If lipids can directly modulate the activity of RNA in a simple synthetic system I wonder if the type of lipid is important. Like Omega 3 vs Omega 6...
Different fats do different things and there's nothing inherently special about omega 3 or 6, they just have double bonds in specific places. Sometimes certain fats are used as precursors for other compounds or making the cell membrane more or less fluid or modifying proteins but the way people talk about these fats its like they're mythologizing them. Its a little ridiculous.
Those two double bonds, while they seems insignificant, it causes the body to make two whole separate classes of endocannabinoids, PGE, COX and other inflammatory and anti-inflammatory mediators.
Plus, the lipids that surround the cell can change cell function dramatically.
Yes I'm aware how fats change the function of cells, that's exactly what I said in my previous comment. The only thing actually special about omega3/6 is that they are essential fatty acids meaning that we can't biosynthesize them.
But the thing is that all fatty acids can do these things, that was my point. Yes we need omega3/6 as precursor for some other compounds but that doesn't somehow make them special in such a way that they have anything to do with the subject at hand that we are posting on.
The article describes a few interesting things, among which is a scenario in which guanine is added to RNA to improve its adhesion to the lipid layer. One such example they noted was a G-quadruplex.
> Its not even a full clue, it's a 'possible clue'.
Sure. I said it elsewhere in another thread, but I think the bridge from physics to chemistry, while quite fantastic, is a lot easier to swallow than the bridge from chemistry to biology. I think everyone mostly agrees that this is a harder chasm to cross because of the sheer complexity of the cell.
At the root of it, the article suggests that the nature of the lipid layer could help catalyze the sort of reactions needed to (apparently?) insert RNA in a cell, or at least to get it to stick to the cell. But it's not clear at all that there's any real smoke here. G-quadruplex is an interesting, apparently naturally-occurring, molecule; are there others?
One other question that confuses me a little about this, too—and again, all I have are ignorant questions: wouldn't we see some heritage of these changes in cells? We have two broad classes of them (prokaryotes and eukaryotes), but are there antecedents that would give a sense of the evolutionary history of the cell? If the lipid layer is involved in somehow attracting and/or inserting RNA into a protocell, what kind of evidence would we see in cells today? Is it reasonable to suppose that we'd have some kind of biomarkers in the cell proper to show its changing complexity?
I suppose the answer to this is no--we shouldn't necessarily expect it. But at the same time, it seems like protocells as I've imagined are infrastructure more than they are a scaffold. Maybe that assumption is wrong; but if it is, the picture is muddier than ever: if the scaffold disappears without a trace, it leaves you in the awkward position of always hypothesizing without ever getting to how the building was made in the first place.
The G-quadruplex is not a molecule, it is a specific assembly of either molecules or structures within a single molecule
Something you need to understand for these long chain molecules is that they can fold in, around, and on themselves being held together by numerous weak molecular interactions. Proteins and DNA/RNA behave this way
TIL--thanks a bunch! I've been glad to see some related threads come up on HN lately on this issue, and it's been a fruitful source of (hopefully) intelligent distraction.
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[ 3.6 ms ] story [ 42.3 ms ] threadPlus, the lipids that surround the cell can change cell function dramatically.
https://en.m.wikipedia.org/wiki/Essential_fatty_acid
But the thing is that all fatty acids can do these things, that was my point. Yes we need omega3/6 as precursor for some other compounds but that doesn't somehow make them special in such a way that they have anything to do with the subject at hand that we are posting on.
Do we see/have other examples?
The weasel word usage of OoL media hype train is so cringe inducing once you notice it.
Sure. I said it elsewhere in another thread, but I think the bridge from physics to chemistry, while quite fantastic, is a lot easier to swallow than the bridge from chemistry to biology. I think everyone mostly agrees that this is a harder chasm to cross because of the sheer complexity of the cell.
At the root of it, the article suggests that the nature of the lipid layer could help catalyze the sort of reactions needed to (apparently?) insert RNA in a cell, or at least to get it to stick to the cell. But it's not clear at all that there's any real smoke here. G-quadruplex is an interesting, apparently naturally-occurring, molecule; are there others?
One other question that confuses me a little about this, too—and again, all I have are ignorant questions: wouldn't we see some heritage of these changes in cells? We have two broad classes of them (prokaryotes and eukaryotes), but are there antecedents that would give a sense of the evolutionary history of the cell? If the lipid layer is involved in somehow attracting and/or inserting RNA into a protocell, what kind of evidence would we see in cells today? Is it reasonable to suppose that we'd have some kind of biomarkers in the cell proper to show its changing complexity?
I suppose the answer to this is no--we shouldn't necessarily expect it. But at the same time, it seems like protocells as I've imagined are infrastructure more than they are a scaffold. Maybe that assumption is wrong; but if it is, the picture is muddier than ever: if the scaffold disappears without a trace, it leaves you in the awkward position of always hypothesizing without ever getting to how the building was made in the first place.
Something you need to understand for these long chain molecules is that they can fold in, around, and on themselves being held together by numerous weak molecular interactions. Proteins and DNA/RNA behave this way
https://en.m.wikipedia.org/wiki/G-quadruplex