Question

In heterochromatin formation, which of the following are responsible for recruiting histone deacetylases and histone methyltransferases to a nucleation site?

1) DNA methyltransferases
2) Histone acetyltransferases
3) Transcription factors
4) Polycomb group proteins

Answer 1

Polycomb group proteins are responsible for recruiting histone deacetylases and histone methyltransferases during heterochromatin formation, which leads to gene silencing by preventing transcription machinery from accessing DNA.

Step-by-step explanation:

In the process of heterochromatin formation, the recruitment of histone deacetylases and histone methyltransferases to a nucleation site is predominantly the responsibility of Polycomb group proteins. These proteins play a critical role in modifying the chromatin structure, leading to the transcriptional repression of genes. They facilitate the 'silencing' of gene expression by creating a closed chromosomal configuration that prevents RNA polymerase and transcription factors from accessing the DNA. While DNA methyltransferases, histone acetyltransferases, and transcription factors do influence chromatin structure and gene expression, they have different roles in chromatin remodeling and gene regulation.