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lncRNA are very weird and I think they challenge some of the common, traditional assumptions about how cells work. Basically, the traditional view of RNA was th
by bglazer 2y ago
lncRNA are very weird and I think they challenge some of the common, traditional assumptions about how cells work. Basically, the traditional view of RNA was that it's a messenger between the DNA and proteins. That is, it just functions a way to transfer genomic information to the protein factories (ribosomes). There were some widely known exceptions to this, like ribosomal RNA, which forms essential parts of the structure of ribosomes, so it's not just a messenger, it actually has a functional role in building a key cellular machine. My sense was that was viewed as a weird edge case that ribosome biologists were concerned with.
Anyways, there's been an explosion of different classes of RNA in the past decade or so. This has been driven by new techniques in RNA sequencing technology that allow us to detect and sequence RNA in a more unbiased and high-throughput way. What we saw was a huge number and variety of RNA molecules in cells that don't look like they encode any protein. So, this fundamentally breaks that assumption about RNA's role as "just" a messenger.
The best characterized class of these weird new non-coding RNA's is probably micro-RNA. They're very short stretches of non-protein-coding RNA, and it seems that they bind to other sequences of RNA and prevent their translation to proteins. So, RNA has at least one layer of self-regulation. Then we see long non-coding RNA. They can act as "sponges" or buffers of microRNA by preferentially binding to miRNA, preventing the micro-RNA's interaction with their normal protein coding RNA targets. So, there's another layer: long non-coding RNA buffers microRNA which inhibits translation of messenger RNA. Further the long RNA can also condensate into these structures that are similar to droplets of oil in water. They're transitory structures that form and dissolve then reform quickly and repeatedly. What they do is still a bit vaguely understood but they seem to bring together very weakly interacting proteins and RNA in concentrations that wouldn't be possible just by diffusion within the cell. So, there's another layer of regulation: long coding RNAs form condensates to that allow interactions between proteins that wouldn't happen otherwise.
All of this is complicated by the fact that these things have other weird properties. They aren't expressed very frequently, so they're hard to detect. They're not very well conserved evolutionarily, i.e. their sequences diverge rapidly between species. They don't really have fixed structures, they're more just like floppy, sticky noodles. This would typically indicate they're not functional or at least non-essential. How could this be important? It's an RNA that doesn't make a protein, isn't very abundant, has no defined shape, and evolution doesn't seem to care much about the details of its sequence.
*But*, as this paper shows, they're absolutely essential for cellular function. If you take them out of cells, the cells die.
So, all that to say that the idea of biology as working like a little computer; just a series of linear information transmission steps, is probably rather misleading in many cases. Instead it's a tangled mess of weak interactions that depends on subtle biochemical effects like condensation. It's noisy and imprecise at the molecular level, but all the self-interacting layers of regulation and interaction somehow give rise to remarkably precise and adaptive responses at the tissue and organismal level.
- nickpsecurity 2y agoThanks for that detailed description. It’s also a great argument for the God hypothesis. We expect to find a lot of discoveries like this. The kind that make us think it could’ve never happened by chance. They keep turning up, too.
- bglazer 2y agoImagine a creator who could design a universe that evolves over 13 billion years and countless trillions of living creatures to generate you and me and the rest of humanity. To me, thats much more amazing than a designer who builds life like a really complicated lego kit. In fact it’s almost insulting to imply that God couldn’t create our world through evolution. Evolution is so much more beautiful and complex than the (easily comprehensible) image of a guy tinkering in a celestial garage.
- nickpsecurity 2y agoThere’s three types of knowledge at play here: revelatory, scientific, and speculative. Science can’t tell us who built the universe, why, or with what outcome. Only the Creator can if they choose to. God giving us His Word is revelation. He gave proof although He says He’ll supernaturally let anyone humbly seeking Him know it’s true upon hearing it. https://gethisword.com/evidence.html https://gethisword.com/evidence.html In His Word, God says He created us in an intimate way like a potter forms clay. A form He takes later when Jesus Christ lives among us to save us. He created us over six days. He also set in motion laws that allow things to further optimize within their environments. He allowed similar algorithms (eg GA’s) to be used to solve problems for us. God is really good to us. That’s just the start, though. Every worldview has a foundation. His involves objective morality, a design that benefits us, and love for each other. All things were to be done that way. He blessed nations that did. Those who did the opposite increased in strife, violence, and sickness. Most sinful nations perished while God’s nation, Israel, was re-created out of thin air as prophesied. Adaptations Darwin noticed were too tiny to cover the universe’s and life’s design and complexity. The normal rules of science don’t allow huge leaps from tiny mechanisms to massive systems. Yet, people from sinful backgrounds didn’t want God to be real because they’d face the consequences of their sins. They needed theories that let them be gods, in control. So, they traded both divine revelation and scientific observations for fanciful speculation with zero proof. Their atheist religion included fifty to a hundred precise laws that just spontaneously emerge, a universe with 100% reliability by accident, kinds turning to other kinds millions of times with virtually no transitional forms, life just spontaneously emerging (eg Cambrian period) after extinctions, and making excuses for why we never observe this in over a billion animals today. Those believing this took over academia, media, and film. They force the views on all in their sphere with opposite views usually censored, even with evidence. The new worldview, that we’re just chemical configurations in a meaningless universe with death a helpful tool of progress, gave rise to horrors. Racial superiority, eugenics, forced sterilization, and genocide are directly justifiable by evolution theory. By subjectivism, any evil under the sun can be justified since morality is perceived to be imaginary. Sure enough, the culture justified more evil over time. How they entertain themselves now, music or movies, is people being vicious, treating others like objects, using them for sex/money, theft, rape, murder, and recently glorifying the name of Satan. God’s Word predicted these specific things would increase which means they’re further evidence it’s true. Not only bad science, the atheist, liberal, evolutionary worldview takes us into moral depravity that thoroughly damages us. This should not be tolerated by scientists. Within science, it is opposite of the scientific method that says to discard theories consistently disproven by observed data. They must build on observations. Outside of science, it ignores all the evidence of God’s Word being a superior model with better results. We must build on the truth with love which is a worldview that God blesses and more people benefit from.