1. Cell Communication
Chapter 9

2. Cell Communication Ligand Receptor Protein
Cells select what signals to respond to

4. Signaling depends on distance
Direct Contact
Paracrine
Endocrine
Synaptic
Autocrine

6. Signal Transduction
The events that occur within the cell on receipt of a signal
Differ from cell to cell
Phosphoralation and Dephosphorolation
Protein Kinases
Phosphatases

7. Types of Receptors
Intracellular
Cell Surface
Membrane Receptors

8. Types of Membrane Receptors
Channel Linked- chemically gated
Enzymatic Receptors
G-Protein- Coupled- used second messengers such as cAMP and calcium

9. G-Protein

10. Intracellular Receptors
Found inside of cell
Lipid Soluble molecules use them…Like what?

11. Receptor Kinases Phosphorylate proteins to alter function
Can attribute to cancer
RTK’s single transmembrane

12. Insulin Receptor

13. Signal Cascades

14. Scaffold Proteins and RAS proteins
Organize Kinase Cascade in the cytoplasm
RAS links the RTK’s with the kinase cascades

15. Deactivation of RTK’s
Dephosphorylation
Internalization

16. G-protein coupled Receptors (CPCRs)
In its on state it activates the effector proteins to cause cellular response

17. Effector Proteins cause secondary messengers
cAMP- activates the enzyme protein kinase which adds phosphates to specific proteins.
If deficient can cause cholera
IP3- can also activate protein kinase
Calcium-very versatile
Different Receptors can produce the same second messenders

18. G-Protein Coupled Receptors and Tyrosine Kinase receptors can activate the same pathways…
Why is this beneficial?

19. Cell to Cell Interactions
Surface Proteins Give Cells Identity
Cell connections mediate cell to cell adhesion

20. Surface Proteins
Glycolipids
ABO blood types
MHC proteins

21. Cell Connections Cell-Junctions- permanent connections
Tight Junctions…where found?
Anchoring Junctions
Cadherin and actin and intermediate filaments
Integrin-mediated
Adherins- connect actin to actin or to ecm- linking junctions called integrins
Communicating Junctions
Gap Junctions
Plasmodesmata