In vitro assay and characterization of the farnesylation-dependent prelamin A endoprotease

J Biol Chem. 1997 Feb 21;272(8):5298-304. doi: 10.1074/jbc.272.8.5298.


The 72-kDa nuclear lamina protein lamin A is synthesized as a 74-kDa farnesylated precursor. Conversion of this precursor to mature lamin A appears to be mediated by a specific endoprotease. Prior studies of overexpressed wild-type and mutant lamin A proteins in cultured cells have indicated that the precursor possesses the typical carboxyl-terminal S-farnesylated, cysteine methyl ester and that farnesylation is required for endoproteolysis to occur. In this report, we describe the synthesis of an S-farnesyl, cysteinyl methyl ester peptide corresponding to the carboxyl-terminal 18 amino acid residues of human prelamin A. This peptide acts as a substrate for the prelamin A endoprotease in vitro, with cleavage of the synthetic peptide at the expected site between Tyr657 and Leu658. Endoproteolytic cleavage requires the S-prenylated cysteine methyl ester and, in agreement with transfection studies, is more active with the farnesylated than geranylgeranylated cysteinyl substrate. N-Acetyl farnesyl methyl cysteine is shown to be a noncompetitive inhibitor of the enzyme. Taken together, these observations suggest that there is a specific farnesyl binding site on the enzyme which is not at the active site.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Binding Sites
  • Cysteine / analogs & derivatives*
  • Cysteine / metabolism
  • Endopeptidases / analysis
  • Endopeptidases / metabolism*
  • HeLa Cells
  • Humans
  • Lamin Type A
  • Molecular Sequence Data
  • Nuclear Proteins / metabolism*
  • Protein Precursors / metabolism*


  • Lamin Type A
  • Nuclear Proteins
  • Protein Precursors
  • prelamin A
  • S-farnesylcysteine
  • Endopeptidases
  • prelamin A endoprotease
  • Cysteine