Lysine Acetylation Gets A Big Boost

When proteins in a cell are accessorized with methyl, phosphate, or acetyl groups, these so-called posttranslational modifications switch on or off major cellular functions, such as cell division or gene expression. An in-depth look at proteins that get acetylated at their lysine residues now reveals that this form of posttranslational modification regulates a much more diverse portfolio of cellular functions than previously thought, says Chunaram Choudhary, who conducted the study with Matthias Mann of the Max Planck Institute for Biochemistry, in Martinsreid, Germany, and coworkers (Science, DOI: 10.1126/science.1175371). Lysine acetylation was already known to control aspects of gene expression, but the new study fingers the modification as also playing a part in DNA repair, how cells control their three-dimensional appearance, and the trafficking of vesicles in and out of cells. The team used antibodies that recognize lysine acetylation to extract these acetylated proteins from human cells coupled with mass spectrometry to identify 3,600 lysine acetylation sites on 1,750 proteins—six times more sites than were previously known. The team subsequently found that deacetylase inhibitor treatment, which is an anticancer strategy, increases lysine acetylation of histone proteins in cells.