Caenorhabditis elegans nucleoporins Nup93 and Nup205 determine the limit of nuclear pore complex size exclusion in vivo.

Nuclear pore complexes (NPCs) span the nuclear envelope and mediate communication between the nucleus and the cytoplasm. To obtain insight into the structure and function of NPCs of multicellular organisms, we have initiated an extensive analysis of Caenorhabditis elegans nucleoporins. Of 20 assigned C. elegans nucleoporin genes, 17 were found to be essential for embryonic development either alone or in combination. In several cases, depletion of nucleoporins by RNAi caused severe defects in nuclear appearance. More specifically, the C. elegans homologs of vertebrate Nup93 and Nup205 were each found to be required for normal NPC distribution in the nuclear envelope in vivo. Depletion of Nup93 or Nup205 caused a failure in nuclear exclusion of nonnuclear macromolecules of approximately 70 kDa without preventing active nuclear protein import or the assembly of the nuclear envelope. The defects in NPC exclusion were accompanied by abnormal chromatin condensation and early embryonic arrest. Thus, the contribution to NPC structure of Nup93 and Nup205 is essential for establishment of normal NPC function and for cell viability.

[1]  K. Wilson,et al.  Transmission electron microscope studies of the nuclear envelope in Caenorhabditis elegans embryos. , 2002, Journal of structural biology.

[2]  S. Bagley,et al.  The nuclear pore complex. , 2000, Journal of cell science.

[3]  C. Feldherr,et al.  The permeability of the nuclear envelope in dividing and nondividing cell cultures , 1990, The Journal of cell biology.

[4]  N. Daigle,et al.  An evolutionarily conserved NPC subcomplex, which redistributes in part to kinetochores in mammalian cells , 2001, The Journal of cell biology.

[5]  E. Conti,et al.  Nucleocytoplasmic transport enters the atomic age. , 2001, Current opinion in cell biology.

[6]  I. Mattaj,et al.  Nucleocytoplasmic transport: the soluble phase. , 1998, Annual review of biochemistry.

[7]  J. Olivo-Marin,et al.  Nuclear architecture and spatial positioning help establish transcriptional states of telomeres in yeast , 2002, Nature Cell Biology.

[8]  Elizabeth Casey,et al.  Creation of low-copy integrated transgenic lines in Caenorhabditis elegans. , 2001, Genetics.

[9]  K. Wilson,et al.  Nuclear pore protein gp210 is essential for viability in HeLa cells and Caenorhabditis elegans. , 2003, Molecular biology of the cell.

[10]  B. Chait,et al.  The Yeast Nuclear Pore Complex: Composition, Architecture, and Transport Mechanism , 2000 .

[11]  M. Fornerod,et al.  The cytoplasmic filaments of the nuclear pore complex are dispensable for selective nuclear protein import , 2002, The Journal of cell biology.

[12]  Vincent Galy,et al.  Ran GTPase cycle and importins alpha and beta are essential for spindle formation and nuclear envelope assembly in living Caenorhabditis elegans embryos. , 2002, Molecular biology of the cell.

[13]  B. Fontoura,et al.  A Conserved Biogenesis Pathway for Nucleoporins: Proteolytic Processing of a 186-Kilodalton Precursor Generates Nup98 and the Novel Nucleoporin, Nup96 , 1999, The Journal of cell biology.

[14]  A. Fire,et al.  Two-color GFP expression system for C. elegans. , 1999, BioTechniques.

[15]  R. Jessberger.  The many functions of smc proteins in chromosome dynamics , 2002, Nature Reviews Molecular Cell Biology.

[16]  E. Zimmerman,et al.  Removal of a single pore subcomplex results in vertebrate nuclei devoid of nuclear pores. , 2003, Molecular cell.

[17]  M. Rieger,et al.  A Novel Complex of Nucleoporins, Which Includes Sec13p and a Sec13p Homolog, Is Essential for Normal Nuclear Pores , 1996, Cell.

[18]  C. Rollenhagen,et al.  Nup192p Is a Conserved Nucleoporin with a Preferential Location at the Inner Site of the Nuclear Membrane* , 1999, The Journal of Biological Chemistry.

[19]  P. Zipperlen,et al.  Roles for 147 embryonic lethal genes on C.elegans chromosome I identified by RNA interference and video microscopy , 2001, The EMBO journal.

[20]  E. Hurt,et al.  Yeast genetics to dissect the nuclear pore complex and nucleocytoplasmic trafficking. , 1997, Annual review of genetics.

[21]  Jan Ellenberg,et al.  Nuclear envelope breakdown in starfish oocytes proceeds by partial NPC disassembly followed by a rapidly spreading fenestration of nuclear membranes , 2003, The Journal of cell biology.

[22]  V. Reinke,et al.  A targeted RNAi screen for genes involved in chromosome morphogenesis and nuclear organization in the Caenorhabditis elegans germline. , 2002, Genetics.

[23]  M. Mann,et al.  Nup93, a vertebrate homologue of yeast Nic96p, forms a complex with a novel 205-kDa protein and is required for correct nuclear pore assembly. , 1997, Molecular biology of the cell.

[24]  U Aebi,et al.  The nuclear pore complex: from molecular architecture to functional dynamics. , 1999, Current opinion in cell biology.

[25]  Y. Dong,et al.  Systematic functional analysis of the Caenorhabditis elegans genome using RNAi , 2003, Nature.

[26]  W. Fischer,et al.  Identification of a new vertebrate nucleoporin, Nup188, with the use of a novel organelle trap assay. , 2000, Molecular biology of the cell.

[27]  F. Piano,et al.  Gene Clustering Based on RNAi Phenotypes of Ovary-Enriched Genes in C. elegans , 2002, Current Biology.

[28]  B. Chait,et al.  Proteomic analysis of the mammalian nuclear pore complex , 2002, The Journal of cell biology.

[29]  S. Strome,et al.  Spindle Dynamics and the Role of γ-Tubulin in Early Caenorhabditis elegans Embryos , 2001 .

[30]  S. Vasu,et al.  Nuclear pores and nuclear assembly. , 2001, Current opinion in cell biology.

[31]  D. Goldfarb,et al.  Yeast Nucleoporins Involved in Passive Nuclear Envelope Permeability , 2000, The Journal of cell biology.

[32]  G. Blobel,et al.  The yeast nucleoporin Nup188p interacts genetically and physically with the core structures of the nuclear pore complex , 1996, The Journal of cell biology.

[33]  K. Yokomori,et al.  A Human Condensin Complex Containing hCAP-C–hCAP-E and CNAP1, a Homolog of Xenopus XCAP-D2, Colocalizes with Phosphorylated Histone H3 during the Early Stage of Mitotic Chromosome Condensation , 2000, Molecular and Cellular Biology.

[34]  M. Fornerod,et al.  The nucleoporin Nup153 is required for nuclear pore basket formation, nuclear pore complex anchoring and import of a subset of nuclear proteins , 2001, The EMBO journal.

[35]  A. Fire,et al.  Specific interference by ingested dsRNA , 1998, Nature.

[36]  Ueli Aebi,et al.  Structure and Assembly of the Nup84p Complex , 2000, The Journal of cell biology.

[37]  G. Blobel,et al.  Nuclear pore complex contains a family of glycoproteins that includes p62: glycosylation through a previously unidentified cellular pathway. , 1987, Proceedings of the National Academy of Sciences of the United States of America.

[38]  E. Hurt,et al.  From nucleoporins to nuclear pore complexes. , 1997, Current opinion in cell biology.

[39]  M. Hetzer,et al.  The Conserved Nup107-160 Complex Is Critical for Nuclear Pore Complex Assembly , 2003, Cell.

[40]  G. Blobel,et al.  Depletion of a single nucleoporin, Nup107, prevents the assembly of a subset of nucleoporins into the nuclear pore complex , 2003, Proceedings of the National Academy of Sciences of the United States of America.

[41]  Morris F. Maduro,et al.  Identification and cloning of unc-119, a gene expressed in the Caenorhabditis elegans nervous system. , 1995, Genetics.

[42]  Sebastian A. Leidel,et al.  Functional genomic analysis of cell division in C. elegans using RNAi of genes on chromosome III , 2000, Nature.

[43]  Yuji Kohara,et al.  Large-scale analysis of gene function in Caenorhabditis elegans by high-throughput RNAi , 2001, Current Biology.

[44]  P. Zipperlen,et al.  Functional genomic analysis of C. elegans chromosome I by systematic RNA interference , 2000, Nature.

[45]  T. Moore,et al.  Open-reading-frame sequence tags (OSTs) support the existence of at least 17,300 genes in C. elegans , 2001, Nature Genetics.

[46]  F. McKeon,et al.  Mutations in the nuclear lamin proteins resulting in their aberrant assembly in the cytoplasm. , 1988, The EMBO journal.

[47]  M. Paulin-Levasseur,et al.  MAN1, an Inner Nuclear Membrane Protein That Shares the LEM Domain with Lamina-associated Polypeptide 2 and Emerin* , 2000, The Journal of Biological Chemistry.

[48]  T. Giddings,et al.  Yeast nuclear pore complex assembly defects determined by nuclear envelope reconstruction. , 2000, Journal of structural biology.

[49]  U. Kutay,et al.  Transport between the cell nucleus and the cytoplasm. , 1999, Annual review of cell and developmental biology.

[50]  P. Hieter,et al.  Novel role for a Saccharomyces cerevisiae nucleoporin, Nup170p, in chromosome segregation. , 2001, Genetics.

[51]  R. Schekman,et al.  ER export: public transportation by the COPII coach. , 2001, Current opinion in cell biology.