Mutants in a yeast Ran binding protein are defective in nuclear transport.

Schlenstedt, Gabriel; Wong, David G.; Koepp, Deanna M.; Silver, Pamela A.

doi:10.1002/j.1460-2075.1995.tb00221.x

Cited by 140 publications

(168 citation statements)

References 66 publications

(89 reference statements)

Supporting

Mentioning

159

Contrasting

Order By: Relevance

“…Ras-like GTPases regulate a variety of cellular events by acting as molecular switches; Ras-GTP is the active form and Ras-GDP is inactive (41). Ran mutants that bind, but are unable to hydrolyze, GTP have a dominant negative effect on Ran-dependent pathways, indicating that cycling between the GTP and GDP forms is important for Ran function (24,27,38). Similar phenomena are seen with GTPases involved in vesicular traffic, indicating that they may have similar mechanisms of action (42).…”

Section: Discussionmentioning

confidence: 99%

“…RanBP1 is required for nuclear protein import and RNA export in vivo (24). In permeabilized cells, RanBP1 stimulates nuclear protein import and inhibits the temperature-dependent release of docked receptor complex from the pore (25).…”

Section: Binding Domains For Ran-gtp and Ran-gdp/ranbp1mentioning

confidence: 99%

“…RanBP2 binds both p97 and Ran-GTP (11,(21)(22)(23) and has been proposed to be the initial docking site for the receptor complex on the pore and the site of GTP hydrolysis during transport (23). RanBP1 localizes to the cytoplasm, is essential for protein import in yeast (24), and stimulates protein import in a permeabilized cell assay (25). In solution, RanBP1 co-activates Ran-GTPase through an interaction with Ran-GTP and Ran-GAP1 (26 -28) and inhibits GTP dissociation from Ran-GTP (26).…”

mentioning

confidence: 99%

See 2 more Smart Citations

Different Binding Domains for Ran-GTP and Ran-GDP/RanBP1 on Nuclear Import Factor p97

Neil¹,

Adam

1997

Journal of Biological Chemistry

102

View full text Add to dashboard Cite

Several proteins are required for the transport of nuclear proteins from the cytoplasm to the nucleus, including the nuclear location sequence receptor (NLS receptor), p97, the small nuclear GTPase Ran/TC4, and several nucleoporins. The interaction of Ran with p97 is thought to regulate the interaction of these transport components. Ran-GTP alone binds p97, but Ran-GDP binds p97 only in conjunction with RanBP1. Using sitedirected mutagenesis and deletion analysis, we have identified two distinct but overlapping binding domains for Ran-GTP and Ran-GDP/RanBP1 on p97. A short acidic sequence in p97 is part of the Ran-GDP/RanBP1 binding domain, possibly functioning in a similar manner as the C-terminal acidic sequence in Ran. A conserved cysteine residue in p97, Cys-158, is required for binding Ran-GDP/RanBP1, but not for binding of Ran-GTP to p97. In a permeabilized cell protein import assay, a mutant p97 with alanine substituted for Cys-158 is unable to support import in the presence of NLS receptor and Ran. These results support a direct active role for Ran-GDP in the receptor complex and provide evidence that the activity of downstream effectors of small GTPases may be regulated by both GTP-and GDPbound forms of the protein.The transport of karyophilic proteins from the cytoplasm to the nucleus involves multiple steps and several protein factors. Proteins destined for the nucleus associate with the nuclear import machinery via short basic peptide sequences termed nuclear localization sequences or NLSs 1 (1). The NLS is recognized by a specific NLS-binding protein in the cytoplasm, the NLS receptor, also known as importin ␣/karyopherin ␣/PTAC58 (2-5). The NLS receptor and karyophile then bind to the nuclear pore via a second factor p97/importin ␤/karyopherin ␤/PTAC90 (6 -9). p97 mediates interaction with the pore by direct association with a subset of a peptide repeat-containing family of nuclear pore complex proteins (nucleoporins) (10 -12). Subsequent translocation of the receptor complex through the pore requires the action of the small nuclear GTPase Ran/ TC4 and GTP hydrolysis (13,14). Like other small GTPases, Ran requires a GTPase-activating protein Ran-GAP1, which is localized to the cytoplasm and a nuclear guanine nucleotide exchange factor, RCC1 (15-18).Several other Ran-binding proteins have been identified that are important for Ran function in protein import. The Ran-GTP binding proteins RanBP1 and RanBP2 were identified on overlay blots as specifically binding the GTP form of Ran (19,20). RanBP2/Nup358 is a nucleoporin that localizes to filaments extending from the cytoplasmic surface of the pore (21, 22). RanBP2 binds both p97 and Ran-GTP (11, 21-23) and has been proposed to be the initial docking site for the receptor complex on the pore and the site of GTP hydrolysis during transport (23). RanBP1 localizes to the cytoplasm, is essential for protein import in yeast (24), and stimulates protein import in a permeabilized cell assay (25). In solution, RanBP1 co-activates Ran-GTPase through an interac...

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Binding Domains For Ran-gtp and Ran-gdp/ranbp1mentioning

confidence: 99%

mentioning

confidence: 99%

See 1 more Smart Citation

Different Binding Domains for Ran-GTP and Ran-GDP/RanBP1 on Nuclear Import Factor p97

Neil¹,

Adam

1997

Journal of Biological Chemistry

102

View full text Add to dashboard Cite

show abstract

“…Furthermore, several other Ran-GTP binding proteins have been characterized [82]. The 23 kDa protein RanBP1/Yrblp binds Ran only in its GTP-form [54,55,[83][84][85][86] and acts as a co-activator of the Ran GTPase [55,84]. It shares a domain of 120 150 amino acids, the 'Ran binding domain', with other proteins, some of which are nucleoporins (discussed above).…”

Section: Other Factorsmentioning

confidence: 99%

“…The 70-residue core region of the Ran binding domain is highly conserved. Mutations therein disrupt the interaction with Ran [55,85]. A Ran mutant lacking the 6 carboxy-terminal amino acids was unable to bind to RanBP1 but still associated with NR]3.…”

Section: Other Factorsmentioning

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

Distinct nuclear import and export pathways mediated by members of the karyopherin β family

Moroianu

1998

J. Cell. Biochem.

View full text Add to dashboard Cite

Transport of proteins into and out of the nucleus occurs through nuclear pore complexes (NPCs) and is mediated by the interaction of transport factors with nucleoporins at the NPC. Nuclear import of proteins containing classical nuclear localization signals (NLSs) is mediated by a heterodimeric protein complex, composed of karyopherin alpha and beta1, that docks via beta1 the NLS-protein to the NPC. The GTPase Ran; the RanGDP binding protein, p10; and the RanGTP binding protein, RanBP1 are involved in translocation of the docked NLS-protein into the nucleus. Recently, new distinct nuclear import and export pathways that are mediated by members of the karyopherin beta family have been discovered. Karyopherin beta2 mediates import of mRNA binding proteins, whereas karyopherin beta3 and beta4 mediate import of a set of ribosomal proteins. Two other beta karyopherin family members, CRM1 and CAS, mediate export of proteins containing leucine-rich nuclear export signals (NES) and reexport of karyopherin alpha, respectively. This growing family contains new members that constitute potential transport factors for cargoes yet to be identified in the future. The common features of the members of karyopherin beta family are the ability to bind RanGTP and the ability to interact directly with nucleoporins at the NPC. The challenge for the future will be to identify the distinct or, perhaps, overlapping cargo(es) for each member of the karyopherin beta superfamily and to characterize the molecular mechanisms of translocation of karyopherins together with their cargoes through the NPC.

show abstract

Mutants in a yeast Ran binding protein are defective in nuclear transport.

Cited by 140 publications

References 66 publications

Different Binding Domains for Ran-GTP and Ran-GDP/RanBP1 on Nuclear Import Factor p97

Different Binding Domains for Ran-GTP and Ran-GDP/RanBP1 on Nuclear Import Factor p97

Protein import into the nucleus

Distinct nuclear import and export pathways mediated by members of the karyopherin β family

Contact Info

Product

Resources

About