Thionins are plant-specific antimicrobial peptides that have been isolated from the endosperm and leaves of cereals, from the leaves of mistletoes, and from several other plant species. They are generally basic peptides with three or four disulfide bridges and a molecular mass of ~5 kDa. Thionins are produced as preproproteins consisting of a signal peptide, the thionin domain, and an acidic domain. Previously, only mature thionin peptides have been isolated from plants, and in addition to removal of the signal peptide, at least one cleavage processing step between the thionin and the acidic domain is necessary to release the mature thionin. In this work, we identified a thionin proprotein-processing enzyme (TPPE) from barley. Purification of the enzyme was guided by an assay that used a quenched fluorogenic peptide comprising the amino acid sequence between the thionin and the acidic domain of barley leaf-specific thionin. The barley TPPE was identified as a serine protease (BAJ93208) and expressed in Escherichia coli as a strep tag-labeled protein. The barley BTH6 thionin proprotein was produced in E. coli using the vector pETtrx1a and used as a substrate. We isolated and sequenced the BTH6 thionin from barley to confirm the N and C terminus of the peptide in planta. Using an in vitro enzymatic assay, the recombinant TPPE was able to process the quenched fluorogenic peptide and to cleave the acidic domain at least at six sites releasing the mature thionin from the proprotein. Moreover, it was found that the intrinsic three-dimensional structure of the BTH6 thionin domain prevents cleavage of the mature BTH6 thionin by the TPPE.
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http://dx.doi.org/10.1074/jbc.M115.647859 | DOI Listing |
Eur J Med Chem
January 2025
Key Laboratory for Green Chemical Process of Ministry of Education, School of Chemical Engineering and Pharmacy, Wuhan Institute of Technology, Wuhan, 430205, P. R. China. Electronic address:
SMARCA2 is an ATPase that regulates chromatin structure via ATP pathways, controlling cell division and differentiation. SMARCA2's bromodomain and ATPase domain, crucial for chromatin remodeling and cell regulation, are therapeutic targets in cancer treatment. This review explores the role of SMARCA2 in cancer development by studying its protein structure and physiological functions.
View Article and Find Full Text PDFPlant Physiol Biochem
January 2025
Key Laboratory of Resource Biology and Biotechnology in Western China (Ministry of Education), Shaanxi Provincial Key Laboratory of Biotechnology, College of Life Sciences, Northwest University, Xi'an, 710069, Shaanxi, People's Republic of China. Electronic address:
Point mutations were introduced into specific leucine (L) amino acids within the K domain of SHORT VEGETATIVE PHASE (SVP), and their effects on the SVP-AP1 interaction were assessed. Yeast two-hybrid experiments and β-galactosidase activity assays demonstrated that SVP maintained its capacity to interact with APETALA1 (AP1) despite point mutations at the 108th, 116th, 119th, and 127th leucine residues, where leucine was substituted with alanine (A). However, the mutation of the leucine residue at position 124 to alanine abolished the interaction between SVP and AP1 regardless of whether the mutation was singular or combined with others.
View Article and Find Full Text PDFArch Microbiol
January 2025
Department of Microbiology, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, Serdang, Selangor, 43400, Malaysia.
Bacteriophages produce endolysins at the end of the lytic cycle, which are crucial for lysing the host cells and releasing virion progeny. This lytic feature allows endolysins to act as effective antimicrobial alternatives when applied exogenously. Staphylococcal endolysins typically possess a modular structure with one or two enzymatically active N-terminal domains (EADs) and a C-terminal cell wall binding domain (CBD).
View Article and Find Full Text PDFNucleic Acids Res
January 2025
College of Life Sciences, Beijing Normal University, Beijing 100875, China.
Mammalian J-domain protein DNAJC9 interacts with histones H3-H4 and is important for cell proliferation. However, its exact function remains unclear. Here, we show that, in the fission yeast Schizosaccharomyces pombe, loss of Djc9, the ortholog of DNAJC9, renders the histone chaperone Asf1 no longer essential for growth.
View Article and Find Full Text PDFFront Immunol
January 2025
Key Laboratory of Freshwater Aquatic Genetic Resources, Ministry of Agriculture and Rural Affairs, Shanghai Ocean University, Shanghai, China.
Background: Shell and pearl formation in bivalves is a sophisticated biomineralization process that encompasses immunological and mineralization aspects, particularly during shell repair and the initial stages of pearl cultivation when a nucleus is inserted. Here, we describe a novel C-type lectin, HcLec1, isolated and characterized from the freshwater pearl mussel Lea.
Methods: Immune challenge, RNA interference (RNAi) experiments, ELISA, and antibacterial assays were employed to investigate the role of HcLec1 in innate immunity.
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