Cells inside our bodies divide constantly for growth and repair, but it’s a carefully controlled business. Mistakes can lead to diseases like cancer.
Researchers from Duke University School of Medicine have developed a sensor that reveals how cells maintain stability during this process. The sensor measures forces on motor proteins — tiny engines that help separate and organize chromosomes inside a structure called the spindle.
Working in fruit fly oocytes, or egg cells, the team found that a motor protein called kinesin-14 changes roles as division progresses: early on, it moves and detaches quickly; later, it locks in place to resist strong opposing forces.
“This is the first time that it has been possible to measure forces across a motor protein in cells undergoing division,” said Sharyn Endow, PhD, professor of cell biology and lead author of the work, published today in Current Biology. “Our studies produced unexpected findings that provide a new way of thinking about how division occurs in cells and the abnormalities that produce human disease, including cancers.”
The researchers’ measurements revealed that the forces borne by the motor protein were too large to be generated by the motor’s own activity. Instead, the results suggest kinesin-14 acts like an anchor within the spindle — binding and resisting other forces — to help keep chromosome separation on track.
“Understanding these forces could help design therapies that target cell division in disease,” Endow said.
“This is the first time that it has been possible to measure forces across a motor protein in cells undergoing division. Understanding these forces could help design therapies that target cell division in disease." — Sharyn Endow, PhD
The study was a collaboration among scientists in Duke’s Department of Cell Biology and Pratt School of Engineering, with partners at West Virginia University. The tension-sensing module used to create the new motor-protein sensors builds on technology originally developed by Brent Hoffman, PhD, in Pratt. Colleagues at West Virginia University performed tests to confirm that the engineered motor-protein sensors retain motor activity outside cells and are therefore highly likely to do so inside cells.
This work builds on a legacy of innovation at Duke. Decades ago, Bruce Nicklas, PhD, a renowned cell biologist in Duke’s Department of Biology who died in 2025, pioneered measurements of forces on chromosomes during cell division using glass needles. The new study extends the tradition of revealing the mechanics of life at the cellular level.
Other Duke University Authors: Kevin K. Do, Umika S. Paul, Zimiao Meng, Matthew Y. Wang.
Funding: National Institutes of Health, National Science Foundation, the March of Dimes.