HMGA biochemical modifications a labile regulatory code

HMGA biochemical modifications a labile regulatory code 

Over the last several years a substantial body of evidence has accumulated indicating the types and patterns of secondary biochemical modifications present on histones [42,43], transcriptional co-activators [44] and the HMGA proteins [33] 

Recent advances in mass spectrometry (MS) technology have provided researchers with an unparalleled ability to identify the types and patterns of secondary biochemical modifications found on proteins in living cells. Matrix-assisted laser desorption/ionization-MS (MALDI-MS) analyses have shown, for example, that HMGA proteins in vivo are simultaneously subject to complex patterns of phosphorylation, acetylation and methylation and that, within the same cell type, different isoforms of these proteins can exhibit quite different modification patterns [33]. Furthermore, these in vivo modifications have been demonstrated to markedly alter the binding affinity of HMGA proteins for both DNA and chromatin substrates in vitro [33]. Nevertheless, due to their number and complexity, it has been difficult to determine the actual biological function(s) played by these biochemical modifications in living cells. 

The use of MALDI-MS analysis alone to study in vivo protein modifications has several limitations, especially when it comes to identifying the specific amino acid 

Strategy for Identification of Sites of In vivo Post-Translational Modifications of HMGAl Proteins by Mass Spectrometry 

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