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Detection of Heterodimerization of Protein Isoforms Using an in Situ Proximity Ligation Assay
Published on: October 20, 2018
Molecular insights into mammalian end-binding protein heterodimerization
Christian O De Groot1, Ilian Jelesarov, Fred F Damberger
1Biomolecular Research, Structural Biology, the Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland.
The Journal of Biological Chemistry
|December 17, 2009
Summary
Human EB1 and EB3 proteins form heterodimers, while EB2 does not significantly participate in heterotypic complexes. This dimerization influences microtubule dynamics and protein interactions within cells.
Area of Science:
- Cell Biology
- Molecular Biology
- Biochemistry
Background:
- Microtubule plus-end tracking proteins (+TIPs) regulate microtubule dynamics and recruit other +TIPs.
- End-binding (EB) proteins are a conserved family of +TIPs crucial for microtubule function.
Purpose of the Study:
- Investigate the dimerization properties of human EB1, EB2, and EB3 proteins.
- Elucidate the molecular mechanisms governing homo- and heterodimer formation.
- Determine the role of binding partners in controlling EB dimerization.
Main Methods:
- Förster resonance energy transfer (FRET) to study protein chain exchange.
- Fluorescence spectroscopy and nuclear magnetic resonance (NMR) to analyze binding interactions.
- Homology modeling and mutagenesis to identify key molecular determinants.
- Live cell imaging to observe dimerization in cellular contexts.
Main Results:
- C-terminal domains of EB proteins (EBc) readily exchange chains in solution.
- EB1c and EB3c preferentially form heterodimers; EB2c shows limited heterotypic complex formation.
- Binding partners like CLIP-170, p150(glued), and APC modulate EBc chain exchange.
- Heterodimer formation between full-length EB1 and EB3 occurs in vitro and in cells, unlike EB2.
Conclusions:
- Provides molecular insights into the dimerization preferences of EB proteins.
- Explains the dominant negative control exerted by C-terminal EB domains.
- Forms a basis for understanding the functional significance of heterotypic EB chain exchange in cellular processes.
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