plus-end-directed vesicle transport along microtubule

Definition

Target type: biologicalprocess

The directed movement of a vesicle towards the plus end of a microtubule, mediated by motor proteins. This process begins with the attachment of a vesicle to a microtubule, and ends when the vesicle reaches its final destination. [GOC:BHF, GOC:mah]

Plus-end-directed vesicle transport along microtubules is a fundamental process in eukaryotic cells, responsible for the efficient and directed movement of cargo-laden vesicles throughout the cytoplasm. Microtubules, dynamic filamentous structures composed of α- and β-tubulin dimers, provide tracks for this transport. The process involves a complex interplay of motor proteins, adaptor proteins, and regulatory mechanisms, ensuring accurate delivery of vesicles to their designated destinations.

**Motor Proteins:** The driving force behind plus-end-directed vesicle transport is provided by kinesin motor proteins. Kinesins are a diverse family of ATPases that bind to microtubules and use the energy derived from ATP hydrolysis to move along the microtubule track. They bind to vesicles via adaptor proteins, linking the vesicle to the microtubule. Kinesins typically move towards the plus end of microtubules, which is the end where microtubule polymerization occurs and is often located at the periphery of the cell.

**Adaptor Proteins:** Adaptor proteins play a crucial role in mediating the interaction between kinesin motors and cargo vesicles. They can bind to specific receptors on the vesicle surface, facilitating the recruitment of kinesin motors. Adaptor proteins also contribute to the specificity of vesicle transport, ensuring that the appropriate cargo is delivered to the correct location.

**Regulation of Plus-End-Directed Transport:** The directionality and efficiency of plus-end-directed vesicle transport are tightly regulated. Various signaling pathways and cellular cues can modulate the activity of kinesin motors, influencing their binding to microtubules and the speed of their movement. For example, phosphorylation of kinesin can activate or inhibit its motor activity. Furthermore, microtubule dynamics, including polymerization and depolymerization, can influence the direction and distance of vesicle movement.

**Biological Significance:** Plus-end-directed vesicle transport is essential for a wide range of cellular processes, including:

* **Secretion:** Transport of secretory vesicles from the Golgi apparatus to the plasma membrane for exocytosis.
* **Endocytosis:** Transport of endocytosed vesicles from the plasma membrane to endosomes and lysosomes.
* **Organelle Transport:** Movement of organelles, such as mitochondria and lysosomes, to specific cellular locations.
* **Synaptic Transmission:** Transport of neurotransmitter-filled vesicles to the presynaptic terminal for neurotransmitter release.

**Conclusion:** Plus-end-directed vesicle transport along microtubules is a highly organized and dynamic process that is crucial for maintaining cellular function and integrity. The intricate interplay of motor proteins, adaptor proteins, and regulatory mechanisms ensures the efficient delivery of cargo vesicles to their designated targets, facilitating essential cellular processes and maintaining overall cellular homeostasis.'
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Proteins (1)

Compounds (5)