Question

Research and describe a cell receptor involved in cell signaling that utilizes one of the following mechanisms.

1. RTK pathway (Receptor Tyrosine Kinase Cascade)

2. GPCR (G Protein Coupled Receptor)

3. Ion Channel Receptors

4. Ligand Gated

Your summary of the protein receptor must include the following:

1. Name of the receptor and its ligand.

2. A brief description of the pathway (what is activated and how).

3. Name of the pathway it is responsible for activating and what the pathway response is. (What is the cell response).

4. Is the pathway associated with the development of cancer?

5. What type of receptor is it? (Should be one of the four listed above).

Answer 1

Receptor Tyrosine Kinase (RTK)

These are cell surface receptors for polypeptide growth factors, cytokines, and hormones. Binding of growth factor to the extracellular domain of an RTK leads to its dimerization.This then activates proteins cytoplasmic kinase domains.The receptor is activated by autophosphorylation of specific intracellular tyrosine residues. This inturn activates Sh2 and PTB domains. Epidermal growth factor receptor is a family of receptor tyrosine kinase. excessive erb2 signalling is associated with development of solid tumors.

G Protein coupled receptor

They are found in eukaryotes, yeast and animals.They are seven transmembrane domain receptors. The examples are cAMP and Phosphotidyl inositol signalling. G protein is active when the GTP is bound to it and inactive when GDP is bound. In cAMP signalling, the adenylase cyclase coverts AMP to cAMP. cAMP then activates protein kinase A

Ion channel receptors are cell membrane bound receptors. They are mainly present on synaptic structures.Excitation of presynaptic neuron cause release of neurotransmitter that bind to post synaptic neurons and opens the ion channels.example - N-methyl-D-aspartate receptor (NMDA receptor), NMDA bind to NMDA receptor and activate the receptor to open cation channel.