Question

What receptor does Rubella use to attach to the host?

What general mechanism does Rubella use for entry?

Answer 1

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First lets know what Rubella virus is ?

The Rubella Virus is the virus that causes viral infection called rubella.It is also called German measles.Rubella virus is a positive strand RNA virus of the family Togaviridae.

Structure of Rubella Virus :

The Rubella virus is an enveloped virus,which means it has an envelop on the outside.It is oval or circular in shape and 60nm in diameter.Viruses with envelop are quite as virulent as non enveloped viruses.The rubella virus consists of the typical viral components with the genetic material ( single stranded RNA) being in the middle of the body covered by capsid and then the envelope.It differs from other viruses by lacking tegument (viral matrix) between the capsid and envelope.The genetic scope is similar to human DNA which tells the virus what to do, how to look like etc.This information is important as it tells the virus when to replicate and produce more viruses.

Outside the genetic material is the capsid.The capsid only protects the RNA of the virus and is shaped like a 20 sided polygon.The capsid has a capsid protein that is responsible for a number of functions.Its main function is to help the virus and RNA to replicate properly.

Finally the capsid is surrounded by the envelope . The envelope serves two functions - first is to protect the entire virus and second function is to attach to a host cell.The envelope is a lipid bilayer containing specialized glycoproteins (E1 and E2) which is said to be responsible for attachment to the host cell.It is also believed that a pH of 6.0 or less induces changes in the glycoproteins making attachment of the viral envelope to host cells.

The mechanism through which Rubella Virus enters the host cell is called ENDOCYTOSIS.Once it is attached to a host cell, conformational changes occur in the capsid releasing the genetic information (viral RNA) into the host cell.Replication is slow with a latency period of 8-12 hrs.The structural proteins appearing in 12-16 hrs.

ENDOYTOSIS DEFINITION : is a cellular process in which substances/matters are taken in by a living cell by invagination of its membrane to form a vacuole.

In the reference image below you can see how the rubella virus attaches the host cell via glycoproteins present on the envelope and is releasing its genome into the host cell by simple endocytosis.

Hope the answer was helpful.

Thank you :)