Domain

Ran-GTPase activating protein 1, C-terminal (IPR009109)

Short name: Ran_GTPase_activating_1_C

Domain relationships

None.

Description

Ran GTPase is a ubiquitous protein required for nuclear transport, spindle assembly, nuclear assembly and mitotic cell cycle regulation. RanGTPase activating protein 1 (RanGAP1) is one of several RanGTPase accessory proteins. During interphase, RanGAP1 is located in the cytoplasm, while during mitosis it becomes associated with the kinetochores [PMID: 12852855]. Cytoplasmic RanGAP1 is required for RanGTPase-directed nuclear transport. The activity of RanGAP1 requires the accessory protein RanBP1. RanBP1 facilitates RanGAP1 hydrolysis of Ran-GTP, both directly and by promoting the dissociation of Ran-GTP from transport receptors, which would otherwise block RanGAP1-mediated hydrolysis. RanGAP1 is thought to bind to the Switch 1 and Switch 2 regions of RanGTPase. The Switch 2 region can be buried in complexes with karyopherin-beta2, and requires the interaction with RanBP1 to permit RanGAP1 function. RanGAP1 can undergo SUMO (small ubiquitin-like modifier) modification, which targets RanGAP1 to RanBP2/Nup358 in the nuclear pore complex, and is required for association with the nuclear pore complex and for nuclear transport [PMID: 11853669]. The enzymes involved in SUMO modification are located on the filaments of the nuclear pore complex.

The RanGAP1 N-terminal domain is fairly well conserved between vertebrate and fungal proteins, but yeast does not contain the C-terminal domain. The C-terminal domain is SUMO-modified and required for the localisation of RanGAP1 at the nuclear pore complex. The structure of the C-terminal domain is multihelical, consisting of two curved alpha/alpha layers in a right-handed superhelix.

GO terms

Biological Process

GO:0007165 signal transduction

Molecular Function

GO:0005096 GTPase activator activity

Cellular Component

No terms assigned in this category.

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.
SUPERFAMILY
GENE3D
Pfam