scholarly journals MrHex1 is Required for Woronin Body Formation, Fungal Development and Virulence in Metarhizium robertsii

2020 ◽  
Vol 6 (3) ◽  
pp. 172 ◽  
Author(s):  
Guirong Tang ◽  
Yanfang Shang ◽  
Shiqing Li ◽  
Chengshu Wang
Keyword(s):  
Protein A ◽  
Fungal Species ◽  
Growth Defect ◽  
Dense Core Vesicle ◽  
Amino Acid Residues ◽  
Cell Integrity ◽  
Metarhizium Robertsii ◽  
Self Assembling ◽  
Woronin Body ◽  
Septal Pores

The Woronin body (WB) is a peroxisome-derived dense-core vesicle, a self-assembling hexagonal crystal of a single protein Hex1. This organelle is specific to the ascomycete fungi belonging to the Pezizomycotina subphylum by functioning in sealing septal pores in response to mycelium damage and the control of cell heterogeneity. We retrieved all available Hex1-domain containing proteins of different fungi from the GenBank database and found considerable length variations among 460 obtained Hex1 proteins. However, a highly conserved Hex1 domain containing 75 amino acid residues with a specific S/A-R/S-L consensus motif for targeting peroxisome is present at the carboxy-terminus of each protein. A homologous Hex1 gene, named MrHex1, was deleted in the entomopathogenic fungus Metarhizium robertsii. It was found that MrHex1 was responsible for WB formation in M. robertsii and involved in sealing septal pores to maintain cell integrity and heterogeneity. Different assays indicated that, relative to the wild-type (WT) strain, ∆Mrhex1 demonstrated a growth defect on a solid medium and substantial reductions of conidiation, appressorium formation and topical infectivity against insect hosts. However, there was no obvious virulence difference between WT and mutants during injection of insects. We also found that ∆MrHex1 could tolerate different stress conditions like the WT and the gene-rescued mutant of M. robertsii, which is in contrast to the reports of the stress-response defects of the Hex1 null mutants of other fungal species. In addition to revealing the phenotypic/functional alterations of the Hex1 deletion mutants between different pathotype fungi, the results of this study may benefit the understanding of the evolution and WB-control of fungal entomopathogenicity.

scholarly journals Degradation of Fungal MicroRNAs Triggered by Short Tandem Target Mimics Is via the Small-RNA-Degrading Nuclease

2019 ◽  
Vol 85 (9) ◽  
Author(s):  
Yulong Wang ◽  
Zhangxun Wang ◽  
Wenjing Yang ◽  
Xiangyun Xie ◽  
Haiyan Cheng ◽  
...  
Keyword(s):  
Small Rna ◽  
Target Genes ◽  
Rna Binding ◽  
Fungal Species ◽  
Metarhizium Robertsii ◽  
Content Type ◽  
Rna Molecules ◽  
Significant Difference ◽  
Pol Iii ◽  
Short Tandem

ABSTRACT MicroRNAs (miRNAs) have been recognized as sequence-specific regulators of the genome, transcriptome, and proteome in eukaryotes. However, the functions and working mechanisms of hundreds of fungal miRNA-like (miR-like) RNAs are obscure. Here, we report that a short tandem target mimic (STTM) triggered the degradation of several fungal miR-like RNAs in two different fungal species, Metarhizium robertsii and Aspergillus flavus, and that small-RNA-degrading nucleases (SDNs) were indispensable for such degradation. STTMs were most effective when the fungal polymerase II (Pol II) promoter was used for their expression, while the Pol III promoter was less effective. The length of the STTM spacer, approximately 48 to 96 nucleotides, and the number of miR-like RNA binding sites, from 2 to 4 copies, showed no significant difference in the degradation of miR-like RNAs. STTMs modulated the miR-like RNA expression levels in at least two different fungal species, which further impacted fungal asexual growth and sporulation. Further analysis showed that the degraded miR-like RNAs in STTM mutants led to the upregulation of potential target genes involved in fungal development and conidial production, which result in different phenotypes in these mutants. The STTM technology developed in this study is an effective and powerful tool for the functional dissection of fungal miR-like RNAs. IMPORTANCE The development and application of STTM technology to block miR-like RNAs in M. robertsii and A. flavus may allow for efficient generation of miR-like RNA mutants in various fungi, providing a powerful tool for functional genomics of small RNA molecules in fungi.

scholarly journals Contribution of Trafficking Signals in the Cytoplasmic Tail of the Infectious Bronchitis Virus Spike Protein to Virus Infection

2005 ◽  
Vol 79 (21) ◽  
pp. 13209-13217 ◽  
Author(s):  
Soonjeon Youn ◽  
Ellen W. Collisson ◽  
Carolyn E. Machamer
Keyword(s):  
Virus Infection ◽  
Infectious Bronchitis Virus ◽  
Secretory Pathway ◽  
Protein A ◽  
Cytoplasmic Tail ◽  
Growth Defect ◽  
Target Cells ◽  
Cdna Clones ◽  
S Protein ◽  
Infectious Bronchitis

ABSTRACT Coronavirus spike (S) proteins are responsible for binding and fusion with target cells and thus play an essential role in virus infection. Recently, we identified a dilysine endoplasmic reticulum (ER) retrieval signal and a tyrosine-based endocytosis signal in the cytoplasmic tail of the S protein of infectious bronchitis virus (IBV). Here, an infectious cDNA clone of IBV was used to address the importance of the S protein trafficking signals to virus infection. We constructed infectious cDNA clones lacking the ER retrieval signal, the endocytosis signal, or both. The virus lacking the ER retrieval signal was viable. However, this virus had a growth defect at late times postinfection and produced larger plaques than IBV. Further analysis confirmed that the mutant S protein trafficked though the secretory pathway faster than wild-type S protein. A more dramatic phenotype was obtained when the endocytosis signal was mutated. Recombinant viruses lacking the endocytosis signal (in combination with a mutated dilysine signal or alone) could not be recovered, even though transient syncytia were formed in transfected cells. Our results suggest that the endocytosis signal of IBV S is essential for productive virus infection.

scholarly journals The structure of the cysteine protease and lectin-like domains of Cwp84, a surface layer-associated protein fromClostridium difficile

2014 ◽  
Vol 70 (7) ◽  
pp. 1983-1993 ◽  
Author(s):  
William J. Bradshaw ◽  
Jonathan M. Kirby ◽  
Nethaji Thiyagarajan ◽  
Christopher J. Chambers ◽  
Abigail H. Davies ◽  
...  
Keyword(s):  
Surface Layer ◽  
Cysteine Protease ◽  
Cathepsin L ◽  
Protein A ◽  
Surface Protein ◽  
Carbohydrate Binding ◽  
Amino Acid Residues ◽  
Strong Base ◽  
Bacterial Surface ◽  
Single Polypeptide

Clostridium difficileis a major problem as an aetiological agent for antibiotic-associated diarrhoea. The mechanism by which the bacterium colonizes the gut during infection is poorly understood, but undoubtedly involves a myriad of components present on the bacterial surface. The mechanism ofC. difficilesurface-layer (S-layer) biogenesis is also largely unknown but involves the post-translational cleavage of a single polypeptide (surface-layer protein A; SlpA) into low- and high-molecular-weight subunits by Cwp84, a surface-located cysteine protease. Here, the first crystal structure of the surface protein Cwp84 is described at 1.4 Å resolution and the key structural components are identified. The truncated Cwp84 active-site mutant (amino-acid residues 33–497; C116A) exhibits three regions: a cleavable propeptide and a cysteine protease domain which exhibits a cathepsin L-like fold followed by a newly identified putative carbohydrate-binding domain with a bound calcium ion, which is referred to here as a lectin-like domain. This study thus provides the first structural insights into Cwp84 and a strong base to elucidate its role in theC. difficileS-layer maturation mechanism.

scholarly journals Woronin body-based sealing of septal pores

2017 ◽  
Vol 109 ◽  
pp. 53-55 ◽  
Author(s):  
Gero Steinberg ◽  
Nicholas J. Harmer ◽  
Martin Schuster ◽  
Sreedhar Kilaru
Keyword(s):  
Woronin Body ◽  
Septal Pores

Evidence for direct CFTR inhibition by CFTRinh-172 based on Arg347 mutagenesis

2008 ◽  
Vol 413 (1) ◽  
pp. 135-142 ◽  
Author(s):  
Emanuela Caci ◽  
Antonella Caputo ◽  
Alexandre Hinzpeter ◽  
Nicole Arous ◽  
Pascale Fanen ◽  
...  
Keyword(s):  
Amino Acids ◽  
Transmembrane Helix ◽  
Protein A ◽  
Transmembrane Conductance Regulator ◽  
Amino Acid Residues ◽  
Transmembrane Conductance ◽  
Inhibitory Potency ◽  
Functional Assays ◽  
Cftr Protein ◽  
Cystic Fibrosis Transmembrane

CFTR (cystic fibrosis transmembrane conductance regulator) is an epithelial Cl− channel inhibited with high affinity and selectivity by the thiazolidinone compound CFTRinh-172. In the present study, we provide evidence that CFTRinh-172 acts directly on the CFTR. We introduced mutations in amino acid residues of the sixth transmembrane helix of the CFTR protein, a domain that has an important role in the formation of the channel pore. Basic and hydrophilic amino acids at positions 334–352 were replaced with alanine residues and the sensitivity to CFTRinh-172 was assessed using functional assays. We found that an arginine-to-alanine change at position 347 reduced the inhibitory potency of CFTRinh-172 by 20–30-fold. Mutagenesis of Arg347 to other amino acids also decreased the inhibitory potency, with aspartate producing near total loss of CFTRinh-172 activity. The results of the present study provide evidence that CFTRinh-172 interacts directly with CFTR, and that Arg347 is important for the interaction.

scholarly journals Molecular cloning and characterization of the cDNA coding for C4b-binding protein, a regulatory protein of the classical pathway of the human complement system

1985 ◽  
Vol 230 (1) ◽  
pp. 133-141 ◽  
Author(s):  
L P Chung ◽  
D R Bentley ◽  
K B Reid
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Amino Acid Sequence ◽  
Cdna Sequence ◽  
Binding Protein ◽  
Regulatory Protein ◽  
Protein A ◽  
Classical Pathway ◽  
Amino Acid Residues ◽  
Cloned Cdna

By using synthetic oligonucleotides as probes, plasmid clones containing portions of cDNA coding for human C4b-binding protein were isolated from a liver cDNA library. The entire amino acid sequence of the C4b-binding protein can be predicted from this study of the cloned cDNA when allied to a previous sequence study at the protein level [Chung, Gagnon & Reid (1985) Mol. Immunol. 22, 427-435], in which over 55% of the amino acid sequence, including the N-terminal 62 residues, was obtained. The plasmid clones isolated allowed the unambiguous determination of 1717 nucleotides of cDNA sequence between the codon for the 32nd amino acid in the sequence of C4b-binding protein and the 164th nucleotide in the 3′ non-translated region. The sequence studies show that the secreted form of C4b-binding protein, found in plasma, is composed of chains of apparent Mr 70 000 that contains 549 amino acid residues. Examination of the protein and cDNA sequence results show that there are at least two polymorphic sites in the molecule. One is at position 44, which can be glutamine or threonine, and the other is at position 309, which can be tyrosine or histidine. Northern-blot analysis indicated that the mRNA for C4b-binding protein is approx. 2.5 kilobases long. The N-terminal 491 amino acids of C4b-binding protein can be divided into eight internal homologous regions, each approx. 60 amino acids long, which can be aligned by the presence in each region of four half-cystine, one tryptophan and several other conserved residues. These regions in C4b-binding protein are homologous with the three internal-homology regions that have been reported to be present within the Ba region of the complement enzyme factor B and also to the internal-homology regions found in the non-complement beta 2-glycoprotein I.

scholarly journals Self-assembling of Chimeric Mussel-inspired Bio-adhesives Originated from Mytilus Californianus and Anabaena Flos-aquae: A New Approach to Develop Underwater Adhesion

2021 ◽  
Author(s):  
Hamidreza Iranpour ◽  
Hossein Shahsavarani ◽  
Seyed Nezamedin Hosseini ◽  
Hani Hosseini Far ◽  
Sareh Zhand ◽  
...  
Keyword(s):  
Adhesion Force ◽  
Protein A ◽  
Mytilus Californianus ◽  
Chimeric Proteins ◽  
Adhesion Forces ◽  
New Approach ◽  
Underwater Adhesion ◽  
Ph Values ◽  
Self Assembling ◽  
Wide Range

Abstract Bio-adhesives play a pivotal role in a wide range of medical applications. However, there are some problems about their application in varied pH values and low adhesion force under wet conditions. Here, we report new recombinant fusion protein achieved by mussel foot proteins (Mfps) of Mytilus Californianus and gas vesicle protein A (GvpA) of Anabaena flos-aquae by genetic engineering methods. These chimeric proteins self-assembled into ß-sheet rich fibres because of GvpA amyloid structure. Also, their adhesion forces were significantly increased especially in alkaline environment based on Mfp-3 and Mfp-5. This study illustrates that copolymer of Mfp-5-GvpA:GvpA-Mfp-3 can be used as an underwater sturdy adhesive with tolerance to auto-oxidation, especially at basic conditions.

scholarly journals Construction of immunoglobulin-binding peptides based on analysis of the protein A of Staphylococcus aureus interaction with immunoglobulins Fc fragment

2019 ◽  
Vol 55 (4) ◽  
pp. 447-454
Author(s):  
A. V. Lapko ◽  
E. S. Pustyul’ga ◽  
V. P. Golubovich
Keyword(s):  
Staphylococcus Aureus ◽  
Molecular Docking ◽  
Amino Acid ◽  
Protein A ◽  
New Drugs ◽  
Amino Acid Residues ◽  
Fc Fragment ◽  
Peptide Analog ◽  
Identify Amino Acid ◽  
Starting Point

Over the past decades, molecular docking has become an increasingly popular tool for the development of new drugs. To search and design new compounds, a detailed study of the interaction of existing complexes of ligands with the target protein is necessary. According to the purpose to identify amino acid residues of the B domain of protein A of Staphylococcus aureus involved in interaction with immunoglobulins G, we studied the interaction mechanisms during the formation of a complex of protein A of the Staphylococcus aureus cell wall and immunoglobulins G by molecular docking. By the means of molecular docking we selected four amino acid residues of Phe132, Gln129, Tyr133 and Phe124, which we can use to construct a peptide analog of the active binding site of protein A with the Fc fragment of immunoglobulins G. The obtained results can serve as starting point for an effective strategy for finding new medicines, in particular, they can be used to further develop biospecific sorbent for the selective removal of immunoglobulins G from human blood.

Sign in / Sign up

Export Citation Format

Share Document