PMID- 10209022
OWN - NLM
STAT- MEDLINE
DCOM- 19990517
LR  - 20190508
IS  - 0021-9525 (Print)
IS  - 0021-9525 (Linking)
VI  - 145
IP  - 2
DP  - 1999 Apr 19
TI  - CRM1-mediated recycling of snurportin 1 to the cytoplasm.
PG  - 255-64
AB  - Importin beta is a major mediator of import into the cell nucleus. Importin beta 
      binds cargo molecules either directly or via two types of adapter molecules,
      importin alpha, for import of proteins with a classical nuclear localization
      signal (NLS), or snurportin 1, for import of m3G-capped U snRNPs. Both adapters
      have an NH2-terminal importin beta-binding domain for binding to, and import by, 
      importin beta, and both need to be returned to the cytoplasm after having
      delivered their cargoes to the nucleus. We have shown previously that CAS
      mediates export of importin alpha. Here we show that snurportin 1 is exported by 
      CRM1, the receptor for leucine-rich nuclear export signals (NESs). However, the
      interaction of CRM1 with snurportin 1 differs from that with previously
      characterized NESs. First, CRM1 binds snurportin 1 50-fold stronger than the Rev 
      protein and 5,000-fold stronger than the minimum Rev activation domain. Second,
      snurportin 1 interacts with CRM1 not through a short peptide but rather via a
      large domain that allows regulation of affinity. Strikingly, snurportin 1 has a
      low affinity for CRM1 when bound to its m3G-capped import substrate, and a high
      affinity when substrate-free. This mechanism appears crucial for productive
      import cycles as it can ensure that CRM1 only exports snurportin 1 that has
      already released its import substrate in the nucleus.
FAU - Paraskeva, E
AU  - Paraskeva E
AD  - Zentrum fur Molekulare Biologie der Universitat Heidelberg, D-69120 Heidelberg,
      Germany.
FAU - Izaurralde, E
AU  - Izaurralde E
FAU - Bischoff, F R
AU  - Bischoff FR
FAU - Huber, J
AU  - Huber J
FAU - Kutay, U
AU  - Kutay U
FAU - Hartmann, E
AU  - Hartmann E
FAU - Luhrmann, R
AU  - Luhrmann R
FAU - Gorlich, D
AU  - Gorlich D
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - United States
TA  - J Cell Biol
JT  - The Journal of cell biology
JID - 0375356
RN  - 0 (Carrier Proteins)
RN  - 0 (Karyopherins)
RN  - 0 (Nuclear Proteins)
RN  - 0 (RNA Cap-Binding Proteins)
RN  - 0 (Receptors, Cytoplasmic and Nuclear)
RN  - 0 (Recombinant Proteins)
RN  - 0 (Ribonucleoproteins, Small Nuclear)
RN  - 0 (SNUPN protein, human)
RN  - 0 (Transcription Factors)
RN  - 0 (exportin 1 protein)
SB  - IM
MH  - Animals
MH  - Binding Sites
MH  - Carrier Proteins/*metabolism
MH  - Cell Nucleus/metabolism
MH  - Chromatography, Affinity
MH  - Cytoplasm/metabolism
MH  - Escherichia coli
MH  - Female
MH  - HeLa Cells
MH  - Humans
MH  - Karyopherins
MH  - Kinetics
MH  - Models, Biological
MH  - Nuclear Proteins/isolation & purification/metabolism
MH  - Oocytes/physiology
MH  - RNA Cap-Binding Proteins
MH  - Receptors, Cytoplasmic and Nuclear/isolation & purification/*metabolism
MH  - Recombinant Proteins/isolation & purification/metabolism
MH  - Ribonucleoproteins, Small Nuclear/*metabolism
MH  - Signal Transduction
MH  - Transcription Factors/*metabolism
MH  - Xenopus laevis
PMC - PMC2133107
EDAT- 1999/04/20 00:00
MHDA- 1999/04/20 00:01
CRDT- 1999/04/20 00:00
PHST- 1999/04/20 00:00 [pubmed]
PHST- 1999/04/20 00:01 [medline]
PHST- 1999/04/20 00:00 [entrez]
AID - 10.1083/jcb.145.2.255 [doi]
PST - ppublish
SO  - J Cell Biol. 1999 Apr 19;145(2):255-64. doi: 10.1083/jcb.145.2.255.