Abstract
Microtubule(MT) structure is highly conserved in eukaryotes. Stable heterodimers of α-tubulin and β-tubulin are stacked longitudinally to form a tubulin protofilaments and 13 protofilaments are associated laterally to form a hollow MT. Previously, we showed that dominant negative left-handed helical growth mutants lefty1 and lefty2 have a missense mutation in two α-tubulins at the α-β interacting region of intradimer surface and form unstable MTs.
Here, we screened a large collection of mutants that are hypersensitive to MT destabilizing drugs and investigated relationships between tubulin mutations and twisting phenotypes. Three left-handed mutants had mutations at intradimer regions, 3 left-handed mutants and 4 right-handed mutants carried mutation at interdimer regions, 10 right-handed mutants and 1 left-handed mutant were tubulin mutated at lateral regions, and two right-handed mutants were found to be mutated at GTPase activating regions of α-tubulin. Cortical microtubule arrays and dynamics in the mutants are being analyzed.
