WEBVTT
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If the message has arrived, it binds its receptor, and now something strange begins because the original messenger may still be outside of the cell.
00:01:09.759 --> 00:01:12.400
But inside, things start happening.
00:01:12.640 --> 00:01:15.039
Welcome to signal transduction.
00:01:15.679 --> 00:01:17.599
That sounds complicated.
00:01:18.319 --> 00:01:20.879
It actually is not that complicated.
00:01:21.120 --> 00:01:23.840
It really means something beautifully simple.
00:01:24.079 --> 00:01:28.239
The cell is converting one signal into another.
00:01:28.560 --> 00:01:30.400
Imagine a relay race.
00:01:30.560 --> 00:01:34.479
The first runner doesn't carry the baton all the way to the finish line.
00:01:34.640 --> 00:01:36.400
They hand it to someone else.
00:01:36.560 --> 00:01:39.759
And then who also that person hands it to somebody else.
00:01:40.000 --> 00:01:41.840
Who hands it to somebody else?
00:01:42.079 --> 00:01:45.120
Cells can do something similar with information.
00:01:45.599 --> 00:01:47.919
A receptor becomes activated.
00:01:48.079 --> 00:01:49.919
That affects another molecule.
00:01:50.159 --> 00:01:53.120
That molecule affects another and another.
00:01:53.439 --> 00:01:55.680
A signaling cascade begins.
00:01:55.919 --> 00:02:02.560
One of the ways cells control these proteins is through something called phosphorylation.
00:02:03.359 --> 00:02:11.280
I don't want you to worry so much about the terms, but what I hope you get out of it is a basic understanding of what's happening.
00:02:11.599 --> 00:02:20.719
A phosphate group can be added to a protein, and that small chemical modification can change what that protein does.
00:02:21.039 --> 00:02:25.599
Sometimes it activates it, other times it inhibits it.
00:02:25.840 --> 00:02:28.959
Sometimes it changes where that protein goes.
00:02:29.199 --> 00:02:37.519
And while we're at that, I do want to highlight that a lot of hormones, a lot of messages in our system come in the form of protein.
00:02:37.680 --> 00:02:50.879
So you can understand how important this is when we say once that message, which is now a protein, gets into the cell, that particular cell can choose to completely ignore it, it can choose to accept it, or it can choose to change it.
00:02:51.920 --> 00:02:57.759
Think of it less like an on and off switch and more like changing the settings on a piece of machinery.
00:02:57.920 --> 00:03:02.639
And that cell can add or remove these phosphate groups remarkably quickly.
00:03:02.959 --> 00:03:07.840
The enzymes that add them are called kinases.
00:03:08.400 --> 00:03:12.560
Remember that word, because we're going to meet a lot of kinases.
00:03:12.639 --> 00:03:17.520
And in fact, we've already met some in the mitochondrial series like AMPK.
00:03:18.000 --> 00:03:25.039
We're also going to talk about mTOR, AKT, and many other kinases.
00:03:26.000 --> 00:03:32.879
Reason we really want to talk about this is because they play a role in so many diseases and treatment molecules.
00:03:33.039 --> 00:03:42.560
For example, diabetes, cancer, inflammation, and growth depend heavily on phosphorylation.
00:03:43.680 --> 00:03:45.840
But don't memorize those names yet.
00:03:46.079 --> 00:03:48.879
For now, I would just want you to see the movie.
00:03:49.120 --> 00:03:54.960
Message, receptor, relay, protein changes, cellular response.
00:03:55.280 --> 00:04:01.759
Something that happened outside has been translated into biological action inside.
00:04:02.800 --> 00:04:12.079
But biology has another trick, because sometimes the original signal is tiny and the response is enormous.
00:04:12.639 --> 00:04:19.120
One hormone molecule can help trigger a cascade affecting many molecules downstream.
00:04:19.439 --> 00:04:22.159
The cell can amplify the message.
00:04:22.399 --> 00:04:30.879
And figuring out how that happened led one scientist to one of the great discoveries in hormbiology.
00:04:31.120 --> 00:04:34.560
We'll talk about that more in the next episode.
00:00:58.799 --> 00:01:09.519
If the message has arrived, it binds its receptor, and now something strange begins because the original messenger may still be outside of the cell.
00:01:09.759 --> 00:01:12.400
But inside, things start happening.
00:01:12.640 --> 00:01:15.039
Welcome to signal transduction.
00:01:15.679 --> 00:01:17.599
That sounds complicated.
00:01:18.319 --> 00:01:20.879
It actually is not that complicated.
00:01:21.120 --> 00:01:23.840
It really means something beautifully simple.
00:01:24.079 --> 00:01:28.239
The cell is converting one signal into another.
00:01:28.560 --> 00:01:30.400
Imagine a relay race.
00:01:30.560 --> 00:01:34.479
The first runner doesn't carry the baton all the way to the finish line.
00:01:34.640 --> 00:01:36.400
They hand it to someone else.
00:01:36.560 --> 00:01:39.759
And then who also that person hands it to somebody else.
00:01:40.000 --> 00:01:41.840
Who hands it to somebody else?
00:01:42.079 --> 00:01:45.120
Cells can do something similar with information.
00:01:45.599 --> 00:01:47.919
A receptor becomes activated.
00:01:48.079 --> 00:01:49.919
That affects another molecule.
00:01:50.159 --> 00:01:53.120
That molecule affects another and another.
00:01:53.439 --> 00:01:55.680
A signaling cascade begins.
00:01:55.919 --> 00:02:02.560
One of the ways cells control these proteins is through something called phosphorylation.
00:02:03.359 --> 00:02:11.280
I don't want you to worry so much about the terms, but what I hope you get out of it is a basic understanding of what's happening.
00:02:11.599 --> 00:02:20.719
A phosphate group can be added to a protein, and that small chemical modification can change what that protein does.
00:02:21.039 --> 00:02:25.599
Sometimes it activates it, other times it inhibits it.
00:02:25.840 --> 00:02:28.959
Sometimes it changes where that protein goes.
00:02:29.199 --> 00:02:37.519
And while we're at that, I do want to highlight that a lot of hormones, a lot of messages in our system come in the form of protein.
00:02:37.680 --> 00:02:50.879
So you can understand how important this is when we say once that message, which is now a protein, gets into the cell, that particular cell can choose to completely ignore it, it can choose to accept it, or it can choose to change it.
00:02:51.920 --> 00:02:57.759
Think of it less like an on and off switch and more like changing the settings on a piece of machinery.
00:02:57.920 --> 00:03:02.639
And that cell can add or remove these phosphate groups remarkably quickly.
00:03:02.959 --> 00:03:07.840
The enzymes that add them are called kinases.
00:03:08.400 --> 00:03:12.560
Remember that word, because we're going to meet a lot of kinases.
00:03:12.639 --> 00:03:17.520
And in fact, we've already met some in the mitochondrial series like AMPK.
00:03:18.000 --> 00:03:25.039
We're also going to talk about mTOR, AKT, and many other kinases.
00:03:26.000 --> 00:03:32.879
Reason we really want to talk about this is because they play a role in so many diseases and treatment molecules.
00:03:33.039 --> 00:03:42.560
For example, diabetes, cancer, inflammation, and growth depend heavily on phosphorylation.
00:03:43.680 --> 00:03:45.840
But don't memorize those names yet.
00:03:46.079 --> 00:03:48.879
For now, I would just want you to see the movie.
00:03:49.120 --> 00:03:54.960
Message, receptor, relay, protein changes, cellular response.
00:03:55.280 --> 00:04:01.759
Something that happened outside has been translated into biological action inside.
00:04:02.800 --> 00:04:12.079
But biology has another trick, because sometimes the original signal is tiny and the response is enormous.
00:04:12.639 --> 00:04:19.120
One hormone molecule can help trigger a cascade affecting many molecules downstream.
00:04:19.439 --> 00:04:22.159
The cell can amplify the message.
00:04:22.399 --> 00:04:30.879
And figuring out how that happened led one scientist to one of the great discoveries in hormbiology.
00:04:31.120 --> 00:04:34.560
We'll talk about that more in the next episode.
