Chapter 24

Question 1

the basic structure of herpes simplex virus

Answer 1

enveloped icosahedral with 6 different proteins and T=16 capsid, linear ds-DNA; envelope has 10 different glycoproteins; tegument between capsid and envelope with 14 glycoproteins

Question 2

HSV genes have

Answer 2

two Unique regions: U[L] and U[S], flanked by inverted repats

Question 3

“a” region is

Answer 3

packing signal and recombinations

Question 4

there are about

Answer 4

84 different genes (U[L]=65 and U[S]=14)

Question 5

recombination during replication creates

Answer 5

4 genome isomers, all being infectious

Question 6

“b” region and “c” region has

Answer 6

4 and 1 genes, respectively

Question 7

during infection, the HSV genome is adopted in

Answer 7

circular form

Question 8

human herpesvirus [alpha]

Answer 8

HSV 1&2 - Labial and genital lesions

Varcella-zoster virus - Shingles and Chickenpox

Question 9

human herpesvirus [gamma]

Answer 9

Epstein-Barr virus - mononucleosis

Human Herpesvirus 8 - Kaposi’s sarcoma

Question 10

human herpesviruses are latent virus

Answer 10

symptomless after initial infection, and maybe reactivated

Question 11

in HSV entry, initial attachment proteins are

Answer 11

gB & gC with initial receptor “heparan sulfate”

Question 12

in HSV entry, the second attachment protein is

Answer 12

gD with second receptor, “nectin-1 & HVEM”

Question 13

FUsion with PM occurs through

Answer 13

gB, gH and gL

Question 14

during the HSV entry, tegument is released in

Answer 14

cytoplasm after envelope fusion with PM

Question 15

capsid travels through the cytoplasm using

Answer 15

microtubule and dynein, with tegument proteins attached to the capsid

Question 16

when the capsid is attached to nuclear envelope,

Answer 16

DNA and associated proteins are released in the nucleus. the genome is circularized. VP16 tegument protein is also released.

Question 17

HSV transcription is done by

Answer 17

cDdRp II

Question 18

most mRNAs are

Answer 18

unspliced

Question 19

genes expressed in 3 temporal classes are:

Answer 19

immediate early (early gene activation), early (DNA replication, late gene activation), Late (structural proteins, regulatory proteins)

Question 20

[Alpha] proteins are

Answer 20

ICP0, ICP4, ICP22, ICP27, ICP47

Question 21

ICP0’s function is

Answer 21

promiscuous activator of gene transcription (viral and cellular). Acts as ubiquitin ligase (E3). Localizes to nuclear domain 10 structures

Question 22

ICP4’s function is

Answer 22

major regulatory protein, required for all [Beta] and [Gamma] virus gene expression. Binds to viral DNA; interacts with cellular transcription factors. Regulates transcription both positvely and negatively

Question 23

ICP22’s function is

Answer 23

enhancing the expression

Question 24

ICP27’s function is

Answer 24

blcoking DNA splicing

Question 25

ICP47's function is

Answer 25

blocking immune system

Question 26

[Alpha] genes are activated by

Answer 26

VP16 with host Oct-1 and HCF-1 on [Alpha]-gene transcription enhancer

Question 27

[Alpha]-gene transcription enhancer

Answer 27

TAATGARATT

Question 28

U[L]41 is for

Answer 28

degrading cellular mRNA and [alpha]-gene mRNA

Question 29

[Beta] proteins are

Answer 29

U[L]9, U[L]29 *ICP8, U[L]5+U[L]8+U[L]52, U[L]30, U[L]42

Question 30

U[L]9's function is

Answer 30

binding to replication origin, Ori S,S, L and meting dsDNA

Question 31

ICP8's function is

Answer 31

binding to ss-DNA

Question 32

U[L]5,8,52 is

Answer 32

helicase-primase complex

Question 33

U[L]30 is

Answer 33

DNA polymerase

Question 34

U[L]42 is

Answer 34

processivity factor

Question 35

rolling-circle replication occurs

Answer 35

later in the infection

Question 36

U[30] and U[L]42 complex read both

Answer 36

inner and outer strands as leading strand synthesis and lagging strand synthesis, respectively

Question 37

like leading strand synthesis,

Answer 37

U[L]30 and U[L]42 displaces 5' part of own strand

Question 38

like lagging strand synthesis,

Answer 38

U[L]30 and U[L]42 is nicked and its 3'-end is extended by Pol U[L]30, and need helicase-primase

Question 39

[Gamma]-gene activation is made by

Answer 39

[Beta]-gene regulatory proteins or completion of replication

Question 40

[Gamma] proteins are

Answer 40

virion proteins and regulatory proteins

Question 41

Scaffolding proteins are

Answer 41

VP21, 22a, 24

Question 42

Major and secondary coat proteins are

Answer 42

VP5 and 26

Question 43

pac1 and pac2 in "a" region are

Answer 43

inserted into the immature preformed capsid

Question 44

terminase (UL6) mediates

Answer 44

packaging through portal

Question 45

insertion of progeny genome continues

Answer 45

up to next "a" region

Question 46

once complete,

Answer 46

conformational change seals capsid

Question 47

there are three models to

Answer 47

envelopment and engress of HSV

Question 48

model 1 illustrates

Answer 48

NC budding into the nuclear membrane, forming an envelope, exit as a vesicle budding, then secreted through vesicle fusion with plasma membrane

Question 49

model 2 illustrates

Answer 49

NC budding into the nuclear membrane, and exits, then enter through golgi membrane to form envelope, then secreted through vesicle fusion with plasma membrane

Question 50

model 3 illustrates

Answer 50

NC exiting through enlarged nuclear pore, forming envelope through entering in the golgi vesicle, then then secreted through vesicle fusion with plasma membrane

Question 51

virus latency occurs as

Answer 51

the virion losing most of VP16 on the way to neurons, remaining as dormant genome

Question 52

the dormant genome remains

Answer 52

as transcription factors in neurons Luman and Zhangfei bind to HCF-1, blcoking VP16 binding, consequently to prevent early-[alpha]-gene expression.

Question 53

the dormant genome requires

Answer 53

Oct-1 and HCF-1 to resurface to the skin or mucosal cells to be active