Microtubules and Associated Proteins in Oligodendrocytes, the Myelin Forming Cells of the Central Nervous System

During the process of myelination, oligodendrocytes spirally enwrap neuronal axons and form multilamellar myelin sheets. Oligodendrocytes in culture are characterized by their numerous membranous extensions containing an elaborate network of microtubules, they are devoid of intermediate filaments, but microfilaments are prominent. To support cell morphology and for the establishment and maintenance of the myelin membrane, an intact, spatially organized cytoskeleton with dynamic properties is essential. A variety of microtubule-associated proteins (MAPs), including MAP2, MAP1B, and tau, regulating growth and stability of microtubules, are present in oligodendrocytes, and also the myelin-specific proteins MBP and CNP associate with microtubules. Furthermore, heat shock proteins interact with the cytoskeleton and in response to cellular stress may be recruited to the cytoskeleton. Glial dysfunction and glial pathology accompany a number of neurodegenerative diseases. During disease progression, proteins with stabilizing or destabilizing properties are recruited to the cytoskeleton and alter microtubule properties. A characteristic hallmark of many diseases is abnormal deposits of cytoskeletal proteins and the accumulation of cellular proteins, such as tau and/or α-synuclein. The identification of microtubule-associated proteins during health and disease will provide insights into our overall understanding of the regulation and mechanistic aspects of microtubule organization and functions. The method described in this chapter provides a rapid and simple way to identify proteins which bind to or are detached from microtubules under normal or pathological situations in living cells.