Lecture 3 - Influenza and PHA

Question 1

Influenza virion contains…

Answer 1

genetic sequences for glycoproteins

Question 2

Haemagglutinin

Answer 2

binds to silica acid residues to activate PKC and transient inhibition of ENaC

Question 3

M2

Answer 3

forms an acid-activated, amantadine-inhibited H+ channel, inserted into the apical membrane host cell

Question 4

M2 is involved in…

Answer 4

long term ENaC regulation

Question 5

M2 overexpression

Answer 5

reduction in channel number. Control shows two channels opening but this shows only one

Question 6

ENaC alpha and beta subunits in M2

Answer 6

both reduced in presence therefore reduced channel number

Question 7

ENaC current at M2 overexpression

Answer 7

reduced

Question 8

M2 over expression and endocytosis in Liddle’s patient

Answer 8

in mutant endocytosis is reduced but not to the same extent as control, endocytosis is occurring as otherwise currents would disappear

Question 9

Ros and M2 absence

Answer 9

no to little Ros

Question 10

Ros and M2 overexpression

Answer 10

lots of Ros and colocalisation of Ros and M2

Question 11

GSH

Answer 11

antioxidant reversing M2 inhibition which proves M2 overepxression increases Ros levels

Question 12

G-6796 and inhibitor

Answer 12

different PKC isoform inhibitors, shows inhibition reversal. M2 overexpression shows increased PKC

Question 13

Why is the literature conflicted about flu?

Answer 13

different papers say increased or decreased ASL.

Question 14

What could be potential reasons for literature conflict>

Answer 14

cell source
influenza virus properties
lab conditions
or this could actually be what occurs in vivo

Question 15

what is forskolin used for?

Answer 15

measuring CFTR function

Question 16

why are there two bands of CFTR?

Answer 16

one band represents immature channels

Question 17

What is the mature CFTR?

Answer 17

band 3, the only ones that function

Question 18

Mature CFTR and M2

Answer 18

when over expressed there is reduced mature CFTR in the whole cell and PM

Question 19

DsiM2

Answer 19

M2 knockdown

Question 20

Why is DsiScram used?

Answer 20

as a control

Question 21

infected cells and DsiM2

Answer 21

show inhibition in both control and M2 KD - inhibition exclusively mediated by M2

Question 22

Infected cells and M2 inhibition

Answer 22

CFTR currents return to normal

Question 23

Udorn virus M2 aman-sensitive

Answer 23

blocks H+ function

Question 24

M2 and pH

Answer 24

M2 mediates H+ movement therefore changing the pH and targets CFTR for lysosomal degradation

Question 25

Bafilomycin

Answer 25

prevents lysosomal acidification

Question 26

Lactacystin

Answer 26

prevents proteosomal degradation

Question 27

ENaC gain of function mutations (4)

Answer 27

Liddle’s syndrome
hypertension
increased ENaC
Nedd4 channel retrieval

Question 28

ENaC loss of function mutations (2)

Answer 28

PHA (Pseudohypoaldosteronism)

ENaC inactivation

Question 29

Pseudohypoaldosteronism results in…

Answer 29

salt wasting
hypotension
hyperkalaemia
metabolic acidosis
high renin and aldosterone

Question 30

PHA is genetically…

Answer 30

autosomal recessive

Question 31

PHA affects…

Answer 31

multiple organs

Question 32

In PHA all ENaC…

Answer 32

subunits are mutated

Question 33

PHA symptoms

Answer 33

frequent lower RTI, permanent runny nose due to increased nasal liquid and blockages in nasal passages, excessive sodium in nasal discharge consistent with ENaC inhibition

Question 34

Vte in PHA

Answer 34

reduced