33 - hep C i

Question 1

what is hepatitis C, when was it discovered. what % of US is infected with it, and what is the major route of transmission

Answer 1

• Chronic liver infections
  
  • Cirrhosis
  • Liver cancer
• discovered around 1990, used to be called Hep non A non B
• Infects approx. 2 % of U.S. population
• Major route of transmission is illegal intravenous drugs (> 60%)
  
  • About 15 % of cases are sexually transmitted

Question 2

describe the structure of the hepatitus C virus. how is the protein cut into smaller pieces

Answer 2

• Single stranded RNA
  
  • 9600 bases long (very short piece of RNA)
  • One peptide is expressed – 3011 amino acids long
  • contains all of the proteins linked together
• Protein is cut into smaller proteins
  
  • First few are released by host proteases
  • Remaining are cut out by viral protease
• Virus has an RNA dependant RNA polymerase
  
  • Copies the viral RNA
• Virus proteins spontaneously assemble around viral RNA

Question 3

what was the 2020 nobel prize in medicine for

Answer 3

hepatitis C discovery

Question 4

what are the three ways that hep C is closely associated with lipids

Answer 4

• the proteins that this virus produces tend to have lipids formed as part of their outside structure. the entire structure of the virus involves a lot of lipoplysaccharaides
• Transported in blood to liver as a complex with lipopolysaccharaides
• Virus is replicated inside membrane of the endoplasmic reticulum
  
  • non-polar nature of the virus is very important to its replication
  • non polar environment of the ER is what allows the virus to copy itself

Question 5

what is the job of RNA dependant RNA polymerase and protease

Answer 5

• RNA dependant RNA polymerase
  
  • Makes copies viral RNA
  • successful drugs target this enzyme
• Protease
  
  • Cuts viral polypeptide into small proteins