Study reveals bidirectional movement of "motor" protein

Researchers have discovered what they say is an unexpected behavior about a "motor" protein as part of the complex cellular machinery that animal and fungi cells use to ensure normal cell division.

Motor proteins, or tiny molecular machines that convert chemical energy into mechanical work, are the miniature "vehicles" of a cell moving on a network of tracks commonly referred to as the cytoskeleton and shuttling cellular cargos between locations and generate forces to position chromosomes.

In a study published Wednesday in Nature Communications, Weihong Qiu, an assistant professor of physics in the College of Science at Oregon State University (OSU), and his colleagues focused on a particular motor protein, called KlpA, and used a high-sensitivity light microscopy method to directly follow the movement of individual KlpA molecules.

They discovered that KlpA motor proteins, once thought to be exclusively one-way vehicles, are able to move in opposite directions.

"KlpA is a fascinating motor protein because it is the first of its kind to demonstrate bidirectional movement," Qiu said. "It provides a golden opportunity for us to learn from Mother Nature the rules that we can use to design motor protein-based transport devices. Hopefully in the near future, we could engineer motor protein-based robotics for drug delivery in a more precise and controllable manner."

In addition, the research team, including members from Henan University in China and the Uniformed Services University of the Health Sciences in Maryland on the U.S. east coast, discovered that KlpA contains a gear-like component that enables it to switch direction of movement, allowing it to localize to different regions inside the cell so it can help ensure that chromosomes are properly divided.

"In the past, KlpA-like motor proteins were thought to be largely redundant, and as a result they haven't been studied very much," Qiu was quoted as saying in a news release from OSU in the U.S. Pacific Northwest. "It's becoming clear that KlpA-like motors in humans are crucial to cancer cell proliferation and survival. Our results help better understand other KlpA-like motor proteins including the ones from humans, which could eventually lead to novel approaches to cancer treatment."

The researchers say they are excited about their future research, which may uncover the design principle at the atomic level that allows KlpA to move in opposite directions, and there may be other applications. Endit