The question asks to identify post-translational modifications (PTMs) involved in the epigenetic control of gene expression.
Epigenetic Control Mechanisms
Epigenetic control refers to modifications that alter gene expression without changing the underlying DNA sequence. Key mechanisms include modifications to DNA itself and modifications to histone proteins, which package DNA.
Analyzing Options for PTMs in Epigenetics
- Arginine methylation: This is a PTM occurring on histone proteins. Methylation of arginine residues in histones can alter chromatin structure and is recognized as a mechanism involved in epigenetic gene regulation. Thus, it fits the criteria.
- Lysine acetylation: This is a major PTM on histone proteins. Acetylation neutralizes the positive charge of lysine, loosening chromatin structure and generally promoting gene transcription. It is a well-established epigenetic regulatory mechanism. Thus, it fits the criteria.
- Cytosine methylation: This modification occurs directly on the DNA base cytosine (forming 5-methylcytosine). While a crucial epigenetic mechanism, it is a modification of the DNA molecule itself, not a post-translational modification of proteins.
- Cytosine deamination: This is a chemical reaction that can alter DNA bases and is often involved in DNA repair pathways or spontaneous mutations. It is not typically classified as a primary mechanism for epigenetic *control* of gene expression.
Conclusion on Epigenetic PTMs
Based on the analysis, both Arginine methylation and Lysine acetylation are PTMs directly involved in the epigenetic regulation of gene expression through histone modification.
Therefore, the correct options are Arginine methylation and Lysine acetylation.
Important Questions from Regulation of Gene Expression
- Which of the following conditions induce(s) the expression of $ \beta$-galactosidase gene in the lac operon?
Determine the correctness or otherwise of the following Assertion [a] and the Reason [r].
Assertion [a]: In multicellular organisms, cells of different lineages have different gene expression profiles.
Reason [r]: Alternative splicing is the only mechanism to generate protein diversity.- The event(s) that lead(s) to inactivation of tumor suppressor genes in cancer cells is(are)
- Which of the following statement(s) is(are) CORRECT regarding the $lac$ operon in $E. coli$ when grown in the presence of glucose and lactose?
Determine the correctness or otherwise of the following Assertion [a] and the Reason [r]
Assertion: Ab initio gene finding algorithms that predict protein coding genes in eukaryotic genomes are not completely accurate.
Reason: Eukaryotic splice sites are difficult to predict.
