Microtubule-binding proteins

Tau is a microtubule-binding protein that is believed to be important for the assembly and stabilization of microtubules [ 19]. In nerve cells, tau is normally found in axons,... 

Walenta, J. H., Didier, A. J., Liu, X., and Kramer, H. (2001). The Golgi-associated hook3 protein is a member of a novel family of microtubule-binding proteins. J. Cell Biol. 152, 923-934. 

Neuropathology of Alzheimer s is also defined by accumulation of another form of insoluble protein, the neurofibrillary tangles (NFTs). NFTs are fibrillar structures largely composed of tau, a microtubule-binding protein that stabilises the microtubule tracts necessary for vesicular trafficking, endo- and exocytosis and axonal polarity. No tau mutations have yet been identified... 

I analyzed the movement of a microtubule binding protein ebl labeled with green fluorescent protein in Vero cell, ebl is thought to be involved in controUing the stability of microtubule. The sequence was taken using a spinning disk con-focal microscope (UltraVIEW, Perkin-Elmer, UK) at two frames per minute. 

The cytoskeleton also contains different accessory proteins, which, in accordance with their affinities and functions, are designated as microtubule-associated proteins (MAPs), actin-binding proteins (ABPs), intermediate-filament-associated proteins (IFAPs), and myosin-binding proteins. This chapter is focused on those parts of the cytoskeleton that are composed of microfilaments and microtubules and their associated proteins. The subject of intermediate filaments is dealt with in detail in Volume 2. 

Microtubule-associated proteins bind to microtubules in vivo and subserve a number of functions including the promotion of microtubule assembly and bundling, chemomechanical force generation, and the attachment of microtubules to transport vesicles and organelles (Olmsted, 1986). Tubulin purified from brain tissue by repeated polymerization-depolymerization contains up to 20% MAPs. The latter can be dissociated from tubulin by ion-exchange chromatography. The MAPs from brain can be resolved by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). 

The microtubule-associated proteins MAP2 and tau both have two separate functional regions (Lewis et al., 1989). One is the microtubule-binding site, which nucleates microtubule assembly and controls the rate of elongation (by slowing the rate of assembly). The second functional domain shared by MAP2 and tau is a short C-terminal a-helical sequence that can cross-link microtubules into bundles by self-interaction. This domain has some of the properties of a leucine zipper. Likely it is responsible for the organization of microtubules into dense stable parallel arrays in axons and dendrites (Lewis et al., 1989). 

The Role of Myosins in Cell Locomotion The Role of Actin-Binding Proteins in Cell Locomotion The Transduction of Extracellular Motility Signals to the Cytoskeleton Lipid Flow and Cell Locomotion The Role of Cell Locomotion in Metastasis Intracellular Motility Microtubule-Based Intracellular Motility... 

Microtubule-associated proteins Actin-binding proteins... 

Paclitaxel is an alkaloid ester derived from the Pacific yew (Taxus brevifolia) and the European yew (Taxus baccata). The drug functions as a mitotic spindle poison through high-affinity binding to microtubules with enhancement of tubulin polymerization. This promotion of microtubule assembly by paclitaxel occurs in the absence of microtubule-associated proteins and guanosine triphosphate and results in inhibition of mitosis and cell division. 

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