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Self protein-protein interactions are involved in TPPP/p25 mediated microtubule bundling.

DeBonis S, Neumann E, Skoufias DA - Sci Rep (2015)

Bottom Line: However, the C-terminally truncated TPPP/p25 shows a lower Bmax for microtubule binding, suggesting that it may bind to a site of tubulin that is masked in microtubules.Bimolecular fluorescent complementation assays in cells expressing combinations of various TPPP/p25 fragments, but not that of the central folded domain, resulted in the generation of a fluorescence signal colocalized with perinuclear microtubule bundles insensitive to microtubule inhibitors.The data suggest that the central folded domain of TPPP/p25 following binding to microtubules can drive s homotypic protein-protein interactions leading to bundled microtubules.

View Article: PubMed Central - PubMed

Affiliation: Université de Grenoble Alpes, F-38044 Grenoble, France.

ABSTRACT
TPPP/p25 is a microtubule-associated protein, detected in protein inclusions associated with various neurodegenerative diseases. Deletion analysis data show that TPPP/p25 has two microtubule binding sites, both located in intrinsically disordered domains, one at the N-terminal and the other in the C-terminal domain. In copolymerization assays the full-length protein exhibits microtubule stimulation and bundling activity. In contrast, at the same ratio relative to tubulin, truncated forms of TPPP/p25 exhibit either lower or no microtubule stimulation and no bundling activity, suggesting a cooperative phenomenon which is enhanced by the presence of the two binding sites. The binding characteristics of the N- and C-terminally truncated proteins to taxol-stabilized microtubules are similar to the full-length protein. However, the C-terminally truncated TPPP/p25 shows a lower Bmax for microtubule binding, suggesting that it may bind to a site of tubulin that is masked in microtubules. Bimolecular fluorescent complementation assays in cells expressing combinations of various TPPP/p25 fragments, but not that of the central folded domain, resulted in the generation of a fluorescence signal colocalized with perinuclear microtubule bundles insensitive to microtubule inhibitors. The data suggest that the central folded domain of TPPP/p25 following binding to microtubules can drive s homotypic protein-protein interactions leading to bundled microtubules.

No MeSH data available.


Related in: MedlinePlus

Differential stability of the TPPP/p25 induced microtubule bundles in cells.Cells were co-transfected with either FLVN-FLVC (a), ΔNVN-ΔNVC (b), ΔCVN-ΔCVC (c) and then incubated with nocodazole or vinblastine. Only the ΔCVN-ΔCVC microtubule bundles were sensitive to both microtubule inhibitors (scale bars = 17 μm).
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f7: Differential stability of the TPPP/p25 induced microtubule bundles in cells.Cells were co-transfected with either FLVN-FLVC (a), ΔNVN-ΔNVC (b), ΔCVN-ΔCVC (c) and then incubated with nocodazole or vinblastine. Only the ΔCVN-ΔCVC microtubule bundles were sensitive to both microtubule inhibitors (scale bars = 17 μm).

Mentions: The MT bundle stability in the presence of MT depolymerizing drugs was further tested in cells expressing pairs of the different TPPP/p25 fragments. The MT bundles generated by expression of the ΔN-ΔN pair exhibited similar stability as the FLVN-FLVC pair; the generated BiFC signal and the perinuclear MT bundles were insensitive to nocodazole and vinblastine induced depolymerization (Fig. 7). However, the MT bundles generated due to the expression of the ΔCVN-ΔCVC pair were sensitive to depolymerization by both drugs. The data suggest that the ΔC(158) may have lower MT stabilizing properties than the FL and ΔN(49) proteins.


Self protein-protein interactions are involved in TPPP/p25 mediated microtubule bundling.

DeBonis S, Neumann E, Skoufias DA - Sci Rep (2015)

Differential stability of the TPPP/p25 induced microtubule bundles in cells.Cells were co-transfected with either FLVN-FLVC (a), ΔNVN-ΔNVC (b), ΔCVN-ΔCVC (c) and then incubated with nocodazole or vinblastine. Only the ΔCVN-ΔCVC microtubule bundles were sensitive to both microtubule inhibitors (scale bars = 17 μm).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4542545&req=5

f7: Differential stability of the TPPP/p25 induced microtubule bundles in cells.Cells were co-transfected with either FLVN-FLVC (a), ΔNVN-ΔNVC (b), ΔCVN-ΔCVC (c) and then incubated with nocodazole or vinblastine. Only the ΔCVN-ΔCVC microtubule bundles were sensitive to both microtubule inhibitors (scale bars = 17 μm).
Mentions: The MT bundle stability in the presence of MT depolymerizing drugs was further tested in cells expressing pairs of the different TPPP/p25 fragments. The MT bundles generated by expression of the ΔN-ΔN pair exhibited similar stability as the FLVN-FLVC pair; the generated BiFC signal and the perinuclear MT bundles were insensitive to nocodazole and vinblastine induced depolymerization (Fig. 7). However, the MT bundles generated due to the expression of the ΔCVN-ΔCVC pair were sensitive to depolymerization by both drugs. The data suggest that the ΔC(158) may have lower MT stabilizing properties than the FL and ΔN(49) proteins.

Bottom Line: However, the C-terminally truncated TPPP/p25 shows a lower Bmax for microtubule binding, suggesting that it may bind to a site of tubulin that is masked in microtubules.Bimolecular fluorescent complementation assays in cells expressing combinations of various TPPP/p25 fragments, but not that of the central folded domain, resulted in the generation of a fluorescence signal colocalized with perinuclear microtubule bundles insensitive to microtubule inhibitors.The data suggest that the central folded domain of TPPP/p25 following binding to microtubules can drive s homotypic protein-protein interactions leading to bundled microtubules.

View Article: PubMed Central - PubMed

Affiliation: Université de Grenoble Alpes, F-38044 Grenoble, France.

ABSTRACT
TPPP/p25 is a microtubule-associated protein, detected in protein inclusions associated with various neurodegenerative diseases. Deletion analysis data show that TPPP/p25 has two microtubule binding sites, both located in intrinsically disordered domains, one at the N-terminal and the other in the C-terminal domain. In copolymerization assays the full-length protein exhibits microtubule stimulation and bundling activity. In contrast, at the same ratio relative to tubulin, truncated forms of TPPP/p25 exhibit either lower or no microtubule stimulation and no bundling activity, suggesting a cooperative phenomenon which is enhanced by the presence of the two binding sites. The binding characteristics of the N- and C-terminally truncated proteins to taxol-stabilized microtubules are similar to the full-length protein. However, the C-terminally truncated TPPP/p25 shows a lower Bmax for microtubule binding, suggesting that it may bind to a site of tubulin that is masked in microtubules. Bimolecular fluorescent complementation assays in cells expressing combinations of various TPPP/p25 fragments, but not that of the central folded domain, resulted in the generation of a fluorescence signal colocalized with perinuclear microtubule bundles insensitive to microtubule inhibitors. The data suggest that the central folded domain of TPPP/p25 following binding to microtubules can drive s homotypic protein-protein interactions leading to bundled microtubules.

No MeSH data available.


Related in: MedlinePlus