Biochemical characterization of actin assembly mechanisms with ALS-associated profilin variants.
Biochemical characterization of actin assembly mechanisms with ALS-associated profilin variants.
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DOI：
10.1016/j.ejcb.2022.151212
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发表时间：
2022-04
影响因子：
6.6
通讯作者：
Henty-Ridilla, Jessica L.
中科院分区：
文献类型：
--
作者：
Liu, Xinbei;Pimm, Morgan L.;Haarer, Brian;Brawner, Andrew T.;Henty-Ridilla, Jessica L.
肌动蛋白结合蛋白profilin-1中的八个独立突变已被确定为肌萎缩侧索硬化症（ALS）的罕见原因。Profilin通过调节脂质、核信号和细胞骨架动力学（包括肌动蛋白丝组装）对许多神经元细胞过程是必需的。profilin和肌动蛋白单体之间的直接相互作用抑制肌动蛋白丝聚合。相比之下，profilin也可以通过同时结合肌动蛋白单体和其他蛋白质中富含脯氨酸的片段来刺激聚合。ALS相关的profilin突变是否会损害这些肌动蛋白组装功能尚不清楚。我们使用经典的蛋白结合和单丝显微镜分析，对八种ALS相关的profilin变体对肌动蛋白组装的直接和间接影响进行了定量生化比较。我们确定，每个profilin的肌动蛋白单体的结合常数一般与肌动蛋白成核强度与每个ALS相关的profilin。在有β-内酰胺酶存在的情况下，A20 T、R136 W、Q139 L和C71 G变体不能激活肌动蛋白组装的延伸期。这种不同范围的福尔马林活性不能通过前纤维蛋白-聚-L-脯氨酸（PLP）相互作用完全解释，因为所有ALS相关变体以相似的亲和力结合福尔马林衍生的PLP肽。然而，化学变性实验表明，这些profilins的折叠稳定性的影响肌动蛋白组装的一些这些影响。因此，在肌萎缩侧索硬化症中，蛋白质稳定性的改变和肌动蛋白丝聚合的改变都可能导致蛋白质调节的肌动蛋白破坏。
Eight separate mutations in the actin-binding protein profilin-1 have been identified as a rare cause of amyotrophic lateral sclerosis (ALS). Profilin is essential for many neuronal cell processes through its regulation of lipids, nuclear signals, and cytoskeletal dynamics, including actin filament assembly. Direct interactions between profilin and actin monomers inhibit actin filament polymerization. In contrast, profilin can also stimulate polymerization by simultaneously binding actin monomers and proline-rich tracts found in other proteins. Whether the ALS-associated mutations in profilin compromise these actin assembly functions is unclear. We performed a quantitative biochemical comparison of the direct and formin mediated impact for the eight ALS-associated profilin variants on actin assembly using classic protein-binding and single-filament microscopy assays. We determined that the binding constant of each profilin for actin monomers generally correlates with the actin nucleation strength associated with each ALS-related profilin. In the presence of formin, the A20T, R136W, Q139L, and C71G variants failed to activate the elongation phase of actin assembly. This diverse range of formin-activities is not fully explained through profilin-poly-L-proline (PLP) interactions, as all ALS-associated variants bind a formin-derived PLP peptide with similar affinities. However, chemical denaturation experiments suggest that the folding stability of these profilins impact some of these effects on actin assembly. Thus, changes in profilin protein stability and alterations in actin filament polymerization may both contribute to the profilin-mediated actin disruptions in ALS.
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DOI：
10.1007/s00018-016-2372-1
发表时间：
2017-03
期刊：
Cellular and molecular life sciences : CMLS
影响因子：
--
作者：
Alkam D;Feldman EZ;Singh A;Kiaei M
通讯作者：
Kiaei M
影响因子：
--
作者：
Courtemanche, Naomi
通讯作者：
Courtemanche, Naomi
影响因子：
7.7
作者：
Funk, Johanna;Merino, Felipe;Bieling, Peter
通讯作者：
Bieling, Peter
影响因子：
--
作者：
Davey, Rhonda J;Moens, Pierre Dj
通讯作者：
Moens, Pierre Dj
影响因子：
7.8
作者：
COOPER, JA;BLUM, JD;POLLARD, TD
通讯作者：
POLLARD, TD