Hdm Test 2: Viral Structure/entry

Front 1

What are viruses made of?

Back 1

Protein, nucleic acids, lipids, sugars

Front 2

3 types of virus coatings

Back 2

complex, enveloped (with lipid coat), naked viruses

Front 3

General size of virus

Back 3

50-100 nm

Front 4

Pathogenic viruses in respiratory tract

Back 4

rhinovirus, influenze A/B/C, RSV, PIV, Measles Mumps, Coronaviruses (SARS), Adenoviruses, Epstein-Barr, cytomegalovirus, HSV

Front 5

Impact of structure on Respiratory tract viruses

Back 5

Doesn;t necessarily matter

Front 6

Viral genome functions

Back 6

Genome replication, assembly and packaging, regulation of replication, modulation of host defences (no protein synthesis machinery, energy, membrane biosynthesis)

Front 7

Purpose of secondary structure in HIV gene

Back 7

Regulation of gene expression

Front 8

4 classic viruses to consider structure

Back 8

Rabies (raptovirus), HSV1, HIV, AdV

Front 9

How does the rabies virus protect its genome?

Back 9

Protein encrusted to prevent degradation, lends itself to helical shape

Front 10

Surrounding structure of AdV

Back 10

Protein

Front 11

HSV surrounding layers

Back 11

Lipid envelope and protein capsid

Front 12

HIV surrounding layers

Back 12

Protein capsid, secondary capsid, lipid membrane

Front 13

Shape of lipid enveloped viruses

Back 13

pleomorphic (many) (depends on from which cell it came)

Front 14

What is the same for virus architecture?

Back 14

Structure and assembly

Front 15

Basic unit of viral structure

Back 15

Capsid protein

Front 16

Function of capsid protein?

Back 16

Protect vNA, interact specifically with vNA for packaging, Interact w/ host receptors, Allow for release of vNA, Assist viral/host gene regulation

Front 17

Ways to study viral structure

Back 17

electron microscopy, cryo-EM, x-ray diffraction

Front 18

Best resolution for viral study

Back 18

X-ray crystallography

Front 19

two protein coat types

Back 19

icosahedral (spherical, 20 sided, limited NA)
helical (rod shaped, no limit to NA)

Front 20

Principles of virus architecture

Back 20

Viral genome insufficient to code for more than a few diff proteins, identical subunits, packed to provide each with identical environment

Front 21

Where are enveloped viruses derived from?

Back 21

Host cell membranes (composition varies)

Front 22

What else do virus envelopes contain in addiiton to membranes?

Back 22

Virally encoded proteins=glycoproteins (for structure)
Sometimes host cell proteins

Front 23

What do the envelope glycoproteins form?

Back 23

Spikes on surface of virion

Front 24

Ex of viruses that have glycoproteins

Back 24

Semliki Forest virus, Dengue virus

Front 25

Goal of virus attachment

Back 25

Bring close to cell surface (3D->2D)

Front 26

How does IFV and PIV attach?

Back 26

Use Hemaggluttinin glycoprotein to attach to sialic acid (lots in respiratory tract)
-Good affinity resulting in strong avidity bc of numbers

Front 27

How does RSV attach?

Back 27

Has glycoprotein that doesn't bind, but is highly glycosylated. These bring "fusogenic protein" of virus closer to PM, looks like normal cell surface on airway.

Front 28

How do viruses enter into cells? (2)

Back 28

-Membrane fusion, genome dump
-Receptor mediated endocytosis

Front 29

How do Viruses address endosome changes in clathrin-coated pits?

Back 29

Don't activate until pH drops. Must delay so not to rupture before replication

Front 30

How do influenze viruses enter cells?

Back 30

Receptor-mediated endocytosis (requires pH change)

Front 31

How do parainfluenza viruses enter cells?

Back 31

Surface fusion

Front 32

How do adenoviruses enter the cell?

Back 32

Receptor mediated endocytosis with fiber R and integrin

Front 33

2 options of viral load destination

Back 33

cytoplasm or nucleus