Motor proteins are tiny molecular machines that convert chemical
energy into mechanical work. They are the miniature "vehicles" of a
cell, and move on a network of tracks commonly referred to as the
cytoskeleton. They shuttle cellular cargos between locations and
generate forces to position chromosomes.
But in spite of intensive
research efforts over many years, mechanisms underlying the actions of
many motor proteins are still unclear.
‘A new understanding of the complex cellular machinery that animal and fungi cells use to ensure normal cell division has been offered by a study.’
A study published today offers a new understanding of the complex
cellular machinery that animal and fungi cells use to ensure normal cell
division, and scientists say it could one day lead to new treatment
approaches for certain types of cancers.
The research revealed a totally unexpected behavior about a "motor"
protein that functions as chromosomes are segregated during cell
division. The findings were published in Nature Communications
The work was led by Weihong Qiu, an assistant professor of physics
in the College of Science at Oregon State University, in collaboration
with researchers from Henan University in China and the Uniformed
Services University of the Health Sciences in Maryland.
In this study, researchers 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 on the
cytoskeleton track. They discovered that KlpA is able to move in
opposite directions - an unusual finding. KlpA-like motor proteins are
thought to be exclusively one-way vehicles.
The researchers also discovered that KlpA contains a gear-like
component that enables it to switch direction of movement. This allows
it to localize to different regions inside the cell so it can help
ensure that chromosomes are properly divided for normal cell division.
"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
"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
Qiu and colleagues 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
"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."