Yeast is able to maintain a plastic heterochromatin structure

The genetic material in eukaryotes is packaged into chromatin. The chromatin structure is orchestrated such that euchromatic regions are relatively uncondensed and accessible to factors that bind DNA whereas heterochromatic regions are densely packaged into higher-order conformations. The compact nature for heterochromatin sets a natural barrier for protein recruitment and thereby potentially endangers normal DNA metabolism, such as DNA replication and recombination.

 

On Jan 13th, the PLoS Genetics journal published the latest findings of Dr. Jin-Qiu Zhou’s group from SIBCB, SIBS, CAS. They found that the histone acetyltransferase complex NuA4 was targeted to telomeric heterochromatin and specifically acetylated histone H4 on lysine 12. Targeted histone acetylation provided a way for cells to maintain a relatively plastic heterochromatin structure that is necessary for DNA metabolisms within telomeric heterochromatin. Therefore, although heterochromatic domains are largely silenced, they are not as static as we previously assumed and the dynamic aspect of heterochromatin is directly attributable to changes in its own chemical properties.

 

This work was supported by grants from the Ministry of Science and Technology of China and the National Natural Science Foundation of China.