Question

How do picornaviruses achieve cell entry and how does this process differ from that used by enveloped viruses? What checkpoints are involved in the process? What are the roles of the “canyon” and the pocket factor?

Answer 1

How do picornaviruses achieve cell entry and how does this process differ from that used by enveloped viruses? What checkpoints are involved in the process? What are the roles of the “canyon” and the pocket factor?

Pico Rna viruses are the viruses are the non enveloped viruses that have icosahedron capsids. The capsid is tightly packed. The genome itself is infectious. Rna When enters into the celm the infectivity would be increased. The genome of these bacteria are positive sense. The genome of Pickens virus also has a UTR region, with a polyprotein present at the 3’ end of the genome. The polyprotein has the following sequence “L-1ABCD-2ABC-3ABCD” .

There are multiple rna elements present in the genome of the picornavirus. In order to achieve replication, there is requirement of the cre element or the cis acting replication element. The viral particle would be binding to the surface of the cell. The cell surface would be having a serotype particular for the picornavirus. As a result of this binding, there would be conformational changes in the capsid protein of the virus, with the release of the myristic acid.

This acid would be making a pore on the membrane of the cell, and the rna gets injected through this pore. After, the rna enters the cell, it would be unconfined the positive strand of the rna and the genome will be replicated by the help of the rna dependent rna Polymerase enzyme. Translation would be taking place through the use of host ribosomes and throughthe IRES.

Canyon binding receptors as well as pocket factors would be competing with one another for binding to the cell. The canyon is in the form of circular depression present around the ecosahedral shapes, where, receptors would be binding. As the receptor molecules would be binding to the canyon, they would be removing the pocket factor which is a lipid molecule. As the receptor would be binding to the canyon, it would be depressing the floor of of the canyon and the roof of the pocket.