What's a Picornavirus?
Polioviruses have 11 known proteins. Four of these proteins are used to construct the icosahedral capsid (VP1-4). Another one of these proteins, VPg, is involved in viral replication. Three of these proteins are nonstructural, and are used as proteases, and another is RNA-dependent-RNA polymerase. One picornaviruses enter a host cell, they begin making complementary RNA to their genome (mRNA) in the form of a long polyprotein. This polyprotein, once cleaved, makes up the different viral proteins listed above. Viral replication (See Replication) occurs when the virus uses the mRNA polyprotein as a template to produce a complementary strand of DNA. This strand is genomic material for new viruses. When the viruses are ready to leave the host cell, the cell is destroyed.
Some other random facts: picornaviruses contain no glycoproteins, it has myristic acid, is insensitive to ether, chloroform, and nonionic detergents, is stable at room temperature, and are sometimes unstable at more acidic environments unless stabilized by cations. Picornaviruses have narrow host ranges, and are transmitted horizontally (not passed on from parent to child).
Aside from that, major differences exist between each of the different
genera of picornavirus. Although there are five of them, including
Aphtoviruses, Cardiovirus, Enterovirus, Hepatovirus, and
Rhinovirus, this page will only deal with the three that cause
human disease: Enterovirus, Hepatovirus , and Rhinovirus.
Check 'em out!
Some important viral species affecting humans: polioviruses, coxsackieviruses, echoviruses, rhinoviruses, and hepatitis A virus.
Some important viral species affecting animals: swine vesicular disease virus, bovine enteroviruses, encephalomyocarditis viruses, foot-and-mouth disease viruses, simian hepatitis A virus.
This is an especially imporant virus family because of its ability to cause so many different types of disease in humans. Picornaviruses can affect the human heart, the central nervous system, cause strange bumps all over the body, give you a cold, and damage the liver. For more info on specific diseases caused by the picornavirus family, check these out:
The Common Cold
"I sneezed a sneeze into the air
it fell to earth I know not where
but you should have seen the looks on those
in whose vicinity I snoze"
For more quotable cold quotes, click here.