Role of the Ndc1 Interaction Network in Yeast Nuclear Pore Complex Assembly and Maintenance

J Cell Biol. 2009 May 4;185(3):475-91. doi: 10.1083/jcb.200810030.

Abstract

The nuclear pore complex (NPC) mediates all nucleocytoplasmic transport, yet its structure and biogenesis remain poorly understood. In this study, we have functionally characterized interaction partners of the yeast transmembrane nucleoporin Ndc1. Ndc1 forms a distinct complex with the transmembrane proteins Pom152 and Pom34 and two alternative complexes with the soluble nucleoporins Nup53 and Nup59, which in turn bind to Nup170 and Nup157. The transmembrane and soluble Ndc1-binding partners have redundant functions at the NPC, and disruption of both groups of interactions causes defects in Ndc1 targeting and in NPC structure accompanied by significant pore dilation. Using photoconvertible fluorescent protein fusions, we further show that the depletion of Pom34 in cells that lack NUP53 and NUP59 blocks new NPC assembly and leads to the reversible accumulation of newly made nucleoporins in cytoplasmic foci. Therefore, Ndc1 together with its interaction partners are collectively essential for the biosynthesis and structural integrity of yeast NPCs.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cell Survival
  • Cytoplasm / physiology*
  • Kinetics
  • Luminescent Proteins / genetics
  • Membrane Glycoproteins / metabolism
  • Methionine / metabolism
  • Nuclear Pore / physiology*
  • Nuclear Pore / ultrastructure
  • Nuclear Pore Complex Proteins / deficiency
  • Nuclear Pore Complex Proteins / genetics
  • Nuclear Pore Complex Proteins / metabolism
  • Nuclear Proteins / deficiency
  • Nuclear Proteins / genetics
  • Nuclear Proteins / metabolism
  • Nuclear Proteins / physiology*
  • Recombinant Fusion Proteins / metabolism
  • Saccharomyces cerevisiae / cytology
  • Saccharomyces cerevisiae / physiology*
  • Saccharomyces cerevisiae / ultrastructure
  • Saccharomyces cerevisiae Proteins / genetics
  • Saccharomyces cerevisiae Proteins / metabolism
  • Saccharomyces cerevisiae Proteins / physiology*

Substances

  • Luminescent Proteins
  • Membrane Glycoproteins
  • NDC1 protein, S cerevisiae
  • NUP53 protein, S cerevisiae
  • Nuclear Pore Complex Proteins
  • Nuclear Proteins
  • POM152 protein, S cerevisiae
  • Recombinant Fusion Proteins
  • Saccharomyces cerevisiae Proteins
  • Methionine