COVID-19 pandemic in first seven months has led to more than 15 million confirmed infected cases and 600,000 deaths. SARS-CoV-2, the causative agent for COVID-19 has proved a great challenge for its ability to spread in asymptomatic stages and a diverse disease spectrum it has generated. This has created a challenge of unimaginable magnitude not only affecting human health and life but also potentially generating a long-lasting socioeconomic impact. Both medical sciences and biomedical research have also been challenged consequently leading to a large number of clinical trials and vaccine initiatives. While known proteins of pathobiological importance are targets for these therapeutic approaches, it is imperative to explore other factors of viral significance. Accessory proteins are one such trait that have diverse roles in coronavirus pathobiology. Here we analyze certain genomic characteristics of SARS-CoV-2 accessory protein ORF8, predict upon its protein features and review current available literature regarding its function. We have also undertaken review of ORF8 homolog ORF8ab from SARS-CoV with a purpose of developing holistic understanding of these proteins for reason that coronaviruses have been infecting humans repeatedly and might continue to do so. Despite low nucleotide and protein identity and differentiating genome level characteristics, there appears to be significant structural integrity and functional proximity between these proteins pointing towards their high significance. There is further need for comprehensive genomics and structural-functional studies to lead towards definitive conclusions regarding their criticality and that can eventually define their relevance to therapeutics development.

Placenta-derived stem cells (PDSCs) offer the advantages of possessing mesenchymal and embryonic traits, broad differentiation potential, large-scale availability, and no ethical constraints in their utilization in therapeutic applications. Elevated protein synthesis and consequently enhanced protein maintenance networks become necessary both due to the requirement to maintain stemness and respond to different stresses. This study aimed to identify the primary determinants of proteotoxic stress response in PDSCs. We generated heat-induced dose-responsive proteotoxic stress models of three stem cell types DBMSCs, DPMSCs, and pMSCs, and measured stress induction through biochemical and cell proliferation assays. RT-PCR array analysis of 84 genes involved in protein folding and protein quality control led to the identification of Hsp70 isoforms HSPA1A and HSPA1B as the prominent ones among 17 significantly expressed genes and with further analysis at the protein level through western blotting. A 24-hours’ time series analysis of stress-response allowed a detailed kinetic analysis of HSPA1A and HSPA1B gene and protein expression. More prominent differences between the two Hsp70 isoforms were detected at the translational level eluding to a potential higher requirement for HSPA1B during proteotoxic stress in PDSCs. To conclude, consideration should be given to the manipulation of definitely characterized chaperones at their expression or functional levels when utilizing PDSCs in therapeutic and regenerative applications.