Transcription and its Regulation in Neurons

Central Dogma

Transcription is the start of the central dogma, which is genetic information flowing in one direction from DNA to RNA and lastly to a protein that the body can use wherever it needs it. There is an electric signal sent from your brain that chooses a strand of DNA with a specific gene and pulls it out of a chromosome. It is stretched until the appropriate gene is found in the order in the figure below.

Copying of DNA into RNA

Then a blank piece of pre-mRNA comes down and applies the opposite codons of the one on the DNA strand; the bindings are Adenine to Thymine and Cytosine to Guanine except the RNA switches Uracil instead of Thymine to bond to Adenine. They bond 5’ to 3’. This happens in the nucleus. Then leaves through nuclear pores and then gets picked up by a ribosome. This is used because the DNA is very stable and very important for the body to have so the body makes unstable copies of it in RNA to be able to transfer and get rid of if not needed anymore This gets processed until there is a terminator codon which tells the body to stop copying the information and the final product called RNA polymerase.

Splicing

Then after the copy of the DNA in pre-mRNA form is made it goes to a spliceosome which is an organelle in the eukaryotic cell which then cuts our pre-mRNA into introns and exons. The difference between the introns and exons is that exons are the expressive parts that are needed to make the protein and the introns are useless for this process so they are cut out from the exons to be disposed of. They use a cut called a layeriat to splice the exons together to keep them in a single strand. This then can be called mRNA after it has “matured”.

Epigenetics

Not a loss of a genome and often less and less stable. Adding an acetate (-CH3COOH) to histones turns genes on by opening up. Adding a methyl (-CH3) to histones turns genes off to condensing chromatin. This can change because of the experience and current expressed genes combination of those factors together that is what creates your epigenetics. The mix of things you can see and things you can’t about somebody.

Why does this apply to Neurons

Different neurotransmitters can have an effect on how certain genes or how transcription is being done by the nucleus. All cells in your body have DNA in them that is able to be copied and modified which applies all of these things to neurons as well. Neurons also send signals down for certain strands of DNA to be copied. Neurons like lots of other cells in the body are stuck in a non multiplying phase where they can’t create more so they have to be very careful with the DNA and how they handle it.

Reverse Transcriptase

Viruses enter the cell and get engulfed into the extracellular fluid. Those little RNA molecules are then taken into the nucleus and used in the reverse transcription to make viral DNA that the body will then use as the code to reproduce the virus all over the body.