It’s no secret, but I’ll say it anyway…I love microtubules. Really, several qualities of microtubules are ones we all inspire to have ourselves…dynamic, elegant, organized, photogenic, and essential. The image above is from a recent paper discussing how different tubulin isotypes may play bigger roles in microtubule behavior than once believed.
Microtubules are hollow tubes of linear protofilaments that are composed of α- and β-tubulin heterodimers. Most organisms have multiple isotypes of α- and β-tubulin, some of which are expressed in the same cells. It was not clear if some of these isotypes could be used interchangeably in the assembly and function of microtubules, but a recent paper describes how one specific β-tubulin isotype affects microtubule behavior. The altered dynamics of microtubules when this isotype, called β5-tubulin, is either overexpressed or reduced results in cell division defects. In seen in the images above, mammalian cells with too much β5-tubulin (left) had many short microtubules (arrowheads) and indicators of cell division defects (compare fragmented nucleus to neighboring cell’s nucleus). Cells with reduced levels of β5-tubulin (right) had normal looking microtubules despite defects in cell division.
Bhattacharya, R., Yang, H., & Cabral, F. (2011). Class V -tubulin alters dynamic instability and stimulates microtubule detachment from centrosomes Molecular Biology of the Cell, 22 (7), 1025-1034 DOI: 10.1091/mbc.E10-10-0822