Histone Modification - Epigenetic Modification

Question 1

What is Histone Modification

Answer 1

Another type of modification

In a nucleas of a eukaryotic cell, DNA wraps around the octamer of histone proteins to form nucleosomes

Globular domains of the histone can directly affect transcription and nucleasome stability .

Question 2

Evidence

Answer 2

Recent work has shown that histone core modification can not only direct regulate transcription , but have an influence of DNA repair /replication

Question 3

What are histone methylation

Answer 3

Process by which methyl groups are transferred to amino acids of histone proteins

Make up nucleosomes

Question 4

Affect gene expression

Answer 4

Activities of histone methyltrasnferease are offset by the activity of hi stone demethylases enabling the switching on and off of transcription by reversing pre - existing modification .

Plays an important role in assembly of the hetrerhchormatin mechanisms passing down to progeny affected by the environment - Subject to epigenetic altercations .

Mutations - Increase and decrease methyalation have great change on gene regulation

Enzymes altered

If oncogenes become unmethylated increased the chances of mutation .

If genes are highly methylated , tumour suppressor genes was not active susceptible to mutation.