Thanks.

My English is not so good.

I will try my best to let you know what I want to say.

This is my third time to attend the AOC meeting.

It's a very warm and lovely organization.

I really enjoyed it.

Thank all of the organizers.

Especially the beers.

I just changed the title a little.

I want you to know what we have done in the past 15 years.

AB signal pathway first introduction.

AB is short for abscisic acid.

It's one of the five plant hormones that play a very important role in anti-drought and seeding.

Before 2009, although many AB receptors have been reported, nine of them have been confirmed.

Until 2009, the PYL family was reported.

And during then, we are trying to elucidate the mechanism of AB receptor signal pathway.

At that time, we thought it was a membrane protein, but after publication, we found that it was a soluble protein.

From 2009 to 2012, we elucidated how AB receptors recognize AB.

After binding to AB, how PYL inhibits the inhibition of PP2C toward SIRK and releases kinase to activate the signal pathway.

First, we solved the using biophysical and biochemical method.

We solved the structure of PYL and AB.

And PYL, AB, PP2C, churnary structure.

And found that AB can break the dimerization interaction force of PYL.

So we used PYL without AB. It's a dimer with AB weakens the dimer and releases PYL from the dimer.

And the released PYL could bind to PP2C.

And then we also solved the structure of PP2C with SIRK.

This is a weak interaction. We do chimeric protein to link these two proteins together and solve the whole chimeric protein structure.

But these are not what I want to talk about today because this is AUC meeting.

After looking deep into this family, we found that there are 14 members of PYL family.

Using a chemical activity assay, we found that some family members can inhibit the inhibition of PP2C toward SIRK without AB.

Why is that? That's our question.

Without AB, PYL family also can inhibit the inhibition of PP2C.

Then we tried to use by chemical, you know, as you say, size exclusion chromatography to characterize the algal state of the protein.

And also use SIRS and AUC. We found that for the 14 members, all of the proteins we could purify is about 10 proteins.

4 proteins cannot be purified. For the 10 proteins, the first three are dimers.

The first six members exist as PYL3, very special. It exists as monomodimer intermediate. You will see from the SLS and AUC result.

But the other six members of the PYL family are always monomer in the solution.

And that's our autopsy result. We also tried to miss PYL family. The result is almost the same.

Then for PYL3, while it is intermediate, we know that we could calculate the self-association coefficient using some titration method.

This is protocol. After using that, we calculate the dissociation coefficient of PYL3 is about 2 micromolar.

You know that it's relatively immediate dissociation coefficient.

But after binding, after ideation of ABA, the small molecule, it weakened the interaction of the dimer to almost 100 micromolar.

This weakened release PYL. PYL competitively bind PYL3. Actually another means PYL competitively bind PYL.

And the PYL2 says the inhibition to SNRK was released. That's the activation of this signal pathway.

That's also not what I want to say today.

Overview of previous work, we have solved several structures and have published several papers about that.

But when we test the behavior of another protein, SNRK, it's a kinase. It's a very famous kinase in plant.

And it could phosphorylate a lot of transcription factor to activate the signal pathway, such as the seed dimension, seeding growth, right?

And the stress tolerance, a lot of stress, anti-stress gene will be expressed.

When we purify this protein, we actually during that time, we want to crystallize this protein and get structure.