DNA is never so sequestered as to escape the scrutiny of curious scientists. The latest peek inside the DNA bunker has been taken by scientists of the Institute of Molecular Biology in Mainz. “The chromatin compaction is reversible, and upon restitution of normoxia and nutrients, chromatin transiently adopts a more open structure than in untreated cells.”
The scientists found that the compacted state of chromatin reduces transcription, whereas the open chromatin structure induced upon recovery provokes a transitory increase in transcription.
Confirming these results, the scientists determined that condensed chromatin exhibits an increased resistance to digestion with DNAseI compared with chromatin in untreated cells and, additionally, that the mobility of linker histone H1, as estimated by fluorescent recovery after photobleaching, is significantly reduced by oxygen and nutrient deprivation.
According to the IMB scientists, the extent and reversibility of chromatin compaction induced by oxygen and nutrient deprivation suggests that the impact of ischemia could be constrained by targeting biochemical events that are required for chromatin condensation.
Alternative approaches may open up now that additional details of DNA compaction are becoming available.