@article{11125,
  abstract     = {Although nuclear envelope (NE) assembly is known to require the GTPase Ran, the membrane fusion machinery involved is uncharacterized. NE assembly involves formation of a reticular network on chromatin, fusion of this network into a closed NE and subsequent expansion. Here we show that p97, an AAA-ATPase previously implicated in fusion of Golgi and transitional endoplasmic reticulum (ER) membranes together with the adaptor p47, has two discrete functions in NE assembly. Formation of a closed NE requires the p97–Ufd1–Npl4 complex, not previously implicated in membrane fusion. Subsequent NE growth involves a p97–p47 complex. This study provides the first insights into the molecular mechanisms and specificity of fusion events involved in NE formation.},
  author       = {HETZER, Martin W and Meyer, Hemmo H. and Walther, Tobias C. and Bilbao-Cortes, Daniel and Warren, Graham and Mattaj, Iain W.},
  issn         = {1476-4679},
  journal      = {Nature Cell Biology},
  keywords     = {Cell Biology},
  number       = {12},
  pages        = {1086--1091},
  publisher    = {Springer Nature},
  title        = {{Distinct AAA-ATPase p97 complexes function in discrete steps of nuclear assembly}},
  doi          = {10.1038/ncb1201-1086},
  volume       = {3},
  year         = {2001},
}

@article{11126,
  abstract     = {Nuclear import of the two uracil-rich small nuclear ribonucleoprotein (U snRNP) components U1A and U2B′′ is mediated by unusually long and complex nuclear localization signals (NLSs). Here we investigate nuclear import of U1A and U2B′′ in vitro and demonstrate that it occurs by an active, saturable process. Several lines of evidence suggest that import of the two proteins occurs by an import mechanism different to those characterized previously. No cross competition is seen with a variety of previously studied NLSs. In contrast to import mediated by members of the importin-β family of nucleocytoplasmic transport receptors, U1A/U2B′′ import is not inhibited by either nonhydrolyzable guanosine triphosphate (GTP) analogues or by a mutant of the GTPase Ran that is incapable of GTP hydrolysis. Adenosine triphosphate is capable of supporting U1A and U2B′′ import, whereas neither nonhydrolyzable adenosine triphosphate analogues nor GTP can do so. U1A and U2B′′ import in vitro does not require the addition of soluble cytosolic proteins, but a factor or factors required for U1A and U2B′′ import remains tightly associated with the nuclear fraction of conventionally permeabilized cells. This activity can be solubilized in the presence of elevated MgCl2. These data suggest that U1A and U2B′′ import into the nucleus occurs by a hitherto uncharacterized mechanism.},
  author       = {HETZER, Martin W and Mattaj, Iain W.},
  issn         = {1540-8140},
  journal      = {Journal of Cell Biology},
  keywords     = {Cell Biology},
  number       = {2},
  pages        = {293--304},
  publisher    = {Rockefeller University Press},
  title        = {{An Atp-dependent, Ran-independent mechanism for nuclear import of the U1a and U2b′′ spliceosome proteins}},
  doi          = {10.1083/jcb.148.2.293},
  volume       = {148},
  year         = {2000},
}

@article{11127,
  abstract     = {Nuclear formation in Xenopus egg extracts requires cytosol and is inhibited by GTPγS, indicating a requirement for GTPase activity. Nuclear envelope (NE) vesicle fusion is extensively inhibited by GTPγS and two mutant forms of the Ran GTPase, Q69L and T24N. Depletion of either Ran or RCC1, the exchange factor for Ran, from the assembly reaction also inhibits this step of NE formation. Ran depletion can be complemented by the addition of Ran loaded with either GTP or GDP but not with GTPγS. RCC1 depletion is only complemented by RCC1 itself or by RanGTP. Thus, generation of RanGTP by RCC1 and GTP hydrolysis by Ran are both required for the extensive membrane fusion events that lead to NE formation.},
  author       = {HETZER, Martin W and Bilbao-Cortés, Daniel and Walther, Tobias C and Gruss, Oliver J and Mattaj, Iain W},
  issn         = {1097-2765},
  journal      = {Molecular Cell},
  keywords     = {Cell Biology, Molecular Biology},
  number       = {6},
  pages        = {1013--1024},
  publisher    = {Elsevier},
  title        = {{GTP hydrolysis by Ran is required for nuclear envelope assembly}},
  doi          = {10.1016/s1097-2765(00)80266-x},
  volume       = {5},
  year         = {2000},
}