FoldIt is an online game in which humans try to solve one of the hardest computational problems in biology: protein folding. You don't need to know anything about biology to play the game, although a little background will help. Most of the players of foldit are not biologists.
How does my game playing contribute to curing diseases?
With all the things proteins do to keep our bodies functioning and healthy, they can be involved in disease in many different ways. The more we know about how certain proteins fold, the better new proteins we can design to combat the disease-related proteins and cure the diseases. Below, we list three diseases that represent different ways that proteins can be involved in disease.
- HIV / AIDS: The HIV virus is made up largely of proteins, and once inside a cell it creates other proteins to help itself reproduce. HIV-1 protease and reverse transcriptase are two proteins made by the HIV virus that help it infect the body and replicate itself. HIV-1 protease cuts the "polyprotein" made by the replicating virus into the functional pieces it needs. Reverse transcriptase converts HIV's genes from RNA into a form its host understands, DNA. Both proteins are critical for the virus to replicate inside the body, and both are targeted by anti-HIV drugs. This is an example of a disease producing proteins that do not occur naturally in the body to help it attack our cells.
- Cancer: Cancer is very different from HIV in that it's usually our own proteins to blame, instead of proteins from an outside invader. Cancer arises from the uncontrolled growth of cells in some part of our bodies, such as the lung, breast, or skin. Ordinarily, there are systems of proteins that limit cell growth, but they may be damaged by things like UV rays from the sun or chemicals from cigarette smoke. But other proteins, like p53 tumor suppressor, normally recognize the damage and stop the cell from becoming cancerous -- unless they too are damaged. In fact, damage to the gene for p53 occurs in about half of human cancers (together with damage to various other genes).
- Alzheimer's: In some ways, Alzheimer's is the disease most directly caused by proteins. A protein called amyloid-beta precursor protein is a normal part of healthy, functioning nerve cells in the brain. But to do its job, it gets cut into two pieces, leaving behind a little scrap from the middle -- amyloid-beta peptide. Many copies of this peptide (short protein segment) can come together to form clumps of protein in the brain. Although many things about Alzheimer's are still not understood, it is thought that these clumps of protein are a major part of the disease.
We’re collecting data to find out if humans' pattern-recognition and puzzle-solving abilities make them more efficient than existing computer programs at pattern-folding tasks. If this turns out to be true, we can then teach human strategies to computers and fold proteins faster than ever!