Study finds proteins precisely control direction of cell movement

South Korean researchers have, for the first time worldwide, uncovered the mechanism by which cells move during processes such as cancer metastasis, when cancer cells spread to other parts of the body, or immune cell migration during wound healing.

On Nov. 10, KAIST announced that a research team led by Heo Won-do, distinguished professor in the Department of Biological Sciences, in collaboration with Jo Kwang-hyun of the Department of Bio and Brain Engineering and Lee Gap-sang at Johns Hopkins University, had identified a “self-driving mechanism” that allows cells to autonomously determine their direction of movement without external signals. The study was published in the international journal Nature Communications on Oct. 31.

The team developed a new imaging technology called INSPECT, which allows researchers to observe how proteins interact within cells. Using the technology, they monitored key proteins known as Rho family proteins, which regulate cell movement. They found that these proteins not only separate the front and rear of a cell, as previously understood, but also determine whether a cell moves straight or changes direction depending on which proteins they bind.

The researchers analyzed 285 interactions by combining 15 types of Rho proteins with 19 binding proteins. Of these, 139 pairs actually formed interactions. They discovered that the Cdc42-FMNL combination drives cells to move straight, while Rac1-ROCK controls directional changes. When the team modified part of the Rac1 protein to prevent it from binding to the ROCK protein, which acts as a “handle,” the cells could not change direction and continued moving in a straight line.

Heo said the study shows that cell movement is not random but is precisely controlled by the binding of Rho proteins with other proteins. He added that the INSPECT technology could help reveal molecular mechanisms behind various biological processes and diseases, including cancer metastasis and neural cell migration. The research was supported by the Samsung Future Technology Foundation and the National Research Foundation of Korea.


최지원 기자 jwchoi@donga.com