N1-Methylpseudouridine (abbreviated m1Ψ) is a natural

archaea Archaea ( ) is a Domain (biology), domain of organisms. Traditionally, Archaea only included its Prokaryote, prokaryotic members, but this has since been found to be paraphyletic, as eukaryotes are known to have evolved from archaea. Even thou ...

tRNA Transfer ribonucleic acid (tRNA), formerly referred to as soluble ribonucleic acid (sRNA), is an adaptor molecule composed of RNA, typically 76 to 90 nucleotides in length (in eukaryotes). In a cell, it provides the physical link between the gene ...

component, and "hypermodified"

pyrimidine Pyrimidine (; ) is an aromatic, heterocyclic, organic compound similar to pyridine (). One of the three diazines (six-membered heterocyclics with two nitrogen atoms in the ring), it has nitrogen atoms at positions 1 and 3 in the ring. The oth ...

nucleoside Nucleosides are glycosylamines that can be thought of as nucleotides without a phosphate group. A nucleoside consists simply of a nucleobase (also termed a nitrogenous base) and a five-carbon sugar (ribose or 2'-deoxyribose) whereas a nucleotid ...

used in biochemistry and molecular biology for ''

in vitro ''In vitro'' (meaning ''in glass'', or ''in the glass'') Research, studies are performed with Cell (biology), cells or biological molecules outside their normal biological context. Colloquially called "test-tube experiments", these studies in ...

'' transcription and is found in the

SARS-CoV-2 Severe acute respiratory syndrome coronavirus 2 (SARS‑CoV‑2) is a strain of coronavirus that causes COVID-19, the respiratory illness responsible for the COVID-19 pandemic. The virus previously had the Novel coronavirus, provisional nam ...

mRNA In molecular biology, messenger ribonucleic acid (mRNA) is a single-stranded molecule of RNA that corresponds to the genetic sequence of a gene, and is read by a ribosome in the process of Protein biosynthesis, synthesizing a protein. mRNA is ...

vaccines tozinameran (

Pfizer Pfizer Inc. ( ) is an American Multinational corporation, multinational Pharmaceutical industry, pharmaceutical and biotechnology corporation headquartered at The Spiral (New York City), The Spiral in Manhattan, New York City. Founded in 184 ...

–

BioNTech BioNTech SE ( ; or short for Biopharmaceutical New Technologies) is a German multinational biotechnology company headquartered in Mainz that develops immunotherapies and vaccines, particularly for cancer and infectious diseases. The compan ...

) and elasomeran (

Moderna Moderna, Inc. ( ) is an American pharmaceutical and biotechnology company based in Cambridge, Massachusetts, that focuses on RNA therapeutics, primarily mRNA vaccines. These vaccines use a copy of a molecule called messenger RNA (mRNA) to carry inst ...

Properties

N1-Methylpseudouridine is the

methylated Methylation, in the chemical sciences, is the addition of a methyl group on a substrate, or the substitution of an atom (or group) by a methyl group. Methylation is a form of alkylation, with a methyl group replacing a hydrogen atom. These term ...

derivative of

pseudouridine Pseudouridine (5-ribosyluracil, abbreviated by the Greek letter psi- Ψ) is an isomer of the nucleoside uridine in which the uracil is attached via a carbon-carbon instead of a nitrogen-carbon glycosidic bond. Pseudouridine is the most abundant ...

. It is used in ''in vitro'' transcription and for the production of RNA vaccines. In vertebrates, it stimulates significantly less activation of the innate immune response compared to

uridine Uridine (symbol U or Urd) is a glycosylated pyrimidine analog containing uracil attached to a ribose ring (or more specifically, a ribofuranose) via a β-N1- glycosidic bond. The analog is one of the five standard nucleosides which make up nuc ...

, while the translation is stronger. In protein biosynthesis, it is read like uridine and enables comparatively high protein yields. The nucleoside itself can be made by chemical methylation of pseudouridine. While pseudouridine can wobble-pair with bases other than A, work examining COVID-19 modRNA vaccines that replace all their uridines with N1-methylpseudouridine show faithful protein production. More recent work from Mulroney and colleagues has identified that N1-methylpseudouridine can give rise to slippery sequences that promote ribosomal frameshifting. This issue is readily correctable through the replacement of slippery sequences with synonymous codons. The frameshifting is not known to contribute to any safety issues with regard to current mRNA vaccines, nor has it been shown to limit their effectiveness. In work from Mulroney and colleagues, mice immunized with the Bnt162b2 vaccine (Pfizer–BioNTech) demonstrate a greater T cell response against in-frame spike protein than those receiving Vaxzevria (Oxford–AstraZeneca), despite the latter not demonstrating meaningful production of frameshifted sequences. In human donors, the degree of recognition of frameshifted peptides by T cells varies greatly, suggesting that the extent to which frameshifting occurs may vary greatly as well. Importantly, frameshifted products are rare but well-defined events in protein production, including in viral infections, and can give rise to sequences that can be targeted by the immune system. Furthermore, despite significant disparity at the level of nucleotide sequences between COVID-19 vaccines from Pfizer/BioNTech and Moderna, the safety profile of both vaccines is comparable, arguing against any meaningful effect of frameshifting on the safety profile of the vaccines.

History

In 2016, a protocol for large-scale synthesis of the

nucleoside triphosphate A nucleoside triphosphate is a nucleoside containing a nitrogenous base bound to a 5-carbon sugar (either ribose or deoxyribose), with three phosphate groups bound to the sugar. They are the molecular precursors of both DNA and RNA, which are chai ...

from the

ribonucleoside A ribonucleoside is a type of nucleoside including ribose as a component. One example of a ribonucleoside is cytidine Cytidine (symbol C or Cyd) is a nucleoside molecule that is formed when cytosine is attached to a ribose ring (also known as a ...

was published. In 2017–2018 it was tested in vaccines against

Zika Zika fever, also known as Zika virus disease or simply Zika, is an infectious disease caused by the Zika virus. Most cases have no symptoms, but when present they are usually mild and can resemble dengue fever. Symptoms may include fever, conju ...

HIV-1 The subtypes of HIV include two main subtypes, known as HIV type 1 (HIV-1) and HIV type 2 (HIV-2). These subtypes have distinct genetic differences and are associated with different epidemiological patterns and clinical characteristics. HIV-1 e ...

influenza Influenza, commonly known as the flu, is an infectious disease caused by influenza viruses. Symptoms range from mild to severe and often include fever, runny nose, sore throat, muscle pain, headache, coughing, and fatigue. These sympto ...

, and

Ebola Ebola, also known as Ebola virus disease (EVD) and Ebola hemorrhagic fever (EHF), is a viral hemorrhagic fever in humans and other primates, caused by ebolaviruses. Symptoms typically start anywhere between two days and three weeks after in ...

References

{{DEFAULTSORT:Methylpseudouridine, N1- Nucleosides Pyrimidines Methyl compounds