Optogenetic Analysis of Allosteric Control in Protein Tyrosine Phosphatases
Optogenetic Analysis of Allosteric Control in Protein Tyrosine Phosphatases
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DOI：
10.1021/acs.biochem.0c00841
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发表时间：
2021-01-15
期刊：
影响因子：
2.9
通讯作者：
Fox, Jerome M.
中科院分区：
文献类型：
--
作者：
Hongdusit, Akarawin;Fox, Jerome M.
变构调节使得能够动态调整蛋白质功能，从而允许对细胞生物化学的严格控制。因此，相关蛋白质的变构系统中的差异可以揭示它们对有影响的刺激的敏感性的重要差异（例如，变构配体、突变或翻译后修饰）。本研究使用光遗传致动器作为工具，比较两种结构相关的调节蛋白：蛋白酪氨酸磷酸酶1B（PTP 1B）和T细胞蛋白酪氨酸磷酸酶（TCPTP）的变构系统。它从一个有趣的观察开始：蛋白质光开关与PTP 1B的变构影响α 7螺旋的融合允许其催化活性的光学调制，但与TCPTP的类似融合则不然。随后对不同PTP嵌合体的分析表明，用PTP 1B的同源区域取代TCPTP的区域可以增强光控制;随着TCPTP变得更加“类似PTP 1B”，其光敏性增加。有趣的是，光控所需的结构变化也增强了TCPTP对其他变构输入的敏感性，特别是变构抑制剂和新报道的激活突变。我们的研究结果表明，变构功能的α 7螺旋的PTP 1B是不保守的PTP家族和突出的残基转移到其他PTP的功能。更广泛地说，我们的研究结果表明，简单的基因融合事件可以加强个别蛋白质结构域内的变构通信，并描述了一个有趣的应用光遗传学执行器作为结构探针-一种物理破坏性的“棘轮”-研究蛋白质变构。
Allosteric regulation enables dynamic adjustments to protein function that permit tight control over cellular biochemistry. Discrepancies in the allosteric systems of related proteins can thus reveal important differences in their susceptibilities to influential stimuli (e.g., allosteric ligands, mutations, or post-translational modifications). This study uses an optogenetic actuator as a tool to compare the allosteric systems of two structurally related regulatory proteins: protein tyrosine phosphatase 1B (PTP1B) and T-cell protein tyrosine phosphatase (TCPTP). It begins with an interesting observation: The fusion of a protein light switch to the allosterically influential alpha 7 helix of PTP1B permits optical modulation of its catalytic activity, but a similar fusion to TCPTP does not. A subsequent analysis of different PTP chimeras shows that replacing regions of TCPTP with homologous regions from PTP1B can enhance photocontrol; as TCPTP becomes more "PTP1B-like", its photosensitivity increases. Interestingly, the structural changes required for photocontrol also enhance the sensitivity of TCPTP to other allosteric inputs, notably, an allosteric inhibitor and a newly reported activating mutation. Our findings indicate that the allosteric functionality of the alpha 7 helix of PTP1B is not conserved across the PTP family and highlight residues necessary to transfer this functionality to other PTPs. More broadly, our results suggest that simple gene fusion events can strengthen allosteric communication within individual protein domains and describe an intriguing application for optogenetic actuators as structural probes-a sort of physically disruptive "ratchet"-for studying protein allostery.