They have 13 protofilaments around a hollow center, and form spindle fibers in cell division.
By releasing SAFs, a RanGTP gradient promotes formation of these structures, whose stability is improved by removing their C-terminal tyrosine. Katanin severs these structures, which are stabilized by Tau proteins. These structures go through rescue and catastrophe phases in (*) dynamic instability. Kinesins move toward their plus end, and eukaryotic cilia have a 9+2 assembly of them. They have 13 protofilaments around a hollow center, and form spindle fibers in cell division. For 10 points, name these cytoskeletal components made of long tubulin polymers.
By releasing SAFs, a RanGTP gradient promotes formation of these structures, whose stability is improved by removing their C-terminal tyrosine.
microtubules [prompt on "spindle fibers" until mentioned]