Conventional kinesin is a ubiquitous organelle transporter that moves cargo toward the plus-ends of microtubules. In addition, several in vitro studies indicated a role of conventional kinesin in cross-bridging and sliding microtubules, but in vivo evidence for such a role is missing. In this study, we show that conventional kinesin mediates microtubule-microtubule interactions in the model fun...

The structure, dynamic behavior, and spatial organization of microtubules are regulated by microtubule-associated proteins. An important microtubule-associated protein is the protein Tau, because its microtubule interaction is impaired in the course of Alzheimer's disease and several other neurodegenerative diseases. Here, we show that Tau binds to microtubules by using small groups of evolutio...

Microtubules are filamentous polymers essential for cell viability. Microtubule plus-end tracking proteins (+TIPs) associate with growing microtubule plus ends and control microtubule dynamics and interactions with different cellular structures during cell division, migration, and morphogenesis. EB1 and its homologs are highly conserved proteins that play an important role in the targeting of +...

The microtubule content of the isolated mitotic apparatus of sea-urchin eggs (Arbacia punctulata) has been investigated by electron microscopy. Cross-sections were made through asters or spindles of flat-embedded mitotic apparatuses of known mitotic stage and specific orientation in the block. Cross-sections between chromosomes and poles of five metaphase half-spindles revealed approximately 20...

Coupling of motor proteins within large arrays drives muscle contraction, flagellar beating, chromosome segregation, and other biological processes. Short-range interaction mechanisms coupling, such as steric crowding mechanical linkage, have been well-studied. However, coupling that act at longer length scales remain largely unexplored. Here we report evidence long-range motor-motor on microtu...

BACKGROUND Microtubule ends have distinct biochemical and structural features from those of the lattice. Several proteins that control microtubule behavior can distinguish the end of a microtubule from the lattice. The end-binding protein EB1, for example, recognizes the nucleotide state of microtubule ends, which are enriched in GTP-tubulin. EB1 shares its binding site with Doublecortin (DCX),...

Tau is one of several types of microtubule-associated proteins (MAPs), responsible for the assembly and stability of microtubule networks that is present only in neurons and predominantly localized in axons which its functions are tightly regulated by phosphorylation. Via as yet unknown mechanisms, tau becomes hyperphosphorylated and accompanies with neuronal degeneration, loss of synapses...

Microtubule dynamics are critically important for plant cell development. Here, we show that Arabidopsis thaliana ARMADILLOREPEAT KINESIN1 (ARK1) plays a key role in root hair tip growth by promoting microtubule catastrophe events. This destabilizing activity appears to maintain adequate free tubulin concentrations in order to permit rapid microtubule growth, which in turn is correlated with un...

Point and regional centromeres specify a unique site on each chromosome for kinetochore assembly. The point centromere in budding yeast is a unique 150-bp DNA sequence, which supports a kinetochore with only one microtubule attachment. In contrast, regional centromeres are complex in architecture, can be up to 5 Mb in length, and typically support many kinetochore-microtubule attachments. We us...

In previous work we have demonstrated that the microtubule-associated protein 2 (MAP 2) molecule consists of two structural parts. One part of the molecule, referred to as the assembly-promoting domain, binds to the microtubule surface and is responsible for promoting microtubule assembly; the other represents a filamentous projection observed on the microtubule surface that may be involved in ...