Fundamentals of Cell Biology. Chapter 11: Signal Transduction and Cellular Communication. Chapter Summary: The Big Picture (1). Chapter foci: Structure of a signaling pathway Types of signals cells detect and the role of the receptor Molecules most commonly found in signaling pathways
Chapter 11: Signal Transduction and Cellular Communication
Figure 11.01: Simple schematic of signal transduction pathways.
Figure 11.02: Signaling pathways use linear, convergent, divergent, and branched signaling pathways to generate complex responses to external signals.
Figure 11.03: Receptors are grouped into six classes based on their structure and cellular location.
Figure 11.04: The general structure of a seven transmembrane receptor.
Figure 11.05: Model of growth factor receptor activation.
Figure 11.06: Serine/threonine kinase receptor activation leads to phosphorylation of a signaling protein.
Figure 11.07: Protein phosphatases break the phosphester bond linking phosphate groups to serine, threonine, and tyrosine side chains.
Figure 11.08: Receptor guanylyl cyclases are homodimeric receptors that contain a cytoplasmic domain that converts GTP into cyclic GMP.
Figure 11.09: Ligand-gated channels typically form a central pore that opens when a ligand binds to the receptor.
Figure 11.10: Integrin receptors form signaling scaffolds.
Figure 11.11: The steroid receptor binds to steroid hormones when they diffuse into the cytosol.
Figure 11.12: The GTPase cycle repeats continuously, shifting the G protein between active and inactive states like a switch.
Figure 11.13: A heterotrimeric G protein signaling cycle.
Figure 11.14: Protein kinases add phosphate groups to signaling proteins and effectors.
Figure 11.15: Lipid kinases add phosphates to phospholipids.
Figure 11.16: Calmodulin is an example of a calcium sensitive signaling protein.
Figure 11.18: Phosphodiesterase cleaves the phosphoester bond between the phosphate and the 3' carbon of ribose, converting cAMP to AMP.
Figure 11.17: Adenylyl cyclase is a target of competing regulatory pathways.
Ligand Gated Ion Channel
Hetero-trimeric G Proteins
Mono-meric G Proteins
Calcium Binding Proteins
What causes the α and βγ subunits of heterotrimeric G proteins to dissociate from each other?
a. Phosphorylation of the α subunit
b. Phosphorylation of the G protein-linked receptor
c. Phosphorylation of GEF
d. A change in shape in G protein linked receptors
e. Cleavage of GTP to GDP by the α subunit.
Figure 11.19: A simplified version of an FGF signaling pathway.
Figure 11.20: A sample cAMP signaling pathway.
Figure 11.21: The phosphoinositol 4,5-bis phosphate (PIP2) signaling pathway.
Figure 11.22: PIP2 phosphodiesterase and IP3 phosphatase inhibit PIP2 signaling.