Mutations within the Open Reading Frame (ORF) including Ochre stop codon of the Surface Glycoprotein gene of SARS-CoV-2 virus erase potential seed location motifs of human non-coding microRNAs.

MicroRNA are short and non-coding RNA, 18-25 nucleotides in length. They are produced at the early stage of viral infection. The roles played by cellular miRNAs and miRNA-mediated gene-silencing in the COVID-19 epidemic period is critical in order to develop novel therapeutics. We analysed SARS-CoV-2 Surface Glycoprotein (S) nucleotide sequence originating from India as well as Iran, Australia, Germany, Italy, Russia, China, Japan and Turkey and identified mutation in potential seed location of several human miRNA. Seventy single nucleotide polymorphisms (SNP) were detected in the S gene out of which, 36, 32 and 2 were cases of transitions, transversions and deletions respectively. Eleven human miRNA targets were identified on the reference S gene sequence with a score >80 in the miRDB database. Mutation A845S erased a common binding site of 7 human miRNA (miR-195-5p, miR-16-5p, miR-15b-5p, miR-15a-5p, miR-497-5p, miR-424-5p and miR-6838-5p). A synonymous mutation altered the wild type Ochre stop codon within the S gene sequence (Italy) to Opal thereby changing the seed sequence of miR-511-3p. Similar (synonymous) mutations were detected at amino acid position 659 and 1116 of the S gene where amino acids serine and threonine were retained, abolishing potential seed location for miR-219a-1-3p and miR-20b-3p respectively. The significance of this finding in reference to the strategy to use synthetic miRNA combinations as a novel therapeutic tool is discussed.