Histone H1 is one of the five main histone protein families which are components of chromatin in eukaryotic cells. Though highly conserved, it is nevertheless the most variable histone in sequence across species.
Scientists have discovered why histone 1 is a major protection factor against genomic instability and a vital protein for the organism.
The study explains for the first time that the suppression of histone 1 causes cell damage and genomic instability (DNA damage).
The deregulation of a commonly suppressed region of chromatin, called heterochromatin, leads to defects in information transcription, which in turn gives rise to the accumulation of DNA and RNA hybrids, the so-called R-loops, which are lethal.
Heterochromatin contains genetic information that is not translated for proteins but that comprises repetitive sequences that the cell silences and that is tightly regulated.
Both R-loops and the information held in heterochromatin have natural functions but when they are deregulated they are lethal.