title: Nup120p: a yeast nucleoporin required for NPC distribution and mRNA transport.
abstract: To extend our understanding of the mechanism by which the nuclear pore complex (NPC) mediates macromolecular transport across the nuclear envelope we have focused on defining the composition and molecular organization of the yeast NPC. Peptide sequence analysis of a polypeptide with a M(r) of approximately 100,000 present in a highly enriched yeast NPC fraction identified a novel yeast nucleoporin we term Nup120p. Nup120p corresponds to the open reading frame (ORF) YKL057c identified by the yeast genome sequencing project. The ORF predicts a protein with a calculated molecular mass of 120.5 kD containing two leucine zipper motifs, a short coiled-coil region and limited primary sequence similarity to Nup133p. Nup120p was localized to the NPC using a protein A-tagged chimera in situ by indirect immunofluorescence microscopy. Deletion of the NUP120 gene caused clustering of NPCs at one side of the nuclear envelope, moderate nucleolar fragmentation and slower cell growth. Transfer of nup120 delta cells to 37 degrees C resulted in the nuclear accumulation of poly(A)+ mRNA, extensive fragmentation of the nucleolus, spindle defects, and cell death.
authors.affiliation: Laboratory of Cell Biology, Howard Hughes Medical Institute, Rockefeller University, New York 10021-6399, USA.
authors.forename: J D
authors.initials: JD
authors.lastname: Aitchison
authors.forename: G
authors.initials: G
authors.lastname: Blobel
authors.forename: M P
authors.initials: MP
authors.lastname: Rout
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D001692:Biological Transport / Q000235:genetics; D015415:Biomarkers; D005455:Fluorescent Antibody Technique; D017353:Gene Deletion; D005800:Genes, Fungal / Q000502:physiology; D008854:Microscopy, Electron; D008969:Molecular Sequence Data; D009685:Nuclear Envelope / Q000737:chemistry* / Q000378:metabolism / Q000648:ultrastructure; D028861:Nuclear Pore Complex Proteins; D009687:Nuclear Proteins / Q000032:analysis / Q000235:genetics / Q000302:isolation & purification*; D012333:RNA, Messenger / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins; D012680:Sensitivity and Specificity; D013696:Temperature; D015003:Yeasts / Q000166:cytology / Q000235:genetics* / Q000648:ultrastructure
chemical_list: D015415:Biomarkers; C097740:NUP120 protein, S cerevisiae; D028861:Nuclear Pore Complex Proteins; D009687:Nuclear Proteins; D012333:RNA, Messenger; D029701:Saccharomyces cerevisiae Proteins