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英文解说
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小木虫(金币+0.5):给个红包，谢谢回帖交流
有部分没有听清，错误在所难免，欢迎大家指正
So this is HIV. It’s a typical retrovirus meaning that it has an outer envelope and in the center it has two copies of RNA as well as an enzyme here in blue that reverse transcriptase which will automatically turn that RNA into DNA. The virus itself with the outer envelope protein actually directly infects T helper cells. The way it does this is that as it comes up to the cell surface. It uses receptors that are on T helper cells and excusive the T helper cells which are CD4 molecular which really defines T help cells that’s a surface receptor that binds the envelope protein. That causes conformation change that allow the second receptor to grapple the envelope this is the chemokine coreceptor also called CCR5 when we talk about that more. What happens now is the stock the envelope protein pierces through the from the virus into the host cell and starts to draw the two cell membrane, the cell membrane and the virus membrane together. And what autonomy happens is this fusion of those two membranes and the virus genetic material is injected accentually into the cell and the envelope protein is left the cell surface. The virus has a matrix of a caps protein shown here in green and red that accentually digested when it is into the cell. That releases the viral enzymes and the viral RNA. Here we have a reverse transcriptase which takes the viral RNA and use a host’s nucleotides converse that viral RNA into a single strand of DNA. While it does that it makes some random areas which are just characteristic of reverse transcriptase. It has very poor proof reading activity. That single strand DNA now is again reversetranscripted into a double strain DNA. At that point another enzyme that is coming with the virus in the beginning called integrase, accentually grapple the whole double strand DNA and carries it through the nuclear pore into the nucleus of the cell. Within the nucleus of the cell, it finds the host chromosome and basically the integrase enzyme makes a nick in the host DNA and allow for HIV to insert itself into the host chromosome. And that right there it’s what it establishes lifelong infection. Now RNA polymerase comes along and makes messenger RNA. Those messenger RNAs encode for different proteins they end up associated with the ribosomes at the surface of the rough endoplasmic reticulum. And here is a piece of mRNA that is making a envelope protein which is directly produce it into the endoplasmic reticulum and it shutter them through the endoplasmic reticulum and take into the cell surface where at the cell surface it becomes embedded in the cell membrane and at this point coalescing with other envelope protein that events produce. You have this cluster of proteins now on the surface of this infected cell. At the same time, there are other messenger RNAs has been produced that allow for translation of other viral proteins. So here are additional viral proteins being made which are going to be used to make of key components that the virus automatically is going to need. These are transported against the cell surface to the area where the envelope proteins are. And a strand of RNA as well as some of the enzymes are part of that complex. This then buds off the cell surface at this point but is still not mature virion because the polyprotein chain needs to still be digested into its component parts. That’s done by an enzyme called protease. Protease breakes up those polyprotein chains and automatically allows for them to coalesce and form the mature structures that make up a final virion that can go on now to infect other cells. Once that happens now the cells can produce tons of viruses and this is really what then keeps the whole process going. |
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