Examples of methylation in the following topics:
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- Proteins can be chemically modified with the addition of methyl, phosphate, acetyl, and ubiquitin groups.
- Methyl groups are added to proteins via the process of methylation; this is the most common form of post-translational modification.
- Methylation on side chain nitrogens is considered largely irreversible while methylation of the carboxyl groups is potentially reversible.
- Methylation in the proteins negates the negative charge on it and increases the hydrophobicity of the protein.
- Methylation on carboxylate side chains covers up a negative charge and adds hydrophobicity.
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- Mechanisms of epigenetic silencing of tumor suppressor genes and activation of oncogenes include: alteration in CpG island methylation patterns, histone modifications, and dysregulation of DNA binding proteins.
- In cancer cells, the DNA in the promoter region of silenced genes is methylated on cytosine DNA residues in CpG islands, genomic regions that contain a high frequency of CpG sites, where a cytosine nucleotide occurs next to a guanine nucleotide .
- This combination of DNA methylation and histone deacetylation (epigenetic modifications that lead to gene silencing) is commonly found in cancer.
- Because these changes are temporary and can be reversed (for example, by preventing the action of the histone deacetylase protein that removes acetyl groups, or by DNA methyl transferase enzymes that add methyl groups to cytosines in DNA) it is possible to design new drugs and new therapies to take advantage of the reversible nature of these processes.
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- They are chemical modifications (phosphate, methyl, or acetyl groups) that are attached to specific amino acids in the protein or to the nucleotides of the DNA.
- When this configuration exists, the cytosine member of the pair can be methylated (a methyl group is added).
- Highly-methylated (hypermethylated) DNA regions with deacetylated histones are tightly coiled and transcriptionally inactive.
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- In E. coli, after replication, the nitrogenous base adenine acquires a methyl group; the parental DNA strand will have methyl groups, whereas the newly-synthesized strand lacks them.
- Thus, DNA polymerase is able to remove the incorrectly-incorporated bases from the newly-synthesized, non-methylated strand.
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- One known mechanism involves a type of postsynaptic glutamate receptor: NMDA (N-Methyl-D-aspartate) receptors .
- Next, Ca2+ ions entering the cell initiate a signaling cascade that causes a different type of glutamate receptor, AMPA (α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid) receptors, to be inserted into the postsynaptic membrane.
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- In the simple molecule butene (C4H8), the two methyl groups (CH3) can be on either side of the double covalent bond central to the molecule.
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- Some of the important functional groups in biological molecules include: hydroxyl, methyl, carbonyl, carboxyl, amino, phosphate, and sulfhydryl groups.
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- Methyl mercury is usually present in very low concentrations in natural environments, but it is highly toxic because it accumulates in living tissues.
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- Some of the bases of pre-rRNAs are methylated for added stability.