Transition of human gamma-tubulin ring complex into a closed conformation during microtubule nucleation. (https://pubmed.ncbi.nlm.nih.gov/38305685/)

These scientists wanted to understand how cells organize themselves and divide their chromosomes. They focused on a structure called microtubules, which are very important for this process. Microtubules are like tiny tubes that help cells stay organized and make sure the chromosomes are divided correctly.

The scientists were particularly interested in a complex called gamma-tubulin ring complex (gammaTuRC), which helps in making microtubules. They noticed that when gammaTuRC is by itself, it looks different from the microtubule structure. This made them wonder how gammaTuRC actually helps in making microtubules.

To find out, the scientists used a special technique called cryo-electron microscopy to look at the structure of gammaTuRC when it is attached to a newly forming microtubule. They found that when gammaTuRC is connected to the microtubule, it undergoes some changes and becomes a closed structure. This closed structure is important because it helps gammaTuRC to create the correct kind of microtubule that is found in human cells.

The scientists also discovered that a part of gammaTuRC, called the latch, interacts with the building blocks of microtubules to help in closing the structure. This latch is like a lock that keeps everything in place.

In addition to the latch, all the parts of gammaTuRC and a bridge made of actin undergo rearrangements to complete the closing process. This closing mechanism is very important for microtubule formation.

Based on their findings, the scientists proposed a mechanism for how gammaTuRC helps in making microtubules in human cells. They believe that the large-scale changes in the structure of gammaTuRC are regulated by cells to ensure that microtubules are formed correctly.

Overall, this study helped the scientists understand how cells use gammaTuRC to make microtubules, which is important for cell organization and chromosome division.

Brito C., Serna M., Guerra P., Llorca O., Surrey T. Transition of human gamma-tubulin ring complex into a closed conformation during microtubule nucleation. Science. 2024 Feb 2:eadk6160. doi: 10.1126/science.adk6160.