Deletion of Specific Conserved Motifs from the N-Terminal Domain of αB-Crystallin Results in the Activation of Chaperone Functions.
Deletion of Specific Conserved Motifs from the N-Terminal Domain of αB-Crystallin Results in the Activation of Chaperone Functions.
复制标题
DOI：
10.3390/ijms23031099
复制
发表时间：
2022-01-20
影响因子：
5.6
通讯作者：
Sharma KK
中科院分区：
文献类型：
--
作者：
Mahalingam S;Shankar G;Mooney BP;Singh K;Santhoshkumar P;Sharma KK
α-晶状体蛋白（αA-和αB-）的较小寡聚分子伴侣因其在预防蛋白质聚集疾病方面的治疗潜力而受到越来越多的关注。我们之前的研究表明，从 αB-晶状体蛋白 (αBΔ54-61) 的 N 端结构域 (NTD) 中删除 54-61 个残基会减小寡聚体的大小并增强伴侣功能。多项研究还表明 NTD 在蛋白质寡聚化和伴侣功能中发挥着重要作用。本研究旨在评估从活化的αBΔ54-61中删除保守的21-28个残基（得到αBΔ21-28、Δ54-61）对重组αBΔ21-28、Δ54-61的结构功能的影响。与 αB-WT 相比，αBΔ21–28、Δ54–61 突变体的寡聚物大小减少了 80%，针对模型底物的分子伴侣活性增加了 3 至 25 倍。此外，αBΔ21–28、Δ54–61 被发现可以在体外防止 β-淀粉样蛋白 (Aβ1–42) 原纤维形成，并比 αB-WT 或 αBΔ54–61 更有效地抑制 ARPE-19 细胞中 Aβ1–42 诱导的细胞毒性。使用碘酸钠 (SI) 进行的细胞毒性和活性氧 (ROS) 检测研究表明，在氧化应激细胞中，双突变蛋白比野生型或 αBΔ54-61 具有更高的抗凋亡和抗氧化活性。我们的研究表明，αB-晶状体蛋白中的残基 21-28 和 54-61 有助于寡聚化并调节伴侣功能。删除保守的 21-28 个残基进一步增强了激活的 αBΔ54-61。我们认为，底物亲和力的增加、亚基结构的改变以及导致更小的寡聚物的组装可能是αBΔ21-28、Δ54-61的分子伴侣活性增加的原因。
Smaller oligomeric chaperones of α-crystallins (αA- and αB-) have received increasing attention due to their improved therapeutic potential in preventing protein aggregating diseases. Our previous study suggested that deleting 54–61 residues from the N-terminal domain (NTD) of αB-crystallin (αBΔ54–61) decreases the oligomer size and increases the chaperone function. Several studies have also suggested that NTD plays a significant role in protein oligomerization and chaperone function. The current study was undertaken to assess the effect of deleting conserved 21–28 residues from the activated αBΔ54–61 (to get αBΔ21–28, Δ54–61) on the structure–function of recombinant αBΔ21–28, Δ54–61. The αBΔ21–28, Δ54–61 mutant shows an 80% reduction in oligomer size and 3- to 25-fold increases in chaperone activity against model substrates when compared to αB-WT. Additionally, the αB∆21–28, ∆54–61 was found to prevent β-amyloid (Aβ1–42) fibril formation in vitro and suppressed Aβ1–42-induced cytotoxicity in ARPE-19 cells in a more effective manner than seen with αB-WT or αB∆54–61. Cytotoxicity and reactive oxygen species (ROS) detection studies with sodium iodate (SI) showed that the double mutant protein has higher anti-apoptotic and anti-oxidative activities than the wild-type or αB∆54–61 in oxidatively stressed cells. Our study shows that the residues 21–28 and 54–61 in αB-crystallin contribute to the oligomerization and modulate chaperone function. The deletion of conserved 21–28 residues further potentiates the activated αBΔ54–61. We propose that increased substrate affinity, altered subunit structure, and assembly leading to smaller oligomers could be the causative factors for the increased chaperone activity of αBΔ21–28, Δ54–61.
登录
查看更多内容
影响因子：
5.6
作者：
Ahmad, Md. Falz;Raman, Bakthisaran;Rao, Ch. Mohan
通讯作者：
Rao, Ch. Mohan
影响因子：
2
作者：
Dasari B;Prasanthi JR;Marwarha G;Singh BB;Ghribi O
通讯作者：
Ghribi O
影响因子：
9
作者：
通讯作者：
--
影响因子：
4.4
作者：
Mones, Jordi;Leiva, Marta;Fernandez, Eduardo
通讯作者：
Fernandez, Eduardo
影响因子：
25
作者：
Cleary, JP;Walsh, DM;Ashe, KH
通讯作者：
Ashe, KH