Reconstitution of the dynamic microtubule and kinetochore interface

During mitosis, genetic integrity of eukaryotic cells is critically dependent on the capture and stable attachment of microtubules (MTs) to the kinetochores. Kinetochores and MTs can be both regarded as nanodevices that interact and are able to create a machine capable of moving bulky objects such as chromosomes during cell division. Many of the MTs activities are mediated by interaction with a large number of microtubule associated proteins (MAPs), but knowledge is still fragmentary about how these proteins are involved and how the process is spatially and temporarily regulated within the cells. Poisons that affect MT function have been identified. Some, but not all, of these compounds, have clinical utility as anti-cancer drugs. Understanding the molecular mechanisms subtending to the function of microtubules and associated proteins is important to identify and characterize new molecular targets in anti-cancer therapy. The MT plus end is the contact surface between MTs and kinetochores, and to date, several associating proteins called +TIPs were identified as being specifically binding the microtubule plus end. We will investigate the interactions of +TIPs such as CLIP170 and EB1 with the Ndc80 complex, a constituent of the outer kinetochore that has recently emerged as a direct point of contact between kinetochores and microtubules. The aim of the project will be to reconstitute in vitro, in part or entirely, a human MT-kinetochore complex interface and try to unveil the molecular mechanisms involved in the interactions between MTs and kinetochores.