SARS coronavirus 2: from genome to infectome

Abstract

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) belongs to the group of Betacoronaviruses. The SARS-CoV-2 is closely related to SARS-CoV-1 and probably originated either from bats or pangolins. SARS-CoV-2 is an etiological agent of COVID-19, causing mild to severe respiratory disease which escalates to acute respiratory distress syndrome (ARDS) or multi-organ failure. The virus was first reported from the animal market in Hunan, Hubei province of China in the month of December, 2019, and was rapidly transmitted from animal to human and human-to-human. The human-to-human transmission can occur directly or via droplets generated during coughing and sneezing. Globally, around 53.9 million cases of COVID-19 have been registered with 1.31 million confirmed deaths. The people > 60 years, persons suffering from comorbid conditions and immunocompromised individuals are more susceptible to COVID-19 infection. The virus primarily targets the upper and the lower respiratory tract and quickly disseminates to other organs. SARS-CoV-2 dysregulates immune signaling pathways which generate cytokine storm and leads to the acute respiratory distress syndrome and other multisystemic disorders.

Multilevel systems biology analysis of lung transcriptomics data identifies key miRNAs and potential miRNA target genes for SARS-CoV-2 infection

“…SARS-CoV-2 virus has a single stranded RNA genome, whose size ranges from 29.8 kb to 29.9 kb [ 3 ] [ 4 ]. The genomic repertoire of SARS-CoV-2 is as follows; 5’-UTR, replication complex genes (ORF1a and ORF1b) encoding 16 non-structural proteins, structural protein encoding genes like spike (S), envelope (E), membrane (M), and nucleocapsid (N), few accessory protein encoding ORFs (ORF3a, ORF6, ORF7a, ORF7b, ORF8 and ORF9), 3’-UTRs and a Poly Adenine Tail [ 5 ]. Structural proteins facilitate the viral entry to host cells, its assembly and maturation, whereas non-structural proteins are mostly involved in genetic replication and transcription.…”

Bioinformatics Prediction of SARS-CoV-2 Epitopes as Vaccine Candidates for the Colombian Population

“…SARS-CoV-2 belongs to the beta genus of the Coronaviridae family, a group of single stranded positive sense RNA viruses able to affect humans and animals [10]. The name of Vaccines 2021, 9, 797 2 of 21 this type of viruses comes from the Latin word "corona" that means crown, given due to the appearance of the lipid envelope of the virions, which presents distinctive club-shaped projections [11].…”

Interplay between SARS‐CoV‐2‐derived miRNAs, immune system, vitamin D pathway and respiratory system

“…Canonical biogenesis of miRNA is a multi‐step process involving transcription of viral miRNA gene by RNA pol II and formation of a structure called as pri‐miRNA, its breakdown by Drosha endonuclease and DiGeorge syndrome critical region 8 (DGCR8) complex in the form of a hairpin structure called as pre‐miRNA, its extraction from the nucleus and maturation through Dicer endonuclease, eventually joining the RNA‐induced silencing complex (RISC) and suppressing expression of host genes 15 . Cell penetration by SARS‐CoV‐2 is mediated by membrane fusion process, in which a +ssRNA‐sense genome is delivered into the cytoplasm, serving as a template for virus replication process utilizing virally encoded RNA‐dependent RNA polymerase (RdRp), and ultimately, protein synthesis in fact, miRNA biogenesis process in cytoplasmic viruses is performed by non‐canonical miRNA biogenesis pathways in Drosha‐ or Dicer‐independent manner 16,17 . It has recently been shown that one of the main mechanisms of virus pathogenesis is targeting key human genes and suppressing their expression through viral miRNAs 18 .…”