed:10684247, ECO:0000269|PubMed:11046143, ECO:0000269|PubMed:11387327, ECO:0000269|PubMed:11425876, ECO:0000269|PubMed:11535617, ECO:0000269|PubMed:11867631, ECO:0000269|PubMed:12062099, ECO:0000269|PubMed:12372823, ECO:0000269|PubMed:12543930, ECO:0000269|PubMed:12604785, ECO:0000269|PubMed:12917401, ECO:0000269|PubMed:14514698, ECO:0000269|PubMed:15039779}.

Subunit: Component of the nuclear pore complex (NPC). NPC constitutes the exclusive means of nucleocytoplasmic transport. NPCs allow the passive diffusion of ions and small molecules and the active, nuclear transport receptor-mediated bidirectional transport of macromolecules such as proteins, RNAs, ribonucleoparticles (RNPs), and ribosomal subunits across the nuclear envelope. Due to its 8-fold rotational symmetry, all subunits are present with 8 copies or multiples thereof. Binds to the nuclear basket of the NPC through NUP60 in a (GSP1, GSP2) GTPase-GTP-dependent manner. Interacts through its FG repeats with nuclear transport factors. Interacts with KAP122. {ECO:0000269|PubMed:10525531, ECO:0000269|PubMed:10684247, ECO:0000269|PubMed:11387327, ECO:0000269|PubMed:11535617, ECO:0000269|PubMed:12543930, ECO:0000269|PubMed:14514698, ECO:0000269|PubMed:14532109}.

Subcellular location: Nucleus, nuclear pore complex {ECO:0000269|PubMed:10684247}. Nucleus membrane; Peripheral membrane protein; Nucleoplasmic side.

Domain: Contains FG repeats. FG repeats are interaction sites for karyopherins (importins, exportins) and form probably an affinity gradient, guiding the transport proteins unidirectionally with their cargo through the NPC. FG repeat regions are highly flexible and lack ordered secondary structure. The overall conservation of FG repeats regarding exact sequence, spacing, and repeat unit length is limited. FG repeat types and their physico-chemical environment change across the NPC from the nucleoplasmic to the cytoplasmic side: FXFG repeats are especially abundant in NUPs on the nucleoplasmic side (in a highly charged environment and enriched in Ser and Thr).

Miscellaneous: Present with 2960 molecules/cell in log phase SD medium. {ECO:0000269|PubMed:14562106}.

Annotations taken from UniProtKB at the EBI.


Organism:		Saccharomyces cerevisiae (strain ATCC 204508 / S288c) (Baker's yeast).
Taxonomy:		Eukaryota; Fungi; Dikarya; Ascomycota; Saccharomycotina; Saccharomycetes; Saccharomycetales; Saccharomycetaceae; Saccharomyces.



Function:		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). As one of the FG repeat nucleoporins NUP2 is involved in interactions with and guidance of nuclear transport receptors such as SRP1-KAP95 (importin alpha and beta) through the NPC. Like the closely related NUP1 it also plays an important role in disassembling and recycling SRP1-KAP95 to the cytoplasm after nuclear import. Upon entry of the heterotrimeric SRP1- KAP95-cargo complex in the nucleus, NUP2 binds through its N-terminus to the SRP1 nuclear localization signal (NLS) binding site, thus accelerating the release of the NLS-cargo. SRP1 in turn is released from NUP2 by binding of the GSP1-GTP associated export factor CSE1. NUP2 may also have a chromatin boundary/insulator activity through indirect interaction with genomic DNA via CSE1 and blocking of heterochromatin spreading. {ECO:0000269\|PubMed:10684247, ECO:0000269\|PubMed:11046143, ECO:0000269\|PubMed:11387327, ECO:0000269\|PubMed:11425876, ECO:0000269\|PubMed:11535617, ECO:0000269\|PubMed:11867631, ECO:0000269\|PubMed:12062099, ECO:0000269\|PubMed:12372823, ECO:0000269\|PubMed:12543930, ECO:0000269\|PubMed:12604785, ECO:0000269\|PubMed:12917401, ECO:0000269\|PubMed:14514698, ECO:0000269\|PubMed:15039779}.


Subunit:		Component of the nuclear pore complex (NPC). NPC constitutes the exclusive means of nucleocytoplasmic transport. NPCs allow the passive diffusion of ions and small molecules and the active, nuclear transport receptor-mediated bidirectional transport of macromolecules such as proteins, RNAs, ribonucleoparticles (RNPs), and ribosomal subunits across the nuclear envelope. Due to its 8-fold rotational symmetry, all subunits are present with 8 copies or multiples thereof. Binds to the nuclear basket of the NPC through NUP60 in a (GSP1, GSP2) GTPase-GTP-dependent manner. Interacts through its FG repeats with nuclear transport factors. Interacts with KAP122. {ECO:0000269\|PubMed:10525531, ECO:0000269\|PubMed:10684247, ECO:0000269\|PubMed:11387327, ECO:0000269\|PubMed:11535617, ECO:0000269\|PubMed:12543930, ECO:0000269\|PubMed:14514698, ECO:0000269\|PubMed:14532109}.
Subcellular location:		Nucleus, nuclear pore complex {ECO:0000269\|PubMed:10684247}. Nucleus membrane; Peripheral membrane protein; Nucleoplasmic side.
Domain:		Contains FG repeats. FG repeats are interaction sites for karyopherins (importins, exportins) and form probably an affinity gradient, guiding the transport proteins unidirectionally with their cargo through the NPC. FG repeat regions are highly flexible and lack ordered secondary structure. The overall conservation of FG repeats regarding exact sequence, spacing, and repeat unit length is limited. FG repeat types and their physico-chemical environment change across the NPC from the nucleoplasmic to the cytoplasmic side: FXFG repeats are especially abundant in NUPs on the nucleoplasmic side (in a highly charged environment and enriched in Ser and Thr).
Miscellaneous:		Present with 2960 molecules/cell in log phase SD medium. {ECO:0000269\|PubMed:14562106}.