Redox-dependent thiol-disulfide switches of cysteine residues are one of the significant posttranslational modifications of proteins to control rapidly their stability, activity, and protein interaction. Redox control also modulates the tetrapyrrole biosynthesis (TBS). Among the redox-dependent TBS enzymes, 5-aminolevulinic acid dehydratase (ALAD) was previously recognized to interact with reductants, such a thioredoxins or NADPH-dependent thioredoxin reductase C. In this report, we aim to verify the redox sensitivity of ALAD and identify the redox-reactive cysteine residues among the six cysteines of the mature protein form Arabidopsis. Based on structural modelling and comparative studies of wild-type ALAD and ALAD mutants with single and double Cys➔Ser substitutions under oxidizing and reducing conditions, we aim to predict the dimerization and oligomerisation of ALAD as well as the crucial Cys residues for disulfide bridge formation and enzyme activity. The Cys404Ser mutation led to a drastic inactivation of ALAD and redox-dependent properties of ALAD were severely impaired, when Cys71 was simultaneously mutated with Cys152 or Cys251. Cys71 is located in a flexible N-terminal arm of ALAD, which could allow intramolecular disulfide bridges with Cys residues at the surface of the remaining globule ALAD structure. As a result, we propose different roles of Cys residues for redox control, catalytic activity and Mg-dependent assembly.
Download full-text PDF |
Source |
|---|---|
| http://www.ncbi.nlm.nih.gov/pmc/articles/PMC10839789 | PMC |
| http://dx.doi.org/10.3389/fpls.2023.1294802 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Structural insights into the role of reduced cysteine residues in SOD1 amyloid filament formation.
Proc Natl Acad Sci U S A
February 2025
Department of Agricultural Biotechnology, and Research Institute of Agriculture and Life Sciences, CALS, Seoul National University, Seoul 08826, Republic of Korea.
The formation of superoxide dismutase 1 (SOD1) filaments has been implicated in amyotrophic lateral sclerosis (ALS). Although the disulfide bond formed between Cys57 and Cys146 in the active state has been well studied, the role of the reduced cysteine residues, Cys6 and Cys111, in SOD1 filament formation remains unclear. In this study, we investigated the role of reduced cysteine residues by determining and comparing cryoelectron microscopy (cryo-EM) structures of wild-type (WT) and C6A/C111A SOD1 filaments under thiol-based reducing and metal-depriving conditions, starting with protein samples possessing enzymatic activity.
View Article and Find Full Text PDFThe role of canopy family proteins: biological mechanism and disease function.
Mol Biol Rep
January 2025
Department of Gastroenterology, Beijing Friendship Hospital, Capital Medical University, No. 95, Yong An Road, Xi Cheng District, Beijing, 100050, China.
Canopy family proteins are highly sequence-conserved proteins with an N-terminal hydrophobic signal sequence, a unique pattern of six cysteine residues characteristic of the saposin-like proteins, and a C-terminal putative endoplasmic reticulum retention signal sequence. At present, the known canopy family proteins are canopy fibroblast growth factor signaling regulator 1 (CNPY1), CNPY2, CNPY3, and CNPY4. Despite similar structures, canopy family proteins regulate complex signal networks to participate in various biological processes.
View Article and Find Full Text PDFSynthetic studies of the mutant proinsulin syndrome demonstrate correlation between folding efficiency and age of diabetes onset.
Int J Pept Res Ther
January 2025
Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN, United States 46202.
Purpose: Heterozygous mutations in the insulin gene can give rise to a monogenic diabetes syndrome due to toxic misfolding of the variant proinsulin in the endoplasmic reticulum (ER) of pancreatic β-cells. Clinical mutations are widely distributed in the sequence (86 amino acids). Misfolding induces chronic ER stress and interferes in with wildtype biosynthesis and secretion.
View Article and Find Full Text PDFHeat stress induces oxidative stress and activates the KEAP1-NFE2L2-ARE pathway in reproduction-related cells.
Anim Sci J
January 2025
Laboratory of Animal Breeding and Reproduction, Research Faculty of Agriculture, Hokkaido University, Sapporo, Japan.
Heat stress negatively affects the reproductive function of in animals and humans. Although a relationship between heat and oxidative stress has been suggested, the underlying mechanism has not been sufficiently examined in reproduction-related cells. Therefore, we aimed to investigate whether heat stress induces oxidative stress using a variety of reproduction-related cells including bovine placental and cumulus-granulosa cells, human cell lines derived from cervical and endometrial cancers, and fibroblasts derived from endometrium.
View Article and Find Full Text PDFAncestral Sequence Reconstruction and Comprehensive Computational Simulations Unmask an Efficient PET Hydrolase with the Wobbled Catalytic Triad.
ChemSusChem
January 2025
Nanjing Normal University, School of Food Science and Pharmaceutical Engineering, No. 2 Xuelin Road, 210023, Nanjing, CHINA.
Beyond directed evolution, ancestral sequence reconstruction (ASR) has emerged as a powerful strategy for engineering proteins with superior functional properties. Herein, we harnessed ASR to uncover robust PET hydrolase variants, expanding the repertoire of PET-degrading enzymes and providing deeper insights into the underlying mechanisms of PET hydrolysis. As a result, ASR1-PETase, featuring a unique cysteine catalytic site, was discovered.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!