Blocking farnesylation of the prelamin A variant in Hutchinson-Gilford progeria syndrome alters the distribution of A-type lamins

Nucleus. 2012 Sep-Oct;3(5):452-62. doi: 10.4161/nucl.21675. Epub 2012 Aug 16.

Abstract

Mutations in the lamin A/C gene that cause Hutchinson-Gilford progeria syndrome lead to expression of a truncated, permanently farnesylated prelamin A variant called progerin. Blocking farnesylation leads to an improvement in the abnormal nuclear morphology observed in cells expressing progerin, which is associated with a re-localization of the variant protein from the nuclear envelope to the nuclear interior. We now show that a progerin construct that cannot be farnesylated is localized primarily in intranuclear foci and that its diffusional mobility is significantly greater than that of farnesylated progerin localized predominantly at the nuclear envelope. Expression of non-farnesylated progerin in transfected cells leads to a redistribution of lamin A and lamin C away from the nuclear envelope into intranuclear foci but does not significantly affect the localization of endogenous lamin B1 at nuclear envelope. There is a similar redistribution of lamin A and lamin C into intranuclear foci in transfected cells expressing progerin in which protein farnesylation is blocked by treatment with a protein farnesyltransferase inhibitor. Blocking farnesylation of progerin can lead to a redistribution of normal A-type lamins away from the inner nuclear envelope. This may have implications for using drugs that block protein prenylation to treat children with Hutchinson-Gilford progeria syndrome. These findings also provide additional evidence that A-type and B-type lamins can form separate microdomains within the nucleus.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Alkyl and Aryl Transferases / antagonists & inhibitors
  • Alkyl and Aryl Transferases / metabolism
  • Animals
  • Cell Line
  • Cell Nucleus / metabolism
  • Enzyme Inhibitors / pharmacology
  • Lamin Type A / genetics
  • Lamin Type A / metabolism*
  • Mice
  • Mutation
  • Nuclear Envelope / metabolism
  • Nuclear Proteins / genetics
  • Nuclear Proteins / metabolism*
  • Progeria / metabolism
  • Progeria / pathology
  • Protein Precursors / genetics
  • Protein Precursors / metabolism*
  • Protein Prenylation / drug effects
  • Transfection

Substances

  • Enzyme Inhibitors
  • Lamin Type A
  • Nuclear Proteins
  • Protein Precursors
  • lamin C
  • prelamin A
  • Alkyl and Aryl Transferases
  • p21(ras) farnesyl-protein transferase