Module 3 Epigenetic Gene regulation

Question 1

• the addition of a methyl group (M) to the DNA base, cytosine.
• catalyzed by DNA methyltransferase (DNMT) enzymes
• occurs in the 5’ position of the C ring, producing 5-methylcytosine
• linked to transcriptional silencing
• important for gene regulation, development and tumorigenesis

Answer 1

DNA Methylation

Question 2

• Involve lysine residues
• when the tails of histone molecules are acetylated at specific
  locations, these molecules have less interaction with DNA, thereby
  leaving it more open.

Answer 2

Covalent Histone Modifications

Question 3

Small noncoding RNAs can also be involved in the regulatory processes
that form “silent” chromatin. MicroRNAs cause translational repression
(either at the level of initiation or elongation) or mRNA degradation (by
deadenylation)

Answer 3

Aberrant expression of microRNAs (miRNA)