organelle transport along microtubule

Definition

Target type: biologicalprocess

The directed movement of an organelle along a microtubule, mediated by motor proteins. This process begins with the attachment of an organelle to a microtubule, and ends when the organelle reaches its final destination. [GOC:mah]

Organelle transport along microtubules is a fundamental cellular process that enables the efficient movement of organelles throughout the cytoplasm. Microtubules, long cylindrical structures composed of the protein tubulin, serve as tracks for motor proteins, which bind to and move along these tracks. These motor proteins, belonging to the kinesin and dynein families, act as molecular machines that convert chemical energy from ATP hydrolysis into mechanical work, propelling organelles along the microtubules.

Kinesins typically move towards the plus end of microtubules, which is often located at the cell periphery, while dyneins move towards the minus end, which is typically located near the nucleus. The directionality of these motor proteins is determined by their specific binding sites on microtubules and their interactions with other cellular components.

The process of organelle transport can be broadly divided into three main stages:

1. **Cargo Recognition and Binding:** Motor proteins recognize and bind to specific cargo molecules on organelles. These cargo molecules can be proteins, lipids, or other molecules that mark the organelle for transport. The binding of the motor protein to its cargo is highly specific and is mediated by interactions between the motor protein's cargo-binding domain and the cargo molecule.

2. **Microtubule Association and Movement:** Once bound to its cargo, the motor protein associates with the microtubule. The motor protein binds to the microtubule using its microtubule-binding domain, which interacts with specific tubulin subunits within the microtubule. The binding of the motor protein to the microtubule allows it to move along the track, propelled by the hydrolysis of ATP.

3. **Cargo Delivery and Release:** As the motor protein moves along the microtubule, it carries its cargo towards its designated destination. Upon reaching its target, the motor protein releases its cargo through a process that is not fully understood. This release event may be triggered by specific signaling pathways or by interactions with other proteins at the target site.

Organelle transport along microtubules is essential for various cellular functions, including:

- **Intracellular trafficking:** Delivery of proteins, lipids, and other molecules to their appropriate destinations within the cell.
- **Cell division:** Transport of chromosomes and other cellular components during mitosis and meiosis.
- **Signal transduction:** Movement of signaling molecules and receptors within the cell, allowing for efficient communication between different parts of the cell.
- **Cell polarity:** Establishment and maintenance of distinct cellular domains, such as the apical and basal regions of epithelial cells.

Disruptions in organelle transport can lead to various cellular malfunctions and diseases, highlighting the crucial role of this process in maintaining cellular homeostasis.'
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Proteins (2)

Compounds (67)