IPO13

Also known as IMP13, KAP13, LGL2, RANBP13, importin 13

Importin-13 is a protein encoded by the IPO13 gene in humans. Importin-13 is a member of the importin-β family of nuclear transport receptors (NTRs) and was first identified as a transport receptor in 2000. According to PSI-blast based secondary structure PREDiction (PSIPRED), importin-13 contains 38 α-helices. Importin-13 accommodates a range of cargoes due to its flexible superhelical structure and a cargo binding and release system that is distinct from other importin-like transport receptors. IPO13 is broadly expressed in a variety of tissues in the human body, including the heart, cornea,

Gene data

IPO13

Name: importin 13
Type: protein-coding
Position: 43,946,830–43,968,024 (+)
Aliases: IMP13, KAP13, LGL2, RANBP13
Ensembl: ENSG00000117408
RefSeq RNA: NM_014652.4, XM_024451069.2, XM_024451070.2, XM_054339738.1, XM_054339739.1
RefSeq protein: NP_055467.3, XP_024306837.1, XP_024306838.1, XP_054195713.1, XP_054195714.1

This gene encodes a member of the importin-beta family of nuclear transport proteins. The encoded protein mediates the import of specific cargo proteins from the cytoplasm to the nucleus and is dependent on the Ras-related nuclear protein-GTPase system. The encoded protein is also involved in nuclear export of the eukaryotic translation initiation factor 1A.[provided by RefSeq, Mar 2009].

Gene Ontology

Biological process

protein import into nucleus protein import into nucleus

Article

5 sections

Contents

Nucleocytoplasmic transport
Interactions
Function
References
Further reading

== Nucleocytoplasmic transport == In eukaryotic cells, macromolecules larger than ~40 kDa are actively transported between the nuclear and cytosolic compartment through nuclear pore complexes (NPCs) via soluble transport receptors. Importin-β-like factors are the largest class of NTRs and are classified as importins or exportins based on the direction of cargo transport and their response to the RanGTP gradient across the nuclear envelope. Importins load their cargoes in the cytoplasm in the absence of RanGTP and release their cargoes in the nucleus upon binding RanGTP. Exportins bind their cargoes in the nucleus in the presence of RanGTP and release their cargoes in the cytoplasm upon RanGTP hydrolysis. Unlike other importins, importin-13 is a versatile nuclear transport receptor with a bidirectional transport capacity, such that it mediates the nuclear import of certain cargoes and the nuclear export of other cargoes. Other nuclear transport receptors reported to facilitate both the nuclear import and export of macromolecules are exportin 5 (Msn5 in yeast) and exportin 4.