Question: Academic question.
I am just wanting to make sure I understand epigenetics. It means changes to a gene that switch it on or off so the gene is replicated and translated or not and this involves methylation and histone modification. Then there is also methylation at the nucleotide level so that the gene is replicated and translated so a protein is made from it but it will have a different shape to what it would have had without the changes. I was also thinking specifically of the insulin receptor. My understanding is that when there is hyperglycemia conditions the cells modify some of their receptors to stop too much glucose from entering the cells. And these changes must be at the nucleotide level so that the receptors are made but not be able to allow insulin to lock on to them. Is my understanding right about the epigenetics?

Yes your answer is helpful but I want to ask you a bit more.

From what I have read it is not only that new receptors are limited but that there are receptors that don't work. I assume that the protein is different. How do these come about. Is there something else at some stage after the mRNA has delivered the gene from the nucleus that takes place?

Thanks for your information.
What I understand now is that there is an epigenetic way where the gene is turned on or off so that the protein is made or not made.

Then there is a method that has nothing to do with epigenetics and that involves splicing out an intron. This changes the polypeptide that is made and hence when it is folded it is a different shape and that means it won't function in the same way.

So for the GLUT4 that I am interested in, the cell will will either make or not the receptor if the gene is turned on or off and that has to do with epigenetics. So the cell has the option of limiting the number of insulin receptors on its surface.

Then separate to that method is the isoform, where the intron is spliced out of the mRNA sequence in the nucleus and then when it is transcribed a different polypeptide is made so that when it is folded it has a changed function. So the same number of receptors might be made but some of them won't work. Rather like the locks being changed on the doors so insulin can't dock.

And when the conditions are favourable to the cells it will make the isoforms /polypeptides that work as a receptor when folded and the protein made.
Am I correct now?
Thanks again for your help in this subject. You have given me more knowledge in genetics.

Thanks again for your information.
I can see what you mean about my last sentence. I was thinking about insulin receptors when I wrote it. That if there is hypoglycemic conditions in the blood the muscle cells for instance will make some good receptors and some that don't work or a lower number of receptors to stop too much glucose from entering. If the blood glucose is back to normal levels then the cell will make insulin receptors that work and the number that it needs to get the right amount of glucose into the cell.

I am retired now but I am an analytical chemist and have been involved in various research when I worked at the UNSW. I have been interested in health issues for the last 20 years and have done my own private research but not by conventional means. I am using Vipassana or insight meditation to look at what is going on at the cellular level in my body. And I have been very successful at reversing disease. I had ovarian cancer stage 4 with metastasis to uterus, bowel and both lungs and type 2 diabetes in 1993 and had a spontaneous remission after doctors gave me 6 months to a year to live. And the diabetes gone too. Since then I have had another 7 incidents of cancer. The first of those I had another spontaneous remission but after that I used Vipassana and discovered that cancer was only stem-cell mediated immunity erroneously ignited in the body. The changes the cells make are deliberate and they are fully reversible. cancer involves foul play by toxic people some of which are related to me, i.e., toxic relatives among them. So I was able to deliberately effect cancer remission and now can stage-manage my biology so I don't get cancer anymore.
I am involved in bring this information to the public. No doubt I have upset many toxic people AND people in big pharma.