Multivalency enables unidirectional switch-like competition between intrinsically disordered proteins.
Multivalency enables unidirectional switch-like competition between intrinsically disordered proteins.
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多价性使内在无序蛋白质之间的单向开关状竞争成为可能。
DOI：
10.1073/pnas.2117338119
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发表时间：
2022-01-18
影响因子：
11.1
通讯作者：
Wright PE
中科院分区：
文献类型：
--
作者：
Berlow RB;Dyson HJ;Wright PE
内含子无序蛋白必须经常竞争结合到共享的相互作用中心，以执行其细胞功能。在这里，我们描述的机制，两个无序的蛋白质，调节缺氧的转录反应竞争结合折叠TAZ 1结构域的转录辅激活因子CBP和p300。CITED 2是HIF-1α的负反馈调节因子，以单向、开关样的方式从TAZ 1中取代HIF-1α。TAZ 1结构域结合的有效竞争高度依赖于HIF-1α和CITED 2激活结构域的灵活性和多价性。CITED 2和HIF-1α结合基序偶联强度的差异是单向性的关键决定因素，并强调了多价性在无序蛋白调节细胞过程中的作用。内源性无序蛋白必须竞争与共同的调控靶点结合以发挥其生物学功能。以前，我们发现两种无序蛋白质的激活结构域，转录因子HIF-1α及其负调节因子CITED 2，在缺氧条件下作为单向变构分子开关控制关键适应性基因的转录。这些蛋白质通过竞争与转录共激活因子CREB结合蛋白（CBP）和p300（CREB：环AMP反应元件结合蛋白）的TAZ 1结构域结合来实现转录控制。为了表征这种分子开关背后的机制细节，我们使用溶液NMR光谱和互补的生物物理方法来确定CITED 2中单个结合基序对整体竞争过程的贡献。CITED 2激活结构域的N-末端区域在与TAZ 1结合时形成螺旋，在启动与HIF-1α的竞争中起关键作用，该区域在高度依赖于竞争伙伴的动力学和无序的过程中形成三元复合物。CITED 2中的另外两个保守结合基序，LPEL基序和芳香/疏水基序，我们称之为CIFIC，协同作用以增强CITED 2的结合并抑制HIF-1α的再结合。当这些结合区域中的一个或多个被CITED 2肽的截短或突变改变时，HIF-1α和CITED 2之间的竞争的表观单向性丧失。我们的研究结果说明了分子相互作用的复杂性，涉及无序蛋白质含有多价相互作用基序，并提供了独特的机制，无序蛋白质竞争细胞内的共同分子靶点的占用洞察。
Intrinsically disordered proteins must frequently compete for binding to shared interaction hubs to perform their cellular functions. Here, we describe the mechanism by which two disordered proteins that regulate the transcriptional response to hypoxia compete for binding to the folded TAZ1 domain of the transcriptional coactivators CBP and p300. CITED2, a negative feedback regulator of HIF-1α, displaces HIF-1α from TAZ1 in a unidirectional, switch-like manner. Efficient competition for binding of the TAZ1 domain is highly dependent on the flexibility and multivalency of the HIF-1α and CITED2 activation domains. Differences in the strength of coupling of the CITED2 and HIF-1α binding motifs are key determinants of unidirectionality and underscore the role of multivalency in regulation of cellular processes by disordered proteins. Intrinsically disordered proteins must compete for binding to common regulatory targets to carry out their biological functions. Previously, we showed that the activation domains of two disordered proteins, the transcription factor HIF-1α and its negative regulator CITED2, function as a unidirectional, allosteric molecular switch to control transcription of critical adaptive genes under conditions of oxygen deprivation. These proteins achieve transcriptional control by competing for binding to the TAZ1 domain of the transcriptional coactivators CREB-binding protein (CBP) and p300 (CREB: cyclic-AMP response element binding protein). To characterize the mechanistic details behind this molecular switch, we used solution NMR spectroscopy and complementary biophysical methods to determine the contributions of individual binding motifs in CITED2 to the overall competition process. An N-terminal region of the CITED2 activation domain, which forms a helix when bound to TAZ1, plays a critical role in initiating competition with HIF-1α by enabling formation of a ternary complex in a process that is highly dependent on the dynamics and disorder of the competing partners. Two other conserved binding motifs in CITED2, the LPEL motif and an aromatic/hydrophobic motif that we term ϕC, function synergistically to enhance binding of CITED2 and inhibit rebinding of HIF-1α. The apparent unidirectionality of competition between HIF-1α and CITED2 is lost when one or more of these binding regions is altered by truncation or mutation of the CITED2 peptide. Our findings illustrate the complexity of molecular interactions involving disordered proteins containing multivalent interaction motifs and provide insight into the unique mechanisms by which disordered proteins compete for occupancy of common molecular targets within the cell.
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影响因子：
4.3
作者：
Ganguly D;Zhang W;Chen J
通讯作者：
Chen J
DOI：
10.1073/pnas.93.23.12969
发表时间：
1996-11-12
影响因子：
11.1
作者：
Arany, Z;Huang, LE;Livingston, DM
通讯作者：
Livingston, DM
影响因子：
4.3
作者：
Gerlach GJ;Carrock R;Stix R;Stollar EJ;Ball KA
通讯作者：
Ball KA
影响因子：
6.8
作者：
Fung HYJ;Birol M;Rhoades E
通讯作者：
Rhoades E
DOI：
10.1016/j.str.2021.07.011
发表时间：
2021-12-02
期刊：
Structure (London, England : 1993)
影响因子：
--
作者：
Appling FD;Berlow RB;Stanfield RL;Dyson HJ;Wright PE
通讯作者：
Wright PE