کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
2043550 | 1073364 | 2008 | 5 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Microtubule-Driven Multimerization Recruits ase1p onto Overlapping Microtubules Microtubule-Driven Multimerization Recruits ase1p onto Overlapping Microtubules](/preview/png/2043550.png)
SummaryMicrotubule (MT) crosslinking proteins of the ase1p/PRC1/Map65 family play a major role in the construction of MT networks such as the mitotic spindle. Most homologs in this family have been shown to localize with a remarkable specificity to sets of MTs that overlap with an antiparallel relative orientation 1, 2, 3 and 4. Regulatory proteins bind to ase1p/PRC1/Map65 and appear to use the localization to set up precise spatial signals 5, 6, 7, 8, 9 and 10. Here, we present evidence for a mechanism of localized protein multimerization underlying the specific targeting of ase1p, the fision yeast homolog. In controlled in vitro experiments, dimers of ase1-GFP diffused along the surface of single MTs and, at concentrations above a certain threshold, assembled into static multimeric structures. We observed that this threshold was significantly lower on overlapping MTs. We also observed diffusion and multimerization of ase1-GFP on MTs inside living cells, suggesting that a multimerization-driven localization mechanism is relevant in vivo. The domains responsible for MT binding and multimerization were identified via a series of ase1p truncations. Our findings show that cells use a finely tuned cooperative localization mechanism that exploits differences in the geometry and concentration of ase1p binding sites along single and overlapping MTs.
Journal: - Volume 18, Issue 21, 11 November 2008, Pages 1713–1717