plusenddirected

Plus-end-directed refers to movement along microtubules toward the plus end, the end typically oriented toward the cell periphery. In eukaryotic cells microtubules are polar, with a minus end anchored near the microtubule organizing center and a plus end extending outward. Plus-end-directed transport is mediated primarily by kinesin motor proteins, which use ATP hydrolysis to take forward steps toward the microtubule plus end. Kinesin-1 (conventional kinesin) is the canonical motor for organelle and vesicle transport toward the cell periphery, with other family members such as kinesin-2 and kinesin-3 contributing to specific cargoes. Some kinesins are involved in mitotic spindle dynamics, sliding microtubules to separate poles or position chromosomes.

In contrast, dynein moves toward the minus end, powering retrograde transport toward the microtubule organizing center. Many cargoes are transported by a balance of plus- and minus-end-directed motors, leading to bidirectional movement dependent on motor coordination and regulatory factors.

Regulation of plus-end-directed transport involves cargo adapters that recruit kinesins to cargo, post-translational modifications of motors, and microtubule-associated proteins that modulate track accessibility, including plus-end tracking proteins that influence motor binding at growing microtubule ends.

Physiological roles include axonal transport of synaptic vesicles and mitochondria in neurons, delivery of Golgi-derived vesicles to the periphery, endosome and lysosome positioning, and participation in spindle assembly during cell division.