This is a tardigrade I found under my microscope!
Imagine if we could preserve organs, slow the aging process, or protect astronauts from radiation in space!
Well, scientists are trying to make this a reality using these microscopic animals called tardigrades! These creatures have been alive long before the dinosaurs or the ice age, and are categorized as extremophiles because they can survive the harshest conditions imaginable. You know how you eat a mouthful of ice when it's hot, or use an umbrella when it's raining? Tardigrades have many processes in their body, each triggered by different hostile conditions. Like cryobiosis, which is triggered in extreme cold, and anoxybiosis, which is triggered when there is a lack of oxygen, and so on. Since there are quite a few processes, scientists use a general term, cryptobiosis.
But let's dig deeper into a specific process most commonly triggered in a tardigrade called anhydrobiosis, which occurs when their water levels drop. Their secret lies in their unique body, which consists of proteins that protect their cells.
More specifically, the tardigrade disordered proteins, which consist of CAHS, MAHS, and SAHS proteins. They have this special ability because they're made from amino acids — specifically hydrophilic (water-loving) amino acids — which means the proteins stay loose, like jelly, and flexible. When a tardigrade enters a harsh environment, the tardigrade's water levels decrease, and since the normal proteins need water for stabilization, they start to lose their structure. But before they unfold, the tardigrade disordered proteins layer the normal proteins with the TDPs. So essentially, the proteins are helping the proteins. Then vitrification occurs, the process of locking everything in place by changing the state to a hardened amorphous solid, essentially glass. From the start to the end of the process, this creature's metabolism decreases to almost 0, resulting in a state called the tun state. The tardigrade curls up into a ball and waits for water so it can wake up.
Now that you know what the proteins are made of, let's dig into what the protein functions are.
CAHS protein is located in the cell's cytoplasm, which is the thick fluid that surrounds the parts of the cell.
SAHS proteins are carried in a fluid secreted from inside the cell to coat the outside and protect the membrane, which protects the cell from the outside environment.
MAHS protein is believed to layer the mitochondrial membrane, which is in charge of forming adenosine triphosphate, or ATP — energy that's used to power the tardigrade.