Subpellicular Microtubules in Apicomplexa and Trypanosomatids

The cytoskeleton plays a fundamental role in various processes such as the establishment of cell shape, cell locomotion, and the intracellular motility of various structures found in eukaryotic cells. Microtubules are among the most conspicuous structures in the cytoskeleton. They can be found free in the cytoplasm, forming the mitotic spindle or assembled in various structures. A special type of microtubule arrangement is found in some protozoa, whereby they are organized as a single layer located immediately below the plasma membrane, constituting what is generally referred to as subpellicular microtubules. This special array of microtubules is found in members of the Kinetoplastida family and in the Apicomplexa phylum. Here, we review basic aspects of subpellicular microtubules, emphasizing their visualization as a whole network, their structural organization, their heterogeneity as analyzed using an immunocytochemical approach, some of their biochemical properties, and their sensitivity to drugs, as well as their functional role.