1. Signal
Transduction
Pathways

2. Signaling Pathways Control Many Cellular Processes
Cell Shape
Cell Polarity
Cell Cycle
Development ….. and Disease

3. Signals
Stop!
……….Pathway OFF
Go Faster?
….…Basal
Go.
……..Pathway ON

4. Generic MAP Kinase Pathway
Stimulus
Receptor
PAK/G-protein
MAP Kinase
Cascade
Txn Factors

5. Budding Yeast is a Model Organism
Yeast Genetics
Genomic Screens
Genomics
DNA Microarrays
Cell Biology
GFP Collection
Biochemistry
TAP Tag Collection
Genetics and High-throughput Technologies

6. Filamentous Growth (FG) in Yeast
Saccharomyces cerevisiae
FG is required for fungal pathogenesis.

7. MAPK Pathways Share Factors
HOGP
Sho1
Ste20/Cdc42
Ste11
Pbs2
Hog1
Hot1
FGP ?
Ste20/Cdc42
Ste11
Ste7
Kss1
Ste12/Tec1
FGP
Sho1 + ?
Ste20/Cdc42
Ste11
Ste7
Kss1
Ste12/Tec1
PRP
Ste2/3/4/18
Ste20/Cdc42
Ste11
Ste7
Fus3
Ste12
Ste5

8. Genome-Wide Genetic Screen
Mutants defective for agar-invasion (FG)

9. DNA Microarray AnalysisUP
NO CHANGE
DOWN

10. Comparison of Genomic Data
MSB2 was identified in both screens.

11. Scaffold at the Head of the FG Pathway
Mucin Domain
Msb2
Cdc42
Sho1

12. Role of Mucin Domain in Signaling
Mucin domain is inhibitory.
FUS1-lacZ
N…(698)S Q V S D T S
V S Y T T S S S S V S Q V S D T P
V S Y T T S S S S V S Q V S D T S
V P S T S S S S S V S Q V S D T P
V P S T S S S S S V S Q (818) …C

13. Hyperactivity
Go, Go, Go!

14. Questions about the FG pathway
What is Msb2 sensing?
How are general factors specified by Msb2?
In what other ways is specificity achieved?

15. Negative Regulation
Stop!

16. Novel Negative Regulator: a Calmodulin Kinase
HOGP
Sho1
Ste20/Cdc42
Ste11
Pbs2
Hog1
Hot1
FGP
Sho1 + Msb2
Ste20/Cdc42
Ste11
Ste7
Kss1
Ste12/Tec1
Rck2

17. Questions about Rck2 Where does the kinase act?
How does P~lation by Rck2 cause pathway shut-off?
Is the response specific?

18. Rotate in Paul Cullen’s Lab?
Sure!

19. Training in Paul Cullen’s Lab
Question-based approach
Learn many different techniques (Genomics)
Working with yeast is Fun!