Coronavirus have been making people sick for eons. They are among the many viruses which causes common cold. Although most of its members causes mild symptoms, few of them can lead to serious illnesses & even deaths.
The coronavirus got its name from its shape that seemed like a reminiscent of a monarch’s crow but were actually it’s spikey proteins. The name signifies less of its genetic material and more of how it appears under the microscopy.
The genetic material of Coronavirus comprises of a (+) ss-RNA, which is a chemical cousin of DNA. Genetically all the coronavirus are quite different from one another, some being as different as a human and a Giraffe. The most dangerous members of this family are the SARA, MERS and SARS-CoV-2. The SARS & MERS have caused some deadly outbreaks in the pasts.
The novel virus SARS CoV-2 was discovered in or aroundWuhan, China in the late Dec of 2019 and since then it has taken up around 3.72 lacs lives (as of 31st May,2020). Its name reflects its genetic similarity to the original SARS coronavirus, but with around 6000 mutations sprinkled all over the genetic material. Think of it as whole milk versus skim milk.
SARS-CoV-2 has customized itself with a different set of genes called accessories which give this new virus a little advantage in specific situation.
A take on the Anatomy of this new enemy
The virus is actually a virion consisting of four different proteins, an outer membrane and a single stranded RNA which forms the genome. The outer membrane, made of lipids, breaks up when it encounters soaps and water, which is why hand-washing is such a valuable barrier to infection.
The spike glycoprotein(S) which gives the virus its crown like appearance is present on the membrane and is considered the most prominent protein as it helps in establishing the infection. The membrane also holds other proteins called the envelope protein(E) and the membrane protein(M)which provides structural integrity. The fourth protein is the nucleocapsid(N) which acts as a scaffold around which the virus wraps the RNA.
How the virus hijacks the body
Upon coming in contact with the cells, the spike proteins of the virus act as a key and unlocks the door into our body by attaching to the ACE-2 proteins, present on the lung cells (Typically Type II-pneumocytes of alveoli). On its entrance, it uses a second weapon called the TMPRSS2, a protease, to have a better effect. This protease cuts open the spike protein, exposing a stump called a fusion peptide which lets the virion into the cell.
Once inside the cell, the virion releases its own soldiers and backup team to capture their land of pneumonocyte cells. The first ones to be released is the RNA, whose goal is to get replicated and code for polyproteins. The RNA in itself is like a cluster/group of soldiers (the genes) with each having their own role to play. These members of RNA align themselves like a single strand with one end responsible for coding for the four structural proteins and eight genes for small accessory proteins that inhibits the host’s defences. This forms just a third of the total forces. The rest of the group members form a different troop called ORFs which is responsible for creating two big polyproteins that cut themselves into 16 non-structural proteins (NSPs). These NSPs make up the machinery for copying and proofreading the genome.
After a while, the cell gets completely hijacked with the production of structural proteins and the RNA, that are assembled by the host cell itself to create many more enemies. And once the cell has created many, it releases armies of such virions out of the cell host cell membrane.
These newly formed virions now start attacking the other territories of the lung & the body and in thisway, they cause severe infections like pneumonia followed by death.
The globalization has indeed become a boon for the SARS-CoV-2 but it will surely be the reason for its downfall as the scientists all over the globe are working rigorously towards finding a stop to this. Until a vaccine is created, everyone is requested to stay safe, stay healthy and prevent the spread by maintaining a physical distancing.