Description: Plant microtubules play essential roles in cell processes such as cell division, cell elongation, and organelle organization. Microtubules are arranged in highly dynamic and ordered arrays, but unlike animal cells, plant cells lack centrosomes. Therefore, microtubule nucleation and organization are governed by microtubule-associated proteins, including a microtubule-severing protein, katanin. Mutant analysis and in vitro characterization has shown that the highly conserved katanin is needed for the organization of the microtubule arrays in Arabidopsis and rice as well as in a variety of animal models. Katanin is a protein complex that is part of the AAA+ family of ATPases. Katanin is composed of two subunits, katanin-p60, a catalytic subunit and katanin-p80, a regulatory subunit. Spastin is another MT-severing protein that was identified on the basis of its homology to katanin. In animal cells, spastin is also needed for microtubule organization, but its functionality has not yet been investigated in plants. To initiate an exploration of the function of katanin-p60 and spastin in Zea mays, my research goal was to generate tools for the expression and purification of maize katanin-p60 and spastin proteins in vitro. Plasmids that express katanin-p60 and spastin with N-terminal GST tags were designed and constructed via In-Fusion® cloning after traditional cloning methods were not successful. The constructs were expressed in E. coli, then the recombinant proteins were purified. To determine if the GST-tagged proteins are functional, ATPase activity and tubulin polymerization assays were performed. While both GST-katanin-p60 and GST-spastin hydrolyzed ATP indicating that the ATPase domains are functional, the results of the tubulin polymerization assays were less clear and further experimentation is necessary.
Date: December 2017
Creator: Alodailah, Sattam Sonitan
Partner: UNT Libraries