Researchers have recently developed a molecular sensor that can identify cancer drugs by detecting how such chemicals modify microtubules inside living cells, said the Ministry of Science and Technology on 16th March.

Microtubules are part of the cytoskeleton, a structural network within the cell's cytoplasm, and they alter in response to several chemicals. Understanding tubulin modifications has remained a challenge to date because of the unavailability of tools that can mark them in living cells. This work has been recently published in the Journal of Cell Biology.

The researchers from the Institute for Stem Cell Science and Regenerative Medicine (inStem) in Bengaluru and Curie Institute in France's Orsay devised a method to design synthetic proteins known as nanobodies which can bind specifically to modified microtubules. These nanobodies are similar to antibodies made in our body as a defence mechanism against pathogens. However, unlike antibodies, the nanobodies are smaller in size and easily amenable to protein engineering.

The nanobody was then coupled with a fluorescent molecule to serve as a detection tool called a sensor. They developed and validated a live cell sensor against a unique microtubule modification called a tyrosinated, a form of microtubules that is already known to be important for cell division and intracellular organisation. The tyrosination sensor is the first tubulin nanobody or sensor that could be used to study the dynamics of microtubule modifications in living cells. These chemicals are frequently used as anti-cancer drugs. Thus, the tyrosination sensor would facilitate studying microtubule functions for many researchers and would aid in identifying new drugs of therapeutic value.