Human deaminase is on the new crown virus! Italian scholars have found evidence that the new coronavirus is being edited by RNA in the human body.

Novel coronavirus (SARS) novel coronavirus pneumonia (COVID-19) outbreak is a threat to global health. Recently, the outbreak of COVID-19 caused by this new virus has proved this risk.currently, the novel coronavirus pneumonia has caused more than 8 million 800 thousand infections worldwide and over 460 thousand deaths. In Brazil, the number of new cases increased to 54771 yesterday, with a new record on a single day, and the number of new infections in the United States has soared again.in addition, the number of new local cases in Beijing for several consecutive days reminds us that it is far from time to relax in the face of new coronavirus.recently, researchers from Siena University in Italy published a research paper entitled evidence for host dependent RNA editing in the transcript of sars-cov-2 in the latest issue of science advanced.researchers analyzed RNA novel coronavirus (SARS-CoV-2) in bronchoalveolar lavage fluid from 2 Wuhan patients. It was found that human host deaminase (APOBECs/ADARs) is involved in RNA editing of SARS-CoV-2 transcripts, which may have profound effects on the interaction between SARS-CoV-2 and patients.virus is a specific intracellular parasite. After a long co evolution process, the host has evolved a natural immune system to sense and suppress virus invasion, including endogenous deaminase mediated DNA and RNA editing.there are two kinds of deaminases in mammals: 1. ADARs targets double stranded RNA, which deaminases adenine (a) to hypoxanthine (I); 2. Apobecs targets single stranded RNA and converts cytosine (c) to uracil (U).apobecs / ADARs can interfere with virus replication, including coronavirus, but whether its enzyme activity is involved is unclear.in order to evaluate whether RNA editing occurs in host response to sars-cov-2 infection, the researchers obtained the RNA sequence data set of sars-cov-2 isolated from BALF of patients with covid-19 in Wuhan from the open database. The sequencing quality varies with samples, and only two samples have coverage and error rate suitable for identifying potential editing sites.487 single nucleotide variants (snvs) were identified using reditools 2, of which 41 were from patients with srr10903401446 from patients with srr10903402.the snvs of sars-cov-2 transcriptome were identified. The allele ratio of snvs was 1-5%, and there was a switching bias. The number of snvs was consistent with the mutation rate of coronavirus (10-6 / - 7).the change of a → g / T → C in sars-cov-2 transcriptome was observed, which may be caused by ADARs mediated a → I; while the C → T / g → a transition may be caused by apobecs mediated C → U.it is worth noting that the accumulation of snvs on most viral genes is directly proportional to gene length and sequencing depth. The only exception is the ORF6 gene, which regulates interferon signaling, which has a higher editing rate than other genes.sequence characteristics of sars-cov-2 RNA editing sites: since apobecs deaminase preferentially targets cytosine in a specific sequence environment, the researchers analyzed the trinucleotide environment of snvs. After genome normalization, there was no significant deviation in a → I change. The change of C → u mainly occurred at the 3 'position of thymine and adenine, which was consistent with Apobec1 deamination compatible mode ([Au] C [Au]).in addition, the most frequently edited trinucleotide is TCG, which is compatible with apobec3a mode (Ucn).nucleotide changes of different coronavirus strains in the family coronaviridae, researchers compared the genomes of existing coronaviruses, such as sars-cov-2, mers CoV and SARS CoV, to verify whether RNA editing might be responsible for some of the mutations obtained through evolution.genome alignment showed that a considerable number of mutations in all virus strains might come from C → u and a → I caused by deamination, and an editing compatible mode mediated by APOBEC also existed in snvs of genome C → U.the functional significance of RNA editing in sars-cov-2 remains to be explored: editing the genome of an invading virus may lead to virus death and may also promote virus evolution.as far as RNA viruses are concerned, the possibility of their death is greater than that of their evolution, because this will directly affect their genetic information.overall, novel coronavirus (SARS-CoV-2) transcripts were RNA edited by APOBECs/ADARs. Novel coronavirus (SARS-CoV-2) transmission is a common process in. This process may determine the fate of the virus and patients. 1. APOBEC3A inactivation is very common in Chinese population. This may play an important role in the transmission of new coronavirus (SARS-CoV-2). 2, because of the no correlation between editing and mutation, the two will help to select clinically effective therapeutic targets.paper links: