Compositionally distinct nuclear pore complexes of functionally distinct dimorphic nuclei in the ciliate Tetrahymena

J Cell Sci. 2017 May 15;130(10):1822-1834. doi: 10.1242/jcs.199398. Epub 2017 Apr 6.


The nuclear pore complex (NPC), a gateway for nucleocytoplasmic trafficking, is composed of ∼30 different proteins called nucleoporins. It remains unknown whether the NPCs within a species are homogeneous or vary depending on the cell type or physiological condition. Here, we present evidence for compositionally distinct NPCs that form within a single cell in a binucleated ciliate. In Tetrahymena thermophila, each cell contains both a transcriptionally active macronucleus (MAC) and a germline micronucleus (MIC). By combining in silico analysis, mass spectrometry analysis for immuno-isolated proteins and subcellular localization analysis of GFP-fused proteins, we identified numerous novel components of MAC and MIC NPCs. Core members of the Nup107-Nup160 scaffold complex were enriched in MIC NPCs. Strikingly, two paralogs of Nup214 and of Nup153 localized exclusively to either the MAC or MIC NPCs. Furthermore, the transmembrane components Pom121 and Pom82 localize exclusively to MAC and MIC NPCs, respectively. Our results argue that functional nuclear dimorphism in ciliates is likely to depend on the compositional and structural specificity of NPCs.

Keywords: FG-Nup; Nuclear dimorphism; Nuclear envelope; Nucleoporin; Y-complex.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Conserved Sequence
  • Macronucleus / metabolism
  • Micronucleus, Germline / metabolism
  • Models, Biological
  • Nuclear Pore / metabolism*
  • Nuclear Pore Complex Proteins / chemistry
  • Nuclear Pore Complex Proteins / metabolism*
  • Permeability
  • Protein Domains
  • Protein Structure, Secondary
  • Protozoan Proteins / chemistry
  • Protozoan Proteins / metabolism
  • Sequence Homology, Amino Acid
  • Tetrahymena thermophila / metabolism*


  • Nuclear Pore Complex Proteins
  • Protozoan Proteins