Identification of a novel small Arabidopsis protein interacting with gamma-tubulin complex protein 3.

In higher plants, microtubules (MTs) show dynamic structural changes during cell cycle and development progression. A precise control of MT nucleation at dispersed sites is one way used to regulate the cytoskeletal organization. Some gamma-tubulin complex proteins (GCPs) were previously identified in Arabidopsis thaliana (At). They are directly involved in the nucleation process. Nevertheless, no additional player which may anchor the nucleating complex or regulate the nucleation activity has been found in plant cells so far. Therefore, our aim was the identification of Arabidopsis proteins interacting with MT nucleating complexes and particularly with AtGCP3. Performing a yeast two-hybrid screen, we discovered a new protein which we called AtGCP3 Interacting Protein 1 (AtGIP1). The possible role of this protein during the nucleation process is discussed.