COVID-19 Flashcards
Recall the features of Human SARS-Coronavirus.
Recall transmission, incubation, symptoms, and contagious period of SARS.
Recall the overview of the Human SARS-Coronavirus lifecycle.
Infection begins when the viral spike (S) glycoprotein attaches to its complementary host cell receptor. After attachment, a protease of the host cell cleaves and activates the receptor-attached spike protein. Depending on the host cell protease available, cleavage and activation allows the virus to enter the host cell by endocytosis or direct fusion of the viral envelope with the host membrane. On entry into the host cell, the virus particle is uncoated, and its genome enters the cell cytoplasm.
A number of the nonstructural proteins coalesce to form a multi-protein replicase-transcriptase complex (RTC). The main replicase-transcriptase protein is the RNA-dependent RNA polymerase (RdRp). It is directly involved in the replication and transcription of RNA from an RNA strand. The other nonstructural proteins in the complex assist in the replication and transcription process.
The replicated positive-sense genomic RNA becomes the genome of the progeny viruses. Progeny viruses are then released from the host cell by exocytosis through secretory vesicles.
Recall the difference in the gene sequence between SARS-CoV-1 and SARS-CoV-2
Recall the ssRNA genomic sequence of coronavirus.
What is the SARS-CoV receptor in humans?
ACE2 receptor
Recall the position of SARS-CoV-2 Spike protein in the gene sequence.
Cleavage site separates the RBD (Receptor Binding Domain) and the Fusion Protei
Recall the mechanism of spike protein activation in SARS-COV-1
Recall the location of ACE2 receptor expression.
ORF of the coronavirus gene are mostly responsible for ________________ and ________________.
RNA replication and host remodelling
Recall sites in the body that express both ACE2 as well as TMPRSS2.
Recall how SARS-CoV-2 Spike binding to ACE2 receptor drives respiratory pathogenesis.
By binding to ACE2, it also brings the receptor into the cell through endocytosis. The reduction of ACE2 levels in the membrane reduces its ability to inhibit Angiotensin II function. This then drives acute lung injury, adverse myocardial remodelling, vasoconstriction, and increase in vascular permeability.
Recall the production, regulation, and function of Angiotensin 2.
Recall the immune response against COVID-19.
Recall the effect of IFN-1 signalling to pathogenesis of COVID-19.