Human RanGTPase-activating protein RanGAP1 is a homologue of yeast Rna1p involved in mRNA processing and transport.

Bischoff, F. Ralf; Krebber, Heike; Kempf, Tore; Hermes, Ingrid; Ponstingl, Herwig

doi:10.1073/pnas.92.5.1749

Cited by 240 publications

(177 citation statements)

References 30 publications

Supporting

Mentioning

174

Contrasting

Unclassified

Order By: Relevance

“…If its primary function is in nuclear export, the cytoplasmic localization of Gle2p may seem paradoxical. However, similar observations have been reported for Rnalp, a GTPase-activating protein for Gsplp/Ran/TC4 transport activity (Bischoff et al, 1995;Corbett et al, 1995). Rnalp is localized both in the cytoplasm and at NPCs, and the rnal-l mutant has a rapid and penetrant poly(A)+ RNA export block (Hopper et al, 1990;Amberg et al, 1992;Koepp et al, 1996).…”

Section: Discussionmentioning

confidence: 71%

GLE2, a Saccharomyces cerevisiae homologue of the Schizosaccharomyces pombe export factor RAE1, is required for nuclear pore complex structure and function.

Murphy

Watkins

Wente

1996

MBoC

168

164

View full text Add to dashboard Cite

To identify and characterize novel factors required for nuclear transport, a genetic screen was conducted in the yeast Saccharomyces cerevisiae. Mutations that were lethal in combination with a null allele of the gene encoding the nucleoporin NuplOOp were isolated using a colony-sectoring assay. Three complementation groups of gle (for GLFG lethal) mutants were identified. In this report, the characterization of GLE2 is detailed. GLE2 encodes a 40.5-kDa polypeptide with striking similarity to that of Schizosaccharomyces pombe RAE1. In indirect immunofluorescence and nuclear pore complex fractionation experiments, Gle2p was associated with nuclear pore complexes. Mutated alleles of GLE2 displayed blockage of polyadenylated RNA export; however, nuclear protein import was not apparently diminished. Immunofluorescence and thin-section electron microscopic analysis revealed that the nuclear pore complex and nuclear envelope structure was grossly perturbed in gle2 mutants. Because the clusters of herniated pore complexes appeared subsequent to the export block, the structural perturbations were likely indirect consequences of the export phenotype. Interestingly, a two-hybrid interaction was detected between Gle2p and Srplp, the nuclear localization signal receptor, as well as Riplp, a nuclear export signal-interacting protein. We propose that Gle2p has a novel role in mediating nuclear transport.

show abstract

Section: Discussionmentioning

confidence: 71%

GLE2, a Saccharomyces cerevisiae homologue of the Schizosaccharomyces pombe export factor RAE1, is required for nuclear pore complex structure and function.

Murphy

Watkins

Wente

1996

MBoC

168

164

View full text Add to dashboard Cite

show abstract

“…Such pleiotropism is particularly pronounced in S. cerevisiae cells carrying temperature-sensitive mutations in the RNA1 gene which were first described by Hartwell (30) 3 decades ago. Only recently it was shown that Rna1p acts as a GAP for Gsp1p and participates in protein import into S. cerevisiae nuclei both in vitro and in vivo (20,31,32). The homologous protein from S. pombe, rna1p, possesses GAP activity for Gsp1p (31) and in contrast to S. cerevisiae Rna1p also stimulates the GTP hydrolysis mediated by human Ran (23,31).…”

mentioning

confidence: 99%

“…The GTP/GDP cycle is regulated by two auxiliary proteins, a GTPase activating protein (GAP) which stimulates the intrinsic GTPase activity of Ran by several orders of magnitude and a guanine nucleotide exchange factor which markedly accelerates the GTP for GDP exchange rate on Ran. The only guanine nucleotide exchange factor for Ran known to date is the nuclear protein RCC1, whereas the only RanGAP identified so far is a cytosolic protein (17)(18)(19)(20). The strictly compartmentalized organization of the two principle regulators, RanGAP and RCC1, indicates that Ran shuttles between the cytoplasm and the nucleus to interact with its regulator proteins and that a gradient of Ran⅐GTP exists across the nuclear envelope (for review see Refs.…”

mentioning

confidence: 99%

The Acidic C-terminal Domain of rna1p Is Required for the Binding of Ran·GTP and for RanGAP Activity

Haberland¹,

Becker²,

Gerke³

1997

Journal of Biological Chemistry

View full text Add to dashboard Cite

The small GTP binding protein Ran is an essential component of the nuclear protein import machinery whose GTPase cycle is regulated by the nuclear guanosine nucleotide exchange factor RCC1 and by the cytosolic GTPase activating protein RanGAP. In the yeasts Schizosaccharomyces pombe and Saccharomyces cerevisiae the RanGAP activity is encoded by the RNA1 genes which are essential for cell viability and nucleocytoplasmic transport in vivo. Although of limited sequence identity the two yeast proteins show a conserved structural organization characterized by an N-terminal domain of eight leucine-rich repeats, motifs implicated in protein-protein interactions, and a C-terminal domain rich in acidic amino acid residues. By analyzing the RanGAP activity of a series of recombinantly expressed rna1p mutant derivatives, we show that the highly acidic sequence in the C-terminal domain of both yeast proteins is indispensable for activating Ran-mediated GTP hydrolysis. Chemical cross-linking reveals that the same sequence in rna1p is required for rna1p⅐Ran complex formation indicating that the loss of GAP activity in the C-terminally truncated rna1p mutants results from an impaired interaction with Ran. The predominant species stabilized through the covalent cross-link is a rna1p⅐Ran heterodimer whose formation requires the GTP-bound conformation of Ran. As the acidic C-terminal domain of rna1p is required for establishing the interaction with Ran, the leucine-rich repeats domain in rna1p is potentially available for additional protein interactions perhaps required for directing a fraction of rna1p to the nuclear pore.The import of karyophilic proteins into the nucleus which occurs through the nuclear pore complex (NPC) 1 is an energydependent process specified by nuclear localization signals (NLSs) on the import substrate (for reviews see Refs. 1-4). Using digitonin-permeabilized HeLa cells as an in vitro transport system, it was shown that the import of substrate proteins is a multistep process depending on four cytosolic factors (5, 6) (for reviews see Refs. 7-10). Two of these factors form a heterodimeric complex serving as the NLS receptor. The smaller 60-kDa subunit of this complex, also known as importin ␣, is responsible for NLS binding, whereas the larger 97-kDa subunit, importin ␤, most likely mediates a targeting of the substrate-NLS receptor complex to the NPC. After docking the entire substrate-receptor complex is thought to travel through the NPC and then to dissociate close to or at the nucleoplasmic side of the pore (for review see Ref. 11). The two other factors identified in the in vitro transport system as essential components of the nuclear import machinery are the GTP-binding protein Ran/TC4 (herein referred to as Ran (12, 13)) and a small protein of 10 kDa, p10/NTF2. The latter can interact with NPC proteins, Ran, and importin ␤ and appears to be involved in the formation of a pentameric complex including p10, Ran in its GDP-bound form, the two NLS receptor subunits and a nuclear pore protein (14, 15).R...

show abstract

“…Like other Ras-like proteins, Ran has a low intrinsic GTPase activity. Hydrolysis of bound GTP is stimulated by a RanGAP [66] which was found to be a functional homologue of the cytoplasmic yeast protein Rnalp [63,67,68]. Mutants in RCC1 and its budding yeast homologue, PRP20, display pleiotropic defects.…”

Section: Ranmentioning

confidence: 99%

“…2). If RNA export is a mirror image of protein import, a second set of a nuclear GAP and a cytoplasmic GEF have to be postulated but they have not been found yet [67,68]. Using recombinant yeast proteins, it was shown that addition of GTP-loaded Gsplp (the essential yeast Ran), and not of Gsplp-GDP, caused dissociation of a complex consisting of FXFG repeats of Nuplp, NRct, and NR[3, as well as of a complex consisting of import substrate, NRct, and NRI3 [32].…”

Section: Ranmentioning

confidence: 99%

Protein import into the nucleus

Schlenstedt

1996

FEBS Letters

View full text Add to dashboard Cite

The transport of proteins from the cytoplasm into the nucleus is a multistep process. The nuclear localization sequence (NLS) of a transport substrate associates with the heterodimeric NLS-receptor which binds to a subset of proteins of the nuclear pore complex (NPC). Translocation through the NPC is energydependent and requires the small GTPase Ran. Proteins that interact with Ran in either the GDP-bound or the GTP-bound state coordinate transfer through the NPC. Lastly, the NLSreeeptorlsubstrate complex and Ran reach the nuclear side of the NPC where the complex disassembles.

show abstract

Human RanGTPase-activating protein RanGAP1 is a homologue of yeast Rna1p involved in mRNA processing and transport.

Cited by 240 publications

References 30 publications

GLE2, a Saccharomyces cerevisiae homologue of the Schizosaccharomyces pombe export factor RAE1, is required for nuclear pore complex structure and function.

GLE2, a Saccharomyces cerevisiae homologue of the Schizosaccharomyces pombe export factor RAE1, is required for nuclear pore complex structure and function.

The Acidic C-terminal Domain of rna1p Is Required for the Binding of Ran·GTP and for RanGAP Activity

Protein import into the nucleus

Contact Info

Product

Resources

About