1. transcriptional
1.1. These mechanisms prevent/promote transcription
1.1.1. Acetylation
1.1.1.1. addition of acetyl groups to dna histons, promotes transcription
1.1.2. methylation
1.1.2.1. addition of methyl groups, prevents transcription
1.1.3. phosphorylation
1.1.3.1. addition of phosphate groups, promotes transcription
2. post-transcriptional
2.1. These mechanisms control or regulate mRNA after it has been produced
2.1.1. Alternative RNA Processing
2.1.1.1. regulatory proteins specific to cell type control intron-exon choices (different combinations of introns and exons to create new phenotypes)
2.1.2. mRNA Degradation
2.1.2.1. Poly-A tail shortening etc.
2.1.3. Initiation of Translation
2.1.3.1. regulatory proteins can bind to specific sequences within the UTR at the 5’ end of the mRNA so that ribosomes cannot attach and translation cannot occur (distals, proximals)
2.1.4. Protein Processing and Degradation
2.1.4.1. Proteasome, where protein goes to be degraded into protein fragments (peptides).
3. translational
3.1. These mechanisms prevent translation. They often involve protein factors needed for translation
3.2. miRNA's and siRNA's
3.2.1. can black translation and degrade DNA
3.2.2. microRNA is a double stranded hairpin structure produced by trimming a large precursor molecule
3.2.3. siRNA is formed from longer double-stranded RNA that produces many siRNA's
4. post-translational
4.1. These mechanisms act after the protein has been produced
4.1.1. ubiquitin can bind to a protein and signal it for destruction,