Cell and molecular biology of microtubule plus end tracking proteins: end binding proteins and their partners.

The microtubule plus end is a crucial site for the regulation of microtubule dynamics and microtubule association with different cellular organelles and macromolecular complexes. Several evolutionarily conserved groups of proteins form comet-like accumulations at the growing microtubule plus ends. These proteins belong to functionally diverse and structurally unrelated families: they include motors, nonmotor proteins, microtubule polymerases, and depolymerases as well as regulatory and adaptor proteins. Here, we provide an overview of microtubule plus end binding proteins, describe what is known about the mechanisms of their association with growing microtubule tips, and discuss their functional properties in relation to microtubule plus end accumulation.