Enzyme-Linked Receptors

Question 1

What is the collective term for the signal proteins that illicit differentiation and proliferation of a cell?

Answer 1

Growth factors!

Question 2

In what time scale do these enzyme-linked receptors mediate a change in gene expression? ⏳

Answer 2

In the magnitude of several hours

Question 3

To what cellular responses were enzyme-linked receptors initially found to be responsible for?

Answer 3

Cell growth, proliferation, differentiation, and survival

Question 4

What other cellular responses are ELRs responsive for?

Answer 4

ELRs also directly mediate changes in the cytoskeleton; governing the movement and shape of the cell

Question 5

What class of disease are associated with erroneous ELRs and/or their intracellular secondary messengers

Answer 5

Cancer, as mutations to the components of these signalling pathways lead to uncontrolled cell proliferation and movement (metastasis)

Question 6

Describe the basic structural features of a ELR

Answer 6

Typically single pass TM subunit, unlike GPCRs 7 pass TM fold
Extracellar ligand binding domain
Intracellular domain either possess intrinsic enzymatic activity or associates directly with intracellular enzyme

Question 7

What are the six major classes of ELRs? (Hint: Lasting Growths)

Answer 7

Lasting Growths

L: receptor-like tyrosine phosphatase
G: receptor gyanylyl cyclase 
R: receptor tyrosine kinase 
T: tyrosine-kinase associated receptor
H: histidine kinase associated receptor
S: receptor serine/threonine receptor