1.
Impact of novel N-aryl substituted piperamide on NF-kappa B translocation as a potent anti-neuroinflammatory agent.
Shahbazi, S, Zakerali, T, Frycz, B, Kaur, J
Biomedicine & pharmacotherapy = Biomedecine & pharmacotherapie. 2020;:110199
Abstract
NF-kB translocation is the key point in the upstream neuroinflammatory pathways. It plays an import role in the pro-inflammatory chemokine, cytokine, and various enzyme expressions, consequently leading to the inflammatory response of the innate immune system. The NF-kB complex consists of structural homolog subunits, including c-Rel, RelB, p52, p65, and p50. Among the p65 subunit has a vital function of NF-kB translocation and DNA binding. NF-kB translocation may occur due to acetylation and phosphorylation LYS 310 and SER311 amino acids in chain A of the p65 subunit in response to IKK-α/β activity. Therefore, there are two ways to inhibit the NF-kB translocation, either directly blocking the active sites of IKK-α/β enzymes or protecting the LYS 310 and SER311 of p65 subunit from acetylation and phosphorylation. NF-kB translocation inhibitors can maintain the NF-kB complex in the inactive form inside the cytosol. In this study, we have designed and developed an NF-kB translocation inhibitor, D4. We have performed various in silico, in vitro and in situ studies on the anti-neuroinflammatory function of D4. It showed the ability to inhibit IKK-α/β in both genome and proteome levels and protect LYS310 of the p65 subunit of NF-kB from the acetylation process. Therefore, we can suggest D4 as the promising anti-neuroinflammatory agent with a function on the upstream process of inflammatory pathways.
2.
Functional domains of SP110 that modulate its transcriptional regulatory function and cellular translocation.
Leu, JS, Chang, SY, Mu, CY, Chen, ML, Yan, BS
Journal of biomedical science. 2018;(1):34
-
-
Free full text
-
Abstract
BACKGROUND SP110, an interferon-induced nuclear protein, belongs to the SP100/SP140 protein family. Very recently, we showed that SP110b, an SP110 isoform, controls host innate immunity to Mycobacterium tuberculosis infection by regulating nuclear factor-κB (NF-κB) activity. However, it remains unclear how the structure of SP110 relates to its cellular functions. In this study, we provide experimental data illustrating the protein domains that are responsible for its functions. METHODS We examined the effects of SP110 isoforms and a series of deletion mutants of SP110 on transcriptional regulation by luciferase reporter assays. We also employed confocal microscopy to determine the cellular distributions of enhanced green fluorescent protein-tagged SP110 isoforms and SP110 mutants. In addition, we performed immunoprecipitation and Western blotting analyses to identify the regions of SP110 that are responsible for protein interactions. RESULTS Using reporter assays, we first demonstrated that SP110 isoforms have different regulatory effects on NF-κB-mediated transcription, supporting the notion that SP110 isoforms may have distinct cellular functions. Analysis of deletion mutants of SP110 showed that the interaction of the N-terminal fragment (amino acids 1-276) of SP110 with p50, a subunit of NF-κB, in the cytoplasm plays a crucial role in the down-regulation of the p50-driven tumor necrosis factor-α (TNFα) promoter activity in the nucleus, while the middle and C-terminal regions of SP110 localize it to various cellular compartments. Surprisingly, a nucleolar localization signal (NoLS) that contains one monopartite nuclear localization signal (NLS) and one bipartite NLS was identified in the middle region of SP110. The identification of a cryptic NoLS in the SP110 suggests that although this protein forms nuclear speckles in the nucleoplasm, it may be directed into the nucleolus to carry out distinct functions under certain cellular conditions. CONCLUSIONS The findings from this study elucidating the multidomain structure of the SP110 not only identify functional domains of SP110 that are required for transcriptional regulation, cellular translocation, and protein interactions but also implicate that SP110 has additional functions through its unexpected activity in the nucleolus.