Division of Biochemistry and Structural Biology, CSIR-Central Drug Research Institute, Lucknow, Uttar Pradesh, India.
Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, Uttar Pradesh, India.
Infect Immun. 2024 Oct 15;92(10):e0023424. doi: 10.1128/iai.00234-24. Epub 2024 Sep 9.
Chaperonins/Heat shock protein 60 are ubiquitous multimeric protein complexes that assist in the folding of partially and/or misfolded proteins using metabolic energy into their native stage. The eukaryotic group II chaperonin, also referred as T-complex protein-1 ring complex (TRiC)/T-complex protein-1 (TCP1)/chaperonin containing T-complex protein (CCT), contains 8-9 paralogous subunits, arranged in each of the two rings of hetero-oligomeric complex. In , till date, only one subunit, LdTCP1γ, has been well studied. Here, we report the molecular, structural, and functional characterization of TCP1δ subunit of (LdTCP1δ), the causative agent of Indian kala-azar. LdTCP1δ gene exhibited only 27.9% identity with LdTCP1γ and clustered in a separate branch in the phylogenic tree of LdTCP1 subunits. The purified recombinant protein formed a high molecular weight complex (0.75 MDa), arranged into 16-mer assembly, and performed chaperonin activity as assayed by ATP-dependent luciferase folding. LdTCP1δ exhibits 1.8-fold upregulated expression in metabolically active, rapidly dividing log phase promastigotes. Over-expression of LdTCP1δ in promastigotes results in increased infectivity and rate of multiplication of intracellular amastigotes. The study thus establishes the existence of an individual functionally active homo-oligomeric complex of LdTCP1δ chaperonin with its role in parasite infectivity and multiplication.
伴侣蛋白/热休克蛋白 60 是普遍存在的多聚体蛋白复合物，它利用代谢能量将部分折叠和/或错误折叠的蛋白质辅助折叠成其天然状态。真核生物组 II 伴侣蛋白，也称为 T 复合物蛋白-1 环复合物（TRiC）/T 复合物蛋白-1（TCP1）/含 T 复合物蛋白的伴侣蛋白（CCT），包含 8-9 个同源的亚基，排列在异源寡聚复合物的两个环中。在，到目前为止，只有一个亚基，LdTCP1γ，得到了很好的研究。在这里，我们报告了（LdTCP1δ）的 TCP1δ 亚基的分子、结构和功能特征，LdTCP1δ 是印度黑热病的病原体。LdTCP1δ 基因与 LdTCP1γ 的同一性仅为 27.9%，并在 LdTCP1 亚基的系统发育树中聚类在一个单独的分支中。纯化的重组蛋白形成一个高分子量的复合物（0.75 MDa），排列成 16 聚体组装，并表现出 ATP 依赖性荧光素酶折叠的伴侣蛋白活性。LdTCP1δ 在代谢活跃、快速分裂的对数期前鞭毛体中的表达上调了 1.8 倍。LdTCP1δ 在前鞭毛体中的过表达导致细胞内无鞭毛体的感染力和增殖率增加。该研究因此确立了 LdTCP1δ 伴侣蛋白的单个功能活性同型寡聚复合物的存在及其在寄生虫感染力和增殖中的作用。
