Part 1: The building blocks of life
Professor Yvonne Jones is director of the Cancer Research UK Receptor Structure Research Group. Her research focuses on the structural biology of cell surface recognition and signalling complexes. Receptors embedded in the surface are potential targets for therapeutic intervention in many diseases including cancer.
Jonathan Webb: Our bodies are made up of trillions of cells, but no matter how closely you look, you still won't see them. In fact, most of our cells are smaller than the width of a hair. Now, for our bodies to work properly, all our cells have to talk to each other, which is a big ask for a little guy. So how do our cells communicate?
The word protein might maybe think of your Sunday chicken dinner, or have the powdered shakes that athletes drink after a tough workout. In fact, proteins are tiny machines working inside our cells, and as well as many other jobs for the body, proteins help our cells communicate. Sometimes cells need to communicate over large distances, a little bit like sending a letter in the mail.
Yvonne Jones: Obviously, cells don't read and write. Instead, they use the language of shape; the messenger comes in and has to be recognised very specifically, by one of many different sorts of receptors on our cell surface. It's as though it's been delivered to the right letterbox I guess. And when it does that binds to it, transmits a signal into the cell, which can tell the cell to multiply, or to move, and sometimes to die all the time ways of giving cells instructions.
Jonathan Webb: Just like your body has trillions of cells, every single cell contains billions of proteins, sending and receiving signals, and doing all the cells other jobs as well. That's more proteins inside every single cell than there are blades of grass on 10 football fields.
These tiny protein machines vary in shape, as well as in function. They're each built from a long chain of 20 different amino acids, a little bit like the beads on a necklace. The sequence of those amino acids means that each one falls into a distinct three-dimensional shape.
The resulting shape defines the function of that protein. And all of these different proteins within the body have their own job to do. Some are involved in structural support, and body movement. Others help us fight off germs.
You might have heard of keratin, for example, keratin is a structural protein; it strengthens the protective coating in our hair, or in the horns of a bull, or in the feathers of a bird. Protein enzymes carry out most of the chemical reactions in our metabolism. Other enzymes are involved in manipulating our DNA, copying it, repairing it, and transcribing genes to make new proteins.
So there are many, many proteins doing an awful lot of work inside my body right now. And all of these very different functions are happening simultaneously. All of these proteins in all of the cells whizzing off signals to make sure that the right tasks are done in the right place at the right time.
Yvonne Jones: It can go wrong, and one of the times that it goes wrong is in cancer. Because the thing about cancer cells is that, they are doing the wrong thing in the wrong place at the wrong time. So they start multiplying up, there is an instruction sent out that that cell should die. They ignore it. Then they start invading other environments. So moving to other tissues. So obviously, the more we can learn about how normally cells communicating, and then how the cancer cells are ignoring the right instructions, and issuing the wrong instructions, we can go in with our own shape, and try and turn off the cancer cells issue a different sort of instruction. We can learn to do all of that if we understand this language of the shapes. And, that’s how some cancer treatments already work.
Jonathan Webb: By using modern technology to determine their structure, scientists can pinpoint the exact part of a protein to target with drugs. But how far has that technology come over the years? How did we get here?