Hiv

Front 1

Most HIV-1 patient isolates belong to what antigenic group?

Back 1

Group M

Front 2

What clade do most HIV-1 patients belong to?

Back 2

Clade C

Front 3

What is the HIV surface protein responsible for serving as ligand or host cell receptor?

Back 3

gp120

Front 4

What is the HIV transmembrane protein that mediates fusion of virus envelope with host cell membrane?

Back 4

gp41

Front 5

M trophic infxn focuses on __________, whereas T trophifc infxn focuses on_______.

Back 5

macrophages
T cells

Front 6

What is a polymerase that converts + sense ssRNA to DNA?

Back 6

Reverse Transcriptase (RT)

Front 7

What does RT use as a primer?

Back 7

host cell lysine-charged tRNA

Front 8

What degrades the RNA template during HIV replication?

Back 8

RT RNase H site

Front 9

What makes up the pre-integration complex?

Back 9

Viral DNA
NC
Vpr
Integrase
MA

Front 10

What facilitates RT by protecting the complex in nuclear transport and helps keep cells in resting cell cycle?

Back 10

Vpr - Viral Protein R

Front 11

What are 4 charac. of Long Terminal Repeats (LTRs)?

Back 11

1. Enhancer and Promoter Sequences for host proteins (TF binding sites)
2. Recruitment sites for host RNA poy II
3. has TAR (transactivating response element that will bind HIV Tat)
4. 3' end has polyadenylation signal

Front 12

What makes 2 sticky ends, helps enter nucleus, and helps enter host genome?

Back 12

Integrase

Front 13

What are the regulatory proteins made in the early phase of HIV gene expression?

Back 13

Tat, Rev, and Nef

Front 14

How does Tat regulate HIV gene expression?

Back 14

If Tat and cyclinT1 bind to TAR than Cdk9 is activated, leading to phosphorylation of C-terminal domain of RNA poly I and you get ELONGATION!!!! so Tat stimulated elongation

Front 15

What happens in absence of Tat on HIV gene expression?

Back 15

than ineffective RNA poly II elongation and you get aborted transcription

Front 16

What is the function of Rev in HIV replication?

Back 16

functions to transport UNSLICED and SINGLY spliced mRNAs across the nuclear membrane

Front 17

Rev binds to what to mediate export of mRNA from the nucleus to the cytoplasm?

Back 17

REE- Rev Response Element

Front 18

What is involved in generation of proteins from polyproteins?

Back 18

Protease- vital for HIV maturation!

Front 19

Protease cuts what?

Back 19

Gag polyprotein into 3 segments:
MA
CA
NC

Front 20

____________ results in correct orientation of nucleocapsid and matrix to allow for successful uncoating upon binding to uninfected host cells.

Back 20

Proteolytic cleavage

Front 21

What targets new CD4 molecules for destruction?

Back 21

Vpu- Viral Protein U.

Front 22

What has a binding site for E3 ubiquitin ligase and directs ubiquination of CD4?

Back 22

Vpu

Front 23

What are the 3 main fxn of Nef?

Back 23

1. promotes apoptosis of responding CTL
2. Inhibits apoptosis of infected host cell
3. Nef mediates MHC class I and CD4 downregulation

Front 24

How does Nef inhibit apoptosis of infected host cell?

Back 24

1. binds ASK1 and blocks Fas and TNFR signals.
2. binds p53
3. induces PAK, so phosph. BAD, and thus releases bcl-2/bclX1 to prevent apoptosis

Front 25

What is Nef's role in mediating MHC class I?

Back 25

binds to MHC Class I and causes it to end up being trapped in Trans Golgi Network (TGN)

Front 26

What is Nef's role in CD4 downregulation?

Back 26

Nef triggers for CD4 to be endocytosed, travels via endosome, and thus is translocated to lysosome for degradation

Front 27

APOBEC promotes mutations to reduce viral gene expression. What does HIV virus do to stop this?

Back 27

Vif (VIral Infectivity Factor) bind to APOBEC and mediates interaction with ubiquinase. It is then degrades by the proteosome.

Front 28

What are 5 reasons why immunity fails to clear HIV?

Back 28

1. gene variation
2. escape CTL and NK cell cytotoxity
3. Induce T cell apoptosis
4. induce production of suppressive cytokines
5. prevent DC maturation

Front 29

What are 2 mechanisms HIV uses for Genetic Variation?

Back 29

1. High Mutation Rate of RT
2. Recombination when more than one virus infects a cell

Front 30

HIV infects cells expressing both CD4 and either ____________ (M tropic) or _____________ (T tropic).

Back 30

CCR5- M- tropic
CXCR4- T-tropic

Front 31

What facilitate transloaction of the viral cDNA to the nuclear pore complex for nuclear localization?

Back 31

MA and Vpr

Front 32

What mediates transactivation of the viral genome?

Back 32

Tat

Front 33

What mediates rapid transport of viral mRNA out of the nucleus?

Back 33

Rev

Front 34

What protects the infected cell from lysis by immune cells as well as inhibiting apoptosis?

Back 34

Nef

Front 35

Activated cells express transcription factors which then combine with __________ to promote viral synthesis.

Back 35

Tat

Front 36

All of the viral proteins are synthesized and assembly occurs at _____________ where gag envelopes the nucleocapsid and pushes thru the membrane to bud off the host cell.

Back 36

at the host cell membrane