Insights on the Interaction of MBP with Microtubules

GALIANO MR, LOPEZ-SAMBROOKS C AND HALLAK ME

Intrinsically Disordered Proteins

Publisher Nova Science Publisher, Inc

Lugar: Montreal Canada Editor JM Boggs; Año: 2008; p. 127 - 147

One of the cellular elements of the glia in the central nervous system (CNS) is the oligodendrocyte. Lamella from these specialized cells, which warps the neuronal axons, provides and maintains the myelin sheath that serves to speed up the action potentials by saltatory conduction. In oligodendrocytes there are a large class of proteins predominantly cytoplasmic called Myelin Basic Proteins (MBP) that have a central role in the myelin formation. During myelinogenesis, these cells extend branched processes toward axons and the extension of these processes as well as the formation of the myelin sheaths are supported by the oligodendrocyte cytoskeleton assembled by microtubules and microfilaments (1). Several studies have recognized the relevance of cytoskeletal arrangement during the morphological differentiation of oligodendrocytes (2-5) as well as the reorganization of microtubules and microfilaments during the formation of processes and branches (6). The present review will emphasize the interaction between MBP and the microtubules. Moreover among the putative functions derived from this interaction, and also between MBP and microfilaments an active participation of MBP in oligodendroglial differentiation has been suggested. Thus, beside the known role of MBP in myelin compaction, another function of MBP is in the ordering of the oligodendrocytes cytoskeletal elements during the CNS axonal myelination. In general the cytoskeleton participates in several functions of eukaryotic cells. It is responsible of maintenance of cell morphology, intracellular vesicular transport and cell surface receptor modulation. It is also vital for the processes of cell motility, differentiation and mitosis (7). The microtubules are actively implicated in these functions. The dynamic characteristics of the microtubules are not only depending of intrinsic dynamic properties but also on the microtubule interactions with several cytoplasmic proteins. The putative role of MBP as a microtubule-interacting protein concerned in the coordination of cytoskeleton changes during oligodendrocyte differentiation and how its post-translational modifications are involved in these interactions will be the focus of discussion in this chapter.