A team led by Rutgers University researchers have figured out how cells deploy enzymes to control traffic along cellular highways. The work was published yesterday in Current Biology.
"To stay alive and function, every cell in our body needs to transport cargoes to the place they're needed inside the cell, in the right amount and at the right time," said Robert O'Hagan, lead author of a new study. "So there has to be a lot of organization in how transport inside the cell is regulated, and now we know a lot more about how that happens."
O'Hagan notes that the highways inside cells are called microtubules and the cargo trucks in cells are kinesin and dynein proteins. So the researchers wondered, how is the transport system organized within a cell?
Using Caenorhabditis elegans, the team looked at microtubules in cilia and found that enzyme TTLL-11 acts as a traffic regulator, posting signs of amino acid glutamate to regulate the protein cargo trucks. They also found that CCPP-1 is an enzyme that takes down these glutamate traffic signs when there are too many of them. In addition, the glutamates could also act as a "roadway under construction" sign, changing the highways' structure.
Interestingly, according to O'Hagan, these enzymes are involved in degenerating cells that are crucial for vision, as well as neurons. "The picture that's emerging from our and other labs' research is that, for neurons to regenerate after injury or to survive in the brain, they need to be able to reorganize their microtubular highways and their cargo trucks in order to bring the right cargoes around to rebuild or maintain the cell," he said.
"There's a lot more to be discovered," he added. "Our next step is to see how this works in the spinal cord in mammals, so we've started studies of rat spinal cord neurons."
Image: How cellular highways work. Image courtesy of Robert O'Hagan/Rutgers University-New Brunswick.