Researchers developed a new method to find proteins that unpack DNA, according to a study published on July 12, 2018.
This study was conducted by the researchers at Penn State. This new method helps in making the dense DNA more accessible for gene expression and other functions. The accessibility to DNA is essential for a variety of proteins for copying the information of DNA into RNA and make proteins. However, DNA is tightly wrapped around proteins called histones that are then packed into bead-like structures called nucleosomes, which makes it difficult for the proteins to bind to the DNA.
This problem is solved when the cells use nucleosome-displacing factors to invade the condensed DNA and open it up. Until now, a general method to screen for these factors and evaluate them was lacking. Nucleosome-displacing factors are a special kind of transcription factor, proteins that bind to short, specific sequences of DNA called binding sites to control gene expression. A fast, inexpensive method was developed by the researchers to screen and categorize large numbers of transcription factors based on their ability to displace nucleosomes. Using this method, the transcription factor binding sites are artificially incorporated into the nucleosomes and are examined to identify the factors that are capable of reducing the presence of nucleosomes.
Both new and previously known nucleosome-displacing factors were observed by the researchers. Factors such as ones that strongly deplete nucleosomes are found to be highly abundant in nucleus and bind very tightly to DNA. Few transcription factors that are capable of displacing nucleosomes without tapping into the DNA replication process were identified by the researchers. Furthermore, the researchers plan to extend this method to more complex systems such as mammals, and to different cell types and developmental stages.