Integrin-associated complexes form hierarchically with variable stoichiometry in nascent adhesions.
Integrin-associated complexes form hierarchically with variable stoichiometry in nascent adhesions.
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DOI：
10.1016/j.cub.2014.07.011
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发表时间：
2014-08-18
期刊：
影响因子：
9.2
通讯作者：
Horwitz, Alan R.
中科院分区：
文献类型：
--
作者：
Bachir, Alexia I.;Zareno, Jessica;Moissoglu, Konstadinos;Plow, Edward F.;Gratton, Enrico;Horwitz, Alan R.
一个复杂的网络的推定分子相互作用的基础上的建筑和功能的细胞基质粘附。这些相互作用中的大多数都涉及使用表达的组分的免疫共沉淀研究，但很少有人在活细胞中被证明或表征功能。我们引入荧光波动的方法来确定，在高的空间和时间分辨率，“何时”和“何地”分子复合物的形式和它们的化学计量在新生的粘连（NAs）。我们专注于整合素相关分子参与整合素激活和整合素-肌动蛋白连接在NAs和显示，这些分子形成整合素含有复合物的层次内的粘附本身。一旦粘连可见，整合素和kindlin就存在于分子复合物中; talin虽然也存在于早期，但仅在NA形成后并响应于肌球蛋白II活性才与整合素-kindlin复合物相关联。此外，talin和黏着斑蛋白协会之前的整合素-talin复合物的形成。最后，α-辅肌动蛋白周期性地进入NAs，并与整联蛋白短暂结合。这些分子的绝对数量和化学计量在所研究的分子之间变化，并且随着粘连成熟而变化。这些观察结果提示了NA组装的工作模型，即瞬时α-辅肌动蛋白-整联蛋白复合物帮助NA在板状伪足内成核。随后，出现了含有kindlin而不是talin的整合素复合物。一旦NA形成，肌球蛋白II活性促进talin与整合素-kindlin复合物以与连接两个整合素-kindlin复合物的每个talin分子一致的化学计量结合。
A complex network of putative molecular interactions underlies the architecture and function of cell-matrix adhesions. Most of these interactions are implicated from co-immunoprecipitation studies using expressed components; but few have been demonstrated or characterized functionally in living cells. We introduce fluorescence fluctuation methods to determine, at high spatial and temporal resolution, ‘when’ and ‘where’ molecular complexes form and their stoichiometry in nascent adhesions (NAs). We focus on integrin-associated molecules implicated in integrin-activation and in the integrin-actin linkage in NAs and show that these molecules form integrin containing complexes hierarchically within the adhesion itself. Integrin and kindlin reside in a molecular complex as soon as adhesions are visible; talin, while also present early, associates with the integrin-kindlin complex only after NAs have formed and in response to myosin II activity. Furthermore, talin and vinculin association precedes the formation of the integrin-talin complex. Finally, α-actinin enters NAs periodically and in clusters that transiently associate with integrins. The absolute number and stoichiometry of these molecules varies among the molecules studied and changes as adhesions mature. These observations suggest a working model for NA assembly, whereby transient α-actinin- integrin complexes help nucleate NAs within the lamellipodium. Subsequently integrin complexes containing kindlin, but not talin, emerge. Once NAs have formed, myosin II activity promotes talin association with the integrin-kindlin complex in a stoichiometry consistent with each talin molecule linking two integrin-kindlin complexes.
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DOI：
10.1083/jcb.200810002
发表时间：
2009-06-29
期刊：
The Journal of cell biology
影响因子：
--
作者：
Kong F;García AJ;Mould AP;Humphries MJ;Zhu C
通讯作者：
Zhu C
影响因子：
6.6
作者：
Carisey, Alex;Ballestrem, Christoph
通讯作者：
Ballestrem, Christoph
影响因子：
4.8
作者：
Chen, Hui;Choudhury, Dilshad M.;Craig, Susan W.
通讯作者：
Craig, Susan W.
影响因子：
3.4
作者：
Choi, Colin K.;Zareno, Jessica;Horwitz, Alan Rick
通讯作者：
Horwitz, Alan Rick
影响因子：
4.8
作者：
Bunch, Thomas A.
通讯作者：
Bunch, Thomas A.