microtubule plus-end binding

Definition

Target type: molecularfunction

Binding to the plus end of a microtubule. [GOC:ai, PMID:14557818, PMID:14614826]

Microtubule plus-end binding proteins (also known as +TIPs) play a crucial role in regulating microtubule dynamics and function. They specifically bind to the growing, dynamic ends of microtubules, the plus ends, and participate in a diverse array of cellular processes. Here is a detailed description of their molecular function:

1. **Microtubule Stabilization:** +TIPs often act as microtubule stabilizers, preventing premature depolymerization and promoting microtubule elongation. They achieve this by interacting with the tubulin subunits at the plus end, effectively shielding them from depolymerizing factors.

2. **Microtubule Polymerization Control:** +TIPs can directly influence the rate of microtubule polymerization. Some +TIPs promote polymerization by enhancing the addition of tubulin dimers to the growing end, while others act as inhibitors, slowing down or pausing the polymerization process.

3. **Microtubule Guiding and Directionality:** +TIPs contribute to the precise spatial organization of microtubules within the cell. They can guide microtubules towards specific cellular destinations or direct their growth along particular pathways. This is often achieved by linking microtubules to other cellular components, such as motor proteins or signaling pathways.

4. **Microtubule Bundling and Cross-linking:** Some +TIPs participate in the formation of microtubule bundles, either by directly cross-linking microtubules or by recruiting other proteins involved in bundling. This allows for the creation of stable microtubule structures, such as the mitotic spindle.

5. **Signal Transduction and Integration:** +TIPs often act as signaling hubs, integrating various cellular signals and relaying them to the microtubule cytoskeleton. They can bind to other proteins involved in signaling pathways, such as kinases, phosphatases, and adaptor proteins, and modulate their activity.

6. **Cellular Processes:** The diverse functions of +TIPs contribute to a wide range of cellular processes, including:
- **Cell migration:** +TIPs are involved in the dynamic reorganization of the microtubule network during cell migration, guiding the leading edge and facilitating movement.
- **Cell division:** +TIPs play a crucial role in mitosis, regulating the formation and stability of the mitotic spindle, ensuring accurate chromosome segregation.
- **Vesicle transport:** +TIPs can link microtubules to motor proteins, facilitating the transport of vesicles and organelles along microtubule tracks.
- **Organelle positioning:** +TIPs contribute to the precise localization and organization of organelles within the cell, ensuring proper cellular function.

In summary, +TIPs are a diverse group of proteins that bind to the dynamic plus ends of microtubules. They exhibit a range of molecular functions, including stabilization, polymerization control, guiding, bundling, signal transduction, and participation in crucial cellular processes. Their dynamic interactions with microtubules are essential for the proper organization and function of the cytoskeleton and contribute to a wide array of cellular activities.'
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Proteins (3)

Compounds (8)