Li Tao, Assistant Professor of Biology

Assistant Professor Tao is investigating mechanisms of cell division to provide clues for cancer treatment. His ultimate goal is to find an effective way to cure cancer.

Li Tao is an assistant professor of biology at the University of Hawai‘i at Hilo. He is a biochemist and a cell biologist with expertise in using a combination of in vitro biochemistry and in vivo cell biology to understand the regulation of cell division, thus providing insights into the fundamental mechanism to control the growth of cancer cells.

He received his doctor of philosophy in biochemistry and molecular biology from the University of California at Davis, and his master of science in physiology from Nanjing University. He arrived at UH Hilo in 2014.

“Understanding the mechanism of cell division and its control is the key to find cures for cancer,” Tao explains. “Cells use kinesins, a subfamily of mitotic motors, to drive cell division. My research is primarily centered on various kinesins and explores how these motors regulate cell division. By developing conditions to stably express full-length kinesin motor proteins, we explore the mechanisms driving the formation and functioning of the mitotic spindle.”

Cytokinesis is the final stage of cell division, hence, says Tao, it is the last chance for the cell to perform “quality control.” Any mistakes that escape from cytokinesis will cause severe human diseases including cancer. Recently, Tao found that a key motor protein for cytokinesis, kinesin-6, is regulated by Rho-family protein RacGAP.

“Originally, the widely accepted concept in the field is that all kinesins can move along microtubules by themselves,” he says. “However, we found that kinesin-6 alone is not active, meaning it cannot move on microtubules. Kinesin-6 has to bind to another protein RacGAP to activate its function. This finding provides a novel mechanism on the regulation of cytokinesis.”

The results were published as a research article in Nature Communications (April 19, 2016) with Tao as both lead author and corresponding author: Tum/RacGAP functions as a switch activating the Pav/kinesin-6 motor.

Tao and his research team are continuing their study on kinesin-6 and other motor proteins.

“We want to perform structural analysis on these kinesins and identify the potential molecular targets for anti-cancer drugs,” he says.

The team also plans to use purified kinesin proteins to reconstitute mitosis. Tao says this system, once established, will be a breakthrough to the field and open new avenues for the study of cell division.

Two students,  Gin Tezuka and Luke Kupcha, are working with Tao on these projects.

According to the National Cancer Institution, there will be more than 1.6 million new cases of cancer in the United States in 2016, and the national cost of cancer care could reach $156 billion in 2020. Finding cures for cancer is in the national interest and is urgently needed to relieve human suffering and reduce economic costs.

Tao says his research into the mechanisms of cell division will provide clues for cancer treatment.

“Abnormal cell division causes cancer,” he explains. “Understanding the mechanism of cell division and its control has thus become a key to find cures for cancer. My study is directly related to the regulation of cell division.”

Tao’s ultimate goal is to have a greater understanding of how mitotic motors regulate cell division, and to find an effective way to cure cancer.

“In my opinion, solving problems on cell division should be teamwork with experts from various fields,” he says.

He is collaborating with Professor William Sullivan at University of California, Santa Cruz, to explore the mechanism of cytokinesis. He also is seeking collaborations with structural biologists, biophysicists and mathematicians to characterize the kinesin motor’s structures and function.

Above, centralspindlin, a key motor complex for cytokinesis, moves polarity-marked microtubules in vitro. Video by Li Tao.

 

By Susan Enright, public information specialist, Office of the Chancellor. Photos by Claudia Hagan.

Originally published on April 26, 2016, and updated on April 17, 2018.