Self Replicating Proteins May be a Clue to Life Origins

The proteins in our body must not only be the right configuration, but the right shape. Prions are misfolded proteins that are also self replicating which can cause biological systems to malfunction such as forming holes in the brain called spongiform encephalitis (Mad Cow disease or Crutchfield Jacobs disease in humans).

Prions can spread from one organism to another by mouth, blood or contaminated surfaces. Like infectious viruses, prions can also have variants, or strains, that produce different effects, not all of which are harmful. Unlike the rest of biologically active structures, prions don’t have information-storage molecules like DNA or RNA, yet they are able to copy and transmit biological information. This has strained the idea that all replication of proteins must come from an information coding system like DNA or RNA. While it does put some strain on the validity of our conventional interpretations of how things happen in evolution and biology (that proteins are “only” manufactured from DNA to RNA and then to final form as protein), it may also be a clue to our origins. (Note* retroviruses are also known to violate this rule, called the central dogma of molecular biology)

Some researchers have proposed that it may be possible, due to the ease with which amino acids and peptides can be produced by abiotic means; that the first protocells may have been proteins only encapsulated in lipid membranes. (For more information look up Fox’s protein microspheres). These microspheres may have only acquired nucleic acids as an adaptation later on as a means information storage related to reproduction.

In other words; it is thought that proteins may have reproduced themselves by some autocatalytic process at first, like that which we see in prions today. Evidence for this can be seen in the fact that there are still noncoded peptides in certain bacteria to this day (See Day, 1979, p. 369). Is it possible that proteins began working in mutually beneficial symbiotic relation to each other and some of which eventually specialized in information storage and protein synthesis” This type of relationship dynamic is known to have happened in the case of mitochondria and chloroplasts, Eukaryotes are thought to originated as symbiotic prokaryote organisms that fused into obligate (necessary-inseparable) form.

Is it possible that RNA and DNA were adaptive strategies in service of prions? Is the behavior of prions a clue to our origins? Time may tell.

Here’s more on Prions:


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