Page last updated: 2024-10-24

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)

ProteinDefinitionTaxonomy
Tau-tubulin kinase 2A tau-tubulin kinase 2 that is encoded in the genome of human. [PRO:DNx, UniProtKB:Q6IQ55]Homo sapiens (human)
Stromal interaction molecule 1A stromal interaction molecule 1 that is encoded in the genome of human. [PRO:DNx, UniProtKB:Q13586]Homo sapiens (human)
Adenomatous polyposis coli proteinAn adenomatous polyposis coli protein that is encoded in the genome of human. [PMID:11283619, PMID:20823832, PRO:KER]Homo sapiens (human)

Compounds (8)

CompoundDefinitionClassesRoles
sb 2021904-(4-fluorophenyl)-2-(4-hydroxyphenyl)-5-(4-pyridyl)imidazole: structure given in first source; inhibits p38 MAP kinaseimidazoles;
organofluorine compound;
phenols;
pyridines
apoptosis inducer;
EC 2.7.11.24 (mitogen-activated protein kinase) inhibitor
toxoflavintoxoflavin : A pyrimidotriazine that is 1,6-dimethyl-1,5,6,7-tetrahydropyrimido[5,4-e][1,2,4]triazine with oxo groups at positions 5 and 7.

toxoflavin: azapteridine antibiotic; structure
carbonyl compound;
pyrimidotriazine
antibacterial agent;
antineoplastic agent;
apoptosis inducer;
bacterial metabolite;
toxin;
virulence factor;
Wnt signalling inhibitor
cercosporincercosporin : An organic heterohexacyclic compound that is perylo[1,12-def][1,3]dioxepine-6,11-dione substituted by hydroxy groups at positions 5 and 12, by methoxy groups at positions 7 and 10, and by 2-hydroxypropyl groups at positions 8 and 9 (the R,R-stereoisomer). It is a phytotoxin which was first isolated from the pathogenic soybean fungus, Cercospora kikuchii and later found in multiple members of the genus Cercospora.

cercosporin: phyytotoxin from Cercospora beticola Sacc; posses photodynamic action on mice, bacteria & plants
ucn 1028 ccalphostin C: structure given in first source; isolated from Cladosporium cladosporioides
gsk-5498a2,6-difluoro-N-(1-(2-fluoro-6-(trifluoromethyl)benzyl)-1H-pyrazol-3-yl)benzamide: structure in first source

GSK-5498A : A member of the class of pyrazoles that is 1H-pyrazole substituted by 2-fluoro-6-(trifluoromethyl)benzyl and (2,6-difluorobenzoyl)amino groups at positions 1 and 3, respectively. It is a inhibitor of Ca(2+) release-activated Ca(2+) (CRAC) channel and inhibits the release of mast cell mediators and T-cell cytokines in human and rat preparations.
(trifluoromethyl)benzenes;
difluorobenzene;
pyrazoles;
secondary carboxamide
calcium channel blocker
teriflunomide(trifluoromethyl)benzenes;
aromatic amide;
enamide;
enol;
nitrile;
secondary carboxamide
drug metabolite;
EC 1.3.98.1 [dihydroorotate oxidase (fumarate)] inhibitor;
hepatotoxic agent;
non-steroidal anti-inflammatory drug;
tyrosine kinase inhibitor
ethyl 1-(4-(2,3,3-trichloroacrylamido)phenyl)-5-(trifluoromethyl)-1h-pyrazole-4-carboxylateethyl 1-(4-(2,3,3-trichloroacrylamido)phenyl)-5-(trifluoromethyl)-1H-pyrazole-4-carboxylate: structure in first source
gsk-7975a2,6-difluoro-N-(1-(4-hydroxy-2-(trifluoromethyl)benzyl)-1H-pyrazol-3-yl)benzamide: structure in first source