Alternative Approaches to Studying ATP Signaling in Root Hairs

1
Alternative Approaches to Studying ATP Signaling
in Root Hairs

• Discovery Lab Lecture
• March 20, 2007

2
Until now we have used selected chemicals to
clarify how root hair growth is regulated

• Chemicals tested before Spring break include
• ADP?S
• GTP?S
• apyrase inhibitor
• DPI

3
Calmodulin as a potential mediator of nucleotide
effects

• Calmodulin (CaM) is a calcium-binding protein, is
  activated by calcium.
• Activated CaM binds to and activates a variety of
  different enzymes
• NADPH oxidase, which promotes superoxide
  production, is a calmodulin-activated enzyme
• Some key protein kinases are calmodulin-activated
  enzymes
• eATP/eADP induce an increase in Ca2cyt
• If CaM mediates eATP/eADP effects, CaM
  antagonists could block these effects.

4
Washing hairs as an approach to further test
effects of low eADP?S

• Growing root hairs release eATP.
• Removal of this naturally released eATP lowers
  the eATP
• Effects of exogenously-added eADP?S can be more
  easily interpreted if exogenous eATP is first
  removed by washing.

5
Today

• Plant seeds for next weeks experiment
• Look ahead to Round 4 (TWO experiments)
• Discuss FRI summer research program FRI
  outreach program