Congenital Heart Disease Genetics Uncovers Context-Dependent Organization and Function of Nucleoporins at Cilia

Dev Cell. 2016 Sep 12;38(5):478-92. doi: 10.1016/j.devcel.2016.08.002. Epub 2016 Sep 1.

Abstract

Human genomics is identifying candidate genes for congenital heart disease (CHD), but discovering the underlying mechanisms remains challenging. In a patient with CHD and heterotaxy (Htx), a disorder of left-right patterning, we previously identified a duplication in Nup188. However, a mechanism to explain how a component of the nuclear pore complex (NPC) could cause Htx/CHD was undefined. Here, we show that knockdown of Nup188 or its binding partner Nup93 leads to a loss of cilia during embryonic development while leaving NPC function largely intact. Many data, including the localization of endogenous Nup188/93 at cilia bases, support their direct role at cilia. Super-resolution imaging of Nup188 shows two barrel-like structures with dimensions and organization incompatible with an NPC-like ring, arguing against a proposed "ciliary pore complex." We suggest that the nanoscale organization and function of nucleoporins are context dependent in a way that is required for the structure of the heart.

Keywords: 3D nanoscopy; Xenopus tropicalis; congenital heart disease; heterotaxy; left-right patterning; nuclear pore complex; nucleoporin; super-resolution.

Publication types

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

MeSH terms

  • Animals
  • Cilia / genetics
  • Cilia / pathology
  • Gene Knockdown Techniques
  • Genome, Human
  • Heart Defects, Congenital / genetics
  • Heart Defects, Congenital / metabolism*
  • Heart Defects, Congenital / pathology
  • Heterotaxy Syndrome / genetics*
  • Heterotaxy Syndrome / pathology
  • Humans
  • Nuclear Pore / genetics
  • Nuclear Pore / metabolism
  • Nuclear Pore Complex Proteins / chemistry
  • Nuclear Pore Complex Proteins / genetics
  • Nuclear Pore Complex Proteins / metabolism*
  • Protein Conformation
  • Protein Interaction Maps / genetics
  • Protein Transport / genetics
  • Xenopus / genetics
  • Xenopus Proteins / chemistry
  • Xenopus Proteins / genetics*
  • Xenopus Proteins / metabolism

Substances

  • Nuclear Pore Complex Proteins
  • Nup188 protein, Xenopus
  • Nup93 protein, human
  • Xenopus Proteins