Quantitative analysis of MAP-mediated regulation of microtubule dynamic instability in vitro focus on Tau

The regulation of microtubule growing and shortening dynamics is essential for proper cell function and viability, and microtubule-associated proteins (MAPs) such as the neural protein tau are critical regulators of these dynamic processes. Further, we and our colleagues have proposed that misregulation of microtubule dynamics may contribute to tau-mediated neuronal cell death and dementia in Alzheimer's and related diseases. In the first part of this chapter, we present a general background on microtubule dynamics and then focus in on tau. We review the literature on the roles of tau in normal neuronal cell biology, the tau structure-function relationship, regulatory mechanisms influencing tau action, and pathological tau action, including normal and aberrant regulation of microtubule dynamics. In the second part of this chapter, we present detailed protocols for various in vitro procedures often used in studying tau-mediated regulation of microtubule dynamics, including purification and characterization of necessary reagents, microtubule assembly assays, and microtubule dynamics assays. Importantly, these assays are readily adaptable to examine other regulators of microtubule dynamics besides tau. In the final analysis, in vitro analyses of MAP-mediated regulation of microtubule dynamics will provide extremely valuable insights into our understanding of normal and pathological cell biology.