Natriuretic Peptides

Question 1

What is the relationship of the NPs?

Answer 1

They all have a conserved ring structure but CNP looks as though it may be the primordial member.

Question 2

What are the different receptor types identified and their affinities?

Answer 2

Npr1 - (Guanylate cyclase A) - ANP»BNP»CNP
Npr2 - (GCB) - CNP»BNP>ANP
Clearance receptor (Ga(i)) ANP=BNP=CNP

Question 3

What do mutations of the CNP and (its receptor) genes lead to?

Answer 3

CNP - dwarfism
GCB - female sterility and dwarfism
Clearance receptor - gigantism.

Question 4

Where is CNP expressed and what is its relationship to GnRH?

Answer 4

Gonadotroph cells in the AP. GnRH inhibits cGMP accumulation due to CNP and CNP inhibits GnRH stimulated calcium accumulation. It also seems to affect gonadotroph gene expression, pituitary development(zebrafish).

Question 5

How can CNP be studied?

Answer 5

Look at pathology of KOs or mutants

Sequence the gene to see how well it is conserved between species and which genes to look at in lower species

Look at expression profiles in zebrafish (spatial and temporal)

Give exogenous CNP to see how this might affect gene expression

Transgenics that overexpress CNP
- tissue specifics

Question 6

What is morphino silencing?

Answer 6

Using RNA to silence genes.