China
Africa
Explore chapters and articles related to this topic
Biological Strategies in Nanobiocatalyst Assembly
Published in Grunwald Peter, Biocatalysis and Nanotechnology, 2017
Ian Dominic F. Tabañag, Shen-Long Tsai
The leucine zipper domain (simply leucine zipper) is a structural motif which functions as a dimerization domain as well as its presence can generate adhesion forces between parallel a-helices; these are commonly found in transcription factors (e.g., DNA binding proteins). These a-helices consist of multiple leucine residues at approximately 7-residue intervals, which form an amphipathic alpha helix with a hydrophobic region running along one side as shown in Fig. 5.6. The structure of the leucine zipper was first hypothesized in the late 1980s by Landschulz et al. (1988) and has been further elucidated in the study of the structures of the fos and jun oncogenes, and the GCN4 transcription factor (Kouzarides and Ziff, 1989; Busch and Sassone-Corsi, 1990; Alber, 1992; O’Shea et al., 1993; Lumb and Kim, 1995).
Genetically Engineered Protein Domains as Hydrogel Crosslinks
Published in Raphael M. Ottenbrite, Sung Wan Kim, Polymeric Drugs & Drug Delivery Systems, 2019
Chun Wang, Russell J. Stewart, Russell J. Stewart, Jindrich KopeČek
The ability of coiled coils to form stable, specific oligomers has been most frequently used to engineer novel proteins. As a transplantable oligomerization module, native coiled-coil sequences of the dimeric leucine zipper have been used to construct highly avid antibodies [24, 25], epitope-displaying scaffold [26], and other novel chimeric proteins with biological and therapeutic importance [27–30]. Examples of using coiled coils as engineering materials are schematically depicted in Figure 2.
Roles of phytohormones in mitigating abiotic stress in plants induced by metal(loid)s As, Cd, Cr, Hg, and Pb
Published in Critical Reviews in Environmental Science and Technology, 2023
Zhi-Hua Dai, Dong-Xing Guan, Jochen Bundschuh, Lena Q. Ma
At the molecular level, Fan et al. (2014) reported that decreased Cd accumulation in ABA treatment correlates with the down-regulation of ABA-inhibited expression of iron-regulated transporter 1 (IRT1) in the roots of A. thaliana (Table 1), which is critical for Cd uptake in plants (Kobayashi & Nishizawa, 2012; Vert et al., 2002). However, Cd uptake in an IRT1-mutant fails to respond to ABA application, suggesting the important role of ABA in controlling Cd uptake in A. thaliana (Fan et al., 2014). Besides, the basic region/leucine zipper transcription factor abscisic acid-insensitive5 (ABI5) is involved in Cd accumulation. This is because its overexpression reduces whereas ABI5 mutant increases the Cd accumulation in A. thaliana (Zhang et al., 2019).
Protective effects of natural compounds against paraquat-induced pulmonary toxicity: the role of the Nrf2/ARE signaling pathway
Published in International Journal of Environmental Health Research, 2023
Hasan Badibostan, Nastaran Eizadi-Mood, A. Wallace Hayes, Gholamreza Karimi
The Nrf2 signaling pathway is one of the most important endogenous antioxidant systems (He et al. 2012; Jeon et al. 2016). Nrf2 and Keap1 (Kelch ECH associating protein 1) are two key signaling proteins that are activated during oxidative stress. Nrf2 is a master regulator of redox homeostasis, involved in the regulation of more than 500 genes, including genes that regulate oxidative stress. Nrf2 is a member of the vertebrate Cap’n’Collar (CNC) transcription factor subfamily of basic leucine zipper (bZip) transcription factors (Audousset et al. 2021). Keap1 is a cysteine-rich protein containing a total of 27 cysteine residues. Three of these residues, C151, C273, and C288, have been shown to play a key role in the nuclear translocation of Nrf2 (Kansanen et al. 2013). Dimeric Keap1 is responsible for the recognition of Nrf2 through two key motifs in the Neh2 domain of Nrf2. The Kelch domain of each Keap1 binds to the “DLG” and “ETGE” motifs of Nrf2. The main feature of Nrf2 is its rapid mobilization and nuclear translocation which suggest the mechanisms that regulate its cytoplasmic free concentration (Audousset et al. 2021).
Photochemical impacts on the toxicity of PM2.5
Published in Critical Reviews in Environmental Science and Technology, 2022
Jialin Xu, Wenxin Hu, Donghai Liang, Peng Gao
In contrast, more studies compared the toxicological differences between terpenoid VOCs and terpene-derived SOAs by in vitro experiments (Table 1). In general, isoprene-derived and α-pinene-derived SOAs have higher cytotoxicity than the original substances, which tend to aggravate the inflammation and oxidative stress in A549 cells (Doyle et al., 2004, 2007; Sexton et al., 2004). Doyle et al. (2004) exposed A549 cells to ISO and its photochemical products formed with NOx. Then, the cytotoxicity and Interleukin 8 (IL-8) gene expression levels were compared before and after the SOA formations. Compared with the original substances, terpene-derived SOAs showed significantly higher cytotoxicity and IL-8 expression, thus demonstrating elevated toxicity levels of ISO during photochemical reactions. Terpene-derived SOA exposure was observed to alter gene expression related to oxidative stress, with increased expression of nuclear factor erythroid 2-related factor 2 (Nrf-2) being the most obvious (Lin et al., 2016, 2017; Surratt et al., 2019). Nrf-2 is a basic leucine zipper transcription factor recognized as the core of the antioxidant defense. Combined with the antioxidant emergency element AU-rich element (ARE) through nuclear translocation, Nrf-2 can activate the transcription of downstream antioxidant enzymes, thereby regulating the oxidation/antioxidation balance and preventing the development of respiratory diseases (Cho et al., 2006; Ma, 2013). This further indicates that oxidative stress is induced by terpene-derived SOAs and provides the potential mechanism.