Distinct functional constraints driving conservation of the cofilin N-terminal regulatory tail.
Distinct functional constraints driving conservation of the cofilin N-terminal regulatory tail.
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独特的功能限制驱动丝切蛋白 N 末端调控尾部的保护。
DOI：
10.1101/2023.06.30.547189
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发表时间：
2023
期刊：
影响因子：
--
通讯作者：
Turk,BenjaminE
中科院分区：
文献类型：
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作者：
Sexton,JoelA;Potchernikov,Tony;Bibeau,JeffreyP;Casanova-Sepúlveda,Gabriela;Cao,Wenxiang;Lou,HuaJane;Boggon,TitusJ;DeLaCruz,EnriqueM;Turk,BenjaminE
Cofilin家族蛋白通过丝状肌动蛋白的解聚和断裂在细胞骨架的重塑中起着至关重要的作用。Cofilin的短的、非结构化的N端区域是肌动蛋白结合的关键区域，也是抑制磷酸化的主要部位。与无序序列不同的是，N-末端区域高度保守，但驱动这种保守的具体方面尚不清楚。在这里，我们筛选了一个包含16,000个人类cofilin N-末端序列变体的文库，以了解它们支持Ins生长的能力。在有或没有上游调节因子LIM激酶的情况下酿酒。对单个变异体的筛选和生化分析的结果显示，对肌动蛋白结合和LIM激酶调节的不同序列要求。LIM激酶的识别只能部分解释对磷调节的序列限制，相反，这在很大程度上是由磷酸化失活cofilin的能力驱动的。我们发现肌动蛋白结合和磷酸抑制需要松散的序列，但总的来说，它们将N末端限制为在天然cofilin中发现的序列。我们的结果说明了磷酸化位点如何平衡潜在的相互竞争的序列要求的功能和调节。
Cofilin family proteins have essential roles in remodeling the cytoskeleton through filamentous actin depolymerization and severing. The short, unstructured N-terminal region of cofilin is critical for actin binding and harbors the major site of inhibitory phosphorylation. Atypically for a disordered sequence, the N-terminal region is highly conserved, but specific aspects driving this conservation are unclear. Here, we screen a library of 16,000 human cofilin N-terminal sequence variants for their capacity to support growth inS. cerevisiaein the presence or absence of the upstream regulator LIM kinase. Results from the screen and biochemical analysis of individual variants reveal distinct sequence requirements for actin binding and regulation by LIM kinase. LIM kinase recognition only partly explains sequence constraints on phosphoregulation, which are instead driven to a large extent by the capacity for phosphorylation to inactivate cofilin. We find loose sequence requirements for actin binding and phosphoinhibition, but collectively they restrict the N-terminus to sequences found in natural cofilins. Our results illustrate how a phosphorylation site can balance potentially competing sequence requirements for function and regulation.