Extremophiles and Horizontal Gene Transfer: Clues to the Emergence of Life

Jheeta, Sohan

doi:10.1002/9781119593096.ch16

Cited by 1 publication

(2 citation statements)

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“…Despite the fact that Archaea and Bacteria exhibit all of the defining characteristics of cells including the encoding of genomic information into DNA, mature ribosomes, and sophisticated biomembranes [ 53 , 54 ], they are distinctly different from one another so as to be classed as two distinct domains [ 50 , 55 , 56 ]. Nevertheless, species from both of these domains have been found to exhibit coding regions for PrPs.…”

Section: Antiquity Inventories Of Prion Proteins and Amyloidsmentioning

confidence: 99%

“…Even given a plentiful supply of monomers and a vigorous abiotic synthesis of RNA oligomers, there remains the question as to how such oligomers might have been amplified; remembering that the rate of oligomerization needs to exceed the rate of destruction. The required rapid amplification of RNA oligomers may need the presence of an RNA replicase enzyme for template-directed complementary RNA replication, in order to increase the much needed rapid amplification rate [ 55 ]. If, indeed, RNA amplification depends on protein catalysis and cannot proceed without it, then it must be concluded that prebiotic protein must have arisen marginally prior to rise of RNA—i.e., a protein-first hypothesis, though in this case, we are promulgating prions and prion-like molecules first hypothesis [ 71 ].…”

Section: Rna Amplification and Protectionmentioning

confidence: 99%

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The Way forward for the Origin of Life: Prions and Prion-Like Molecules First Hypothesis

Jheeta¹,

Chatzitheodoridis

Devine

et al. 2021

Life

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In this paper the hypothesis that prions and prion-like molecules could have initiated the chemical evolutionary process which led to the eventual emergence of life is reappraised. The prions first hypothesis is a specific application of the protein-first hypothesis which asserts that protein-based chemical evolution preceded the evolution of genetic encoding processes. This genetics-first hypothesis asserts that an “RNA-world era” came before protein-based chemical evolution and rests on a singular premise that molecules such as RNA, acetyl-CoA, and NAD are relics of a long line of chemical evolutionary processes preceding the Last Universal Common Ancestor (LUCA). Nevertheless, we assert that prions and prion-like molecules may also be relics of chemical evolutionary processes preceding LUCA. To support this assertion is the observation that prions and prion-like molecules are involved in a plethora of activities in contemporary biology in both complex (eukaryotes) and primitive life forms. Furthermore, a literature survey reveals that small RNA virus genomes harbor information about prions (and amyloids). If, as has been presumed by proponents of the genetics-first hypotheses, small viruses were present during an RNA world era and were involved in some of the earliest evolutionary processes, this places prions and prion-like molecules potentially at the heart of the chemical evolutionary process whose eventual outcome was life. We deliberate on the case for prions and prion-like molecules as the frontier molecules at the dawn of evolution of living systems.

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