A Progeria Mutation Reveals Functions for Lamin A in Nuclear Assembly, Architecture, and Chromosome Organization

Proc Natl Acad Sci U S A. 2009 Dec 8;106(49):20788-93. doi: 10.1073/pnas.0911895106. Epub 2009 Nov 19.

Abstract

Numerous mutations in the human A-type lamin gene (LMNA) cause the premature aging disease, progeria. Some of these are located in the alpha-helical central rod domain required for the polymerization of the nuclear lamins into higher order structures. Patient cells with a mutation in this domain, 433G>A (E145K) show severely lobulated nuclei, a separation of the A- and B-type lamins, alterations in pericentric heterochromatin, abnormally clustered centromeres, and mislocalized telomeres. The induction of lobulations and the clustering of centromeres originate during postmitotic nuclear assembly in daughter cells and this early G1 configuration of chromosomes is retained throughout interphase. In vitro analyses of E145K-lamin A show severe defects in the assembly of protofilaments into higher order lamin structures. The results show that this central rod domain mutation affects nuclear architecture in a fashion distinctly different from the changes found in the most common form of progeria caused by the expression of LADelta50/progerin. The study also emphasizes the importance of lamins in nuclear assembly and chromatin organization.

Publication types

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

MeSH terms

  • Amino Acid Substitution / genetics
  • Cell Nucleus / metabolism*
  • Cell Nucleus / ultrastructure
  • Centromere / metabolism
  • Chromosome Positioning
  • Chromosomes, Human / metabolism*
  • Chromosomes, Human / ultrastructure
  • Crystallization
  • DNA Replication
  • HeLa Cells
  • Heterochromatin / metabolism
  • Heterochromatin / ultrastructure
  • Humans
  • Lamin Type A / genetics*
  • Lamin Type A / ultrastructure
  • Male
  • Mitosis
  • Mutant Proteins / metabolism
  • Mutation / genetics*
  • Progeria / genetics*
  • Telomere / metabolism

Substances

  • Heterochromatin
  • LMNA protein, human
  • Lamin Type A
  • Mutant Proteins