Regulation of p53 function by lysine methylation.

The reversible and dynamic methylation of proteins on lysine residues can greatly increase the signaling potential of the modified factor. In addition to histones, several other nuclear factors such as the tumor suppressor and transcription factor p53 undergo lysine methylation, suggesting that this modification may be a common mechanism for modulating protein–protein interactions and key cellular signaling pathways. This article focuses on how lysine methylation events on the C-terminal tail of p53 are generated, sensed and transduced to modulate p53 functions.

The MBT repeats of L3MBTL1 link SET8-mediated p53 methylation at lysine 382 to target gene repression.

The p53 tumor suppressor protein is regulated by multiple post-translational modifications, including lysine methylation. We previously found that monomethylation of p53 at lysine 382 (p53K382me1) by the protein lysine methyltransferase (PKMT) SET8/PR-Set7 represses p53 transactivation of target genes. However, the molecular mechanism linking p53K382 monomethylation to repression is not known.

Methylation of the retinoblastoma tumor suppressor by SMYD2.

The retinoblastoma tumor suppressor (RB) is a central cell cycle regulator and tumor suppressor. RB cellular functions are known to be regulated by a diversity of post-translational modifications such as phosphorylation and acetylation, raising the possibility that RB may also be methylated in cells. Here we demonstrate that RB can be methylated by SMYD2 at lysine 860, a highly conserved and novel site of modification.

Modulation of p53 function by SET8-mediated methylation at lysine 382.

Reversible covalent methylation of lysine residues on histone proteins constitutes a principal molecular mechanism that links chromatin states to diverse biological outcomes. Recently, lysine methylation has been observed on nonhistone proteins, suggesting broad cellular roles for the enzymes generating and removing methyl moieties. Here we report that the lysine methyltransferase enzyme SET8/PR-Set7 regulates the tumor suppressor protein p53.