Structure and function analysis of Arabidopsis thaliana SRO protein family

Background: Heart failure is a growing cause of human morbidity and mortality. Supplementations of free radical scavenging antioxidants have largely failed to protect the myocardium from oxidative stress diseases. While endogenous transcriptional activation of antioxidants appears to be promising, their chronic effects are unknown. Here, we tested a hypothesis that chronic activation of antioxidant system will result in reductive stress (RS) and lead to pathological cardiac hypertrophy. Methods: Novel transgenic (TG) mice expressing constitutively active Nrf2 in the heart (α-MHC-caNrf2-TG) and their littermates were used to study the effects on structure and function of the myocardium. Myocardial glutathione redox state (GSH/GSSG), transcript levels (qPCR), and protein (immunoblotting) for Nrf2-related antioxidants and structure and function analysis (echocardiography - Vevo2100 Imager) in Non-transgenic (NTg), TG-low and TG-high mice (n=6-12/gp.) were performed at 6-8 months of age. Further, changes in cardiomyocytes and rate of survival in TG mice were analyzed. Results: Kaplan-Meier survival plots demonstrated 10 and 40% mortality in TG-low and TG-high, respectively, compared to NTG by 60 weeks of age. The myocardial glutathione and its redox ratio (GSH/GSSG) were significantly increased (p<0.05) in the TG-low and TG-high compared with NTg mice indicates development of RS. A significant increase in Nrf2-ARE (promoter) binding with increased expression of antioxidant genes and proteins (p<0.05) were noted in TG vs. NTg mice. Increased heart-to-body weight and heart weight to tibia length ratios were prominent in TG-high relative to NTg or TG-low mice. Histological analyses (WGA, H&E staining) showed increased cardiomyocyte size, ventricular wall thickening and decreased chamber volume in TG mice. Echocardiography analyses revealed significant hypertrophic cardiomyopathy with abnormally increased ejection fraction (HCM i EF) due to chronic reductive stress. Conclusion: Thus, basal attenuation of the obligatory oxidative signaling with chronic activation of Nrf2-antioxidants could shift the redox equilibrium to “reductive” side and thereby causing pathological cardiac remodeling.

Download Full-text

Advances in Understanding the Acyl-CoA-Binding Protein in Plants, Mammals, Yeast, and Filamentous Fungi

Journal of Fungi ◽

10.3390/jof6010034 ◽

2020 ◽

Vol 6 (1) ◽

pp. 34

Author(s):

Shangkun Qiu ◽

Bin Zeng

Keyword(s):

Arabidopsis Thaliana ◽

Oryza Sativa ◽

Filamentous Fungi ◽

Fungal Pathogens ◽

Binding Protein ◽

Structure And Function ◽

Monascus Ruber ◽

Binding Characteristics ◽

And Function ◽

High Binding Affinity

Acyl-CoA-binding protein (ACBP) is an important protein with a size of about 10 kDa. It has a high binding affinity for C12–C22 acyl-CoA esters and participates in lipid metabolism. ACBP and its family of proteins have been found in all eukaryotes and some prokaryotes. Studies have described the function and structure of ACBP family proteins in mammals (such as humans and mice), plants (such as Oryza sativa, Arabidopsis thaliana, and Hevea brasiliensis) and yeast. However, little information on the structure and function of the proteins in filamentous fungi has been reported. This article concentrates on recent advances in the research of the ACBP family proteins in plants and mammals, especially in yeast, filamentous fungi (such as Monascus ruber and Aspergillus oryzae), and fungal pathogens (Aspergillus flavus, Cryptococcus neoformans). Furthermore, we discuss some problems in the field, summarize the binding characteristics of the ACBP family proteins in filamentous fungi and yeast, and consider the future of ACBP development.

Download Full-text

Plant Histone HTB (H2B) Variants in Regulating Chromatin Structure and Function

Plants ◽

10.3390/plants9111435 ◽

2020 ◽

Vol 9 (11) ◽

pp. 1435

Author(s):

Janardan Khadka ◽

Anat Pesok ◽

Gideon Grafi

Keyword(s):

Arabidopsis Thaliana ◽

Chromatin Structure ◽

Developmental Stages ◽

Histone Variants ◽

Structure And Function ◽

Core Histone ◽

Histone H2b ◽

Histone Proteins ◽

Genes Encoding ◽

And Function

Besides chemical modification of histone proteins, chromatin dynamics can be modulated by histone variants. Most organisms possess multiple genes encoding for core histone proteins, which are highly similar in amino acid sequence. The Arabidopsis thaliana genome contains 11 genes encoding for histone H2B (HTBs), 13 for H2A (HTAs), 15 for H3 (HTRs), and 8 genes encoding for histone H4 (HFOs). The finding that histone variants may be expressed in specific tissues and/or during specific developmental stages, often displaying specific nuclear localization and involvement in specific nuclear processes suggests that histone variants have evolved to carry out specific functions in regulating chromatin structure and function and might be important for better understanding of growth and development and particularly the response to stress. In this review, we will elaborate on a group of core histone proteins in Arabidopsis, namely histone H2B, summarize existing data, and illuminate the potential function of H2B variants in regulating chromatin structure and function in Arabidopsis thaliana.

Download Full-text

467 In-silico structure and function analysis of the hepatitis C virus non-structural protein 4B (NS4B)

Journal of Hepatology ◽

10.1016/s0168-8278(05)81879-3 ◽

2005 ◽

Vol 42 ◽

pp. 169

Keyword(s):

Hepatitis C Virus ◽

Hepatitis C ◽

In Silico ◽

Function Analysis ◽

Structure And Function ◽

Structural Protein ◽

And Function

Download Full-text

Bifunctional Chloroplastic DJ-1B from Arabidopsis thaliana is an Oxidation-Robust Holdase and a Glyoxalase Sensitive to H2O2

Antioxidants ◽

10.3390/antiox8010008 ◽

2019 ◽

Vol 8 (1) ◽

pp. 8 ◽

Cited By ~ 4

Author(s):

Aleksandra Lewandowska ◽

Trung Nghia Vo ◽

Thuy-Dung Ho Nguyen ◽

Khadija Wahni ◽

Didier Vertommen ◽

...

Keyword(s):

Oxidative Stress ◽

Arabidopsis Thaliana ◽

Secondary Structure ◽

Structure And Function ◽

Transcript Levels ◽

Chaperone Function ◽

Multifunctional Enzymes ◽

And Function ◽

Discrete Functions

Members of the DJ-1 protein family are multifunctional enzymes whose loss increases the susceptibility of the cell to oxidative stress. However, little is known about the function of the plant DJ-1 homologs. Therefore, we analyzed the effect of oxidation on the structure and function of chloroplastic AtDJ-1B and studied the phenotype of T-DNA lines lacking the protein. In vitro oxidation of AtDJ-1B with H2O2 lowers its glyoxalase activity, but has no effect on its holdase chaperone function. Remarkably, upon oxidation, the thermostability of AtDJ-1B increases with no significant alteration of the overall secondary structure. Moreover, we found that AtDJ-1B transcript levels are invariable, and loss of AtDJ-1B does not affect plant viability, growth and stress response. All in all, two discrete functions of AtDJ-1B respond differently to H2O2, and AtDJ-1B is not essential for plant development under stress.

Download Full-text