scholarly journals Inheritance of seedlessness and the molecular characterization of the INO gene in Annonaceae

2023 ◽  
Vol 83 ◽  
Author(s):  
B. R. R. M. Nassau ◽  
P. S. C. Mascarenhas ◽  
A. G. Guimarães ◽  
F. M. Feitosa ◽  
H. M. Ferreira ◽  
...  
Keyword(s):  
Sequence Similarity ◽  
Type A ◽  
Molecular Techniques ◽  
Wild Type ◽  
Annona Squamosa ◽  
High Sequence Similarity ◽  
Breeding Programs ◽  
Complete Dominance ◽  
Young Leaves

Abstract The inheritance of the seedless fruit characteristic of Annona squamosa has not yet been explained. Molecular techniques may aid breeding programs, mainly in the assisted selection of the target gene. The INO gene may be related to seed development in these fruits. The objective of the present paper was to investigate the inheritance of seedlessness in the 'Brazilian seedless' sugar apple and INO gene conservation in Annona squamosa and Annona cherimola x Annona squamosa genotypes by assessing their homology with the INO database genes. The F1 generation was obtained by crossing the mutant 'Brazilian seedless' (male genitor) (P1) with the wild-type A. squamosa with seeds (M1 and M2, female genitors). The INO gene was studied in mutant and wild-type A. squamosa (P1, M1, M2 and M3) and in the Gefner atemoya (A. cherimola x A. squamosa) (M4) cultivar. The DNA was extracted from young leaves, and four sets of specific primers flanking the INO gene were amplified. The seedless characteristic was identified as stenospermatic in the fruits of parental P1, suggesting monogenic inheritance with complete dominance. High sequence similarity of the INO gene amplifications in the sugar apple accessions (M1, M2, M3) and the atemoya cultivar Gefner (M4) reinforces the hypothesis of their conservation.

scholarly journals Cloning and Characterization of theFlavobacterium johnsoniae Gliding Motility GenesgldD and gldE

2001 ◽  
Vol 183 (14) ◽  
pp. 4167-4175 ◽  
Author(s):  
David W. Hunnicutt ◽  
Mark J. McBride
Keyword(s):  
Membrane Protein ◽  
Cytoplasmic Membrane ◽  
Sequence Similarity ◽  
Gliding Motility ◽  
Wild Type ◽  
Bacteriophage Infection ◽  
Flavobacterium Johnsoniae ◽  
Latex Spheres ◽  
Serovar Typhimurium

ABSTRACT Cells of Flavobacterium johnsoniae move over surfaces by a process known as gliding motility. The mechanism of this form of motility is not known. Cells of F. johnsoniaepropel latex spheres along their surfaces, which is thought to be a manifestation of the motility machinery. Three of the genes that are required for F. johnsoniae gliding motility,gldA, gldB, and ftsX, have recently been described. Tn4351 mutagenesis was used to identify another gene, gldD, that is needed for gliding. Tn4351-induced gldD mutants formed nonspreading colonies, and cells failed to glide. They also lacked the ability to propel latex spheres and were resistant to bacteriophages that infect wild-type cells. Introduction of wild-type gldD into the mutants restored motility, ability to propel latex spheres, and sensitivity to bacteriophage infection. gldD codes for a cytoplasmic membrane protein that does not exhibit strong sequence similarity to proteins of known function. gldE, which lies immediately upstream ofgldD, encodes another cytoplasmic membrane protein that may be involved in gliding motility. Overexpression ofgldE partially suppressed the motility defects of agldB point mutant, suggesting that GldB and GldE may interact. GldE exhibits sequence similarity to Borrelia burgdorferi TlyC and Salmonella enterica serovar Typhimurium CorC.

scholarly journals Tuning the ion selectivity of two-pore channels

2017 ◽  
Vol 114 (5) ◽  
pp. 1009-1014 ◽  
Author(s):  
Jiangtao Guo ◽  
Weizhong Zeng ◽  
Youxing Jiang
Keyword(s):  
Sequence Similarity ◽  
Ion Selectivity ◽  
Structural Basis ◽  
Monovalent Cations ◽  
Nonselective Cation Channel ◽  
High Sequence Similarity ◽  
Selective Channel ◽  
Tm Domain ◽  
Key Residues

Organellar two-pore channels (TPCs) contain two copies of aShaker-like six-transmembrane (6-TM) domain in each subunit and are ubiquitously expressed in plants and animals. Interestingly, plant and animal TPCs share high sequence similarity in the filter region, yet exhibit drastically different ion selectivity. Plant TPC1 functions as a nonselective cation channel on the vacuole membrane, whereas mammalian TPC channels have been shown to be endo/lysosomal Na+-selective or Ca2+-release channels. In this study, we performed systematic characterization of the ion selectivity of TPC1 fromArabidopsis thaliana(AtTPC1) and compared its selectivity with the selectivity of human TPC2 (HsTPC2). We demonstrate that AtTPC1 is selective for Ca2+over Na+, but nonselective among monovalent cations (Li+, Na+, and K+). Our results also confirm that HsTPC2 is a Na+-selective channel activated by phosphatidylinositol 3,5-bisphosphate. Guided by our recent structure of AtTPC1, we converted AtTPC1 to a Na+-selective channel by mimicking the selectivity filter of HsTPC2 and identified key residues in the TPC filters that differentiate the selectivity between AtTPC1 and HsTPC2. Furthermore, the structure of the Na+-selective AtTPC1 mutant elucidates the structural basis for Na+selectivity in mammalian TPCs.

scholarly journals Identification and Functional Characterization of the Novel Edwardsiella tarda Effector EseJ

2015 ◽  
Vol 83 (4) ◽  
pp. 1650-1660 ◽  
Author(s):  
Hai-Xia Xie ◽  
Jin-Fang Lu ◽  
Ying Zhou ◽  
Jia Yi ◽  
Xiu-Jun Yu ◽  
...  
Keyword(s):  
Mutant Strain ◽  
Bacterial Adhesion ◽  
Sequence Similarity ◽  
Functional Characterization ◽  
Lethal Dose ◽  
Edwardsiella Tarda ◽  
Bacterial Cells ◽  
Wild Type ◽  
High Sequence Similarity ◽  
Content Type

Edwardsiella tardais a Gram-negative enteric pathogen that causes hemorrhagic septicemia in fish and gastro- and extraintestinal infections in humans. The type III secretion system (T3SS) ofE. tardahas been identified as a key virulence factor that contributes to pathogenesis in fish. However, little is known about the associated effectors translocated by this T3SS. In this study, by comparing the profile of secreted proteins of the wild-type PPD130/91 and its T3SS ATPase ΔesaNmutant, we identified a new effector by matrix-assisted laser desorption ionization–time of flight (MALDI-TOF) mass spectrometry. This effector consists of 1,359 amino acids, sharing high sequence similarity with Orf29/30 ofE. tardastrain EIB202, and is renamed EseJ. The secretion and translocation of EseJ depend on the T3SS. A ΔeseJmutant strain adheres to epithelioma papillosum of carp (EPC) cells 3 to 5 times more extensively than the wild-type strain does. EseJ inhibits bacterial adhesion to EPC cells from within bacterial cells. Importantly, the ΔeseJmutant strain does not replicate efficiently in EPC cells and fails to replicate in J774A.1 macrophages. In infected J774A.1 macrophages, the ΔeseJmutant elicits higher production of reactive oxygen species than wild-typeE. tarda. The replication defect is consistent with the attenuation of the ΔeseJmutant in the blue gourami fish model: the 50% lethal dose (LD50) of the ΔeseJmutant is 2.34 times greater than that of the wild type, and the ΔeseJmutant is less competitive than the wild type in mixed infection. Thus, EseJ represents a novel effector that contributes to virulence by reducing bacterial adhesion to EPC cells and facilitating intracellular bacterial replication.

scholarly journals Characterization of an ADP-Ribosyltransferase Toxin (AexT) from Aeromonas salmonicida subsp. salmonicida

2002 ◽  
Vol 184 (7) ◽  
pp. 1851-1858 ◽  
Author(s):  
Martin Braun ◽  
Katja Stuber ◽  
Yvonne Schlatter ◽  
Thomas Wahli ◽  
Peter Kuhnert ◽  
...  
Keyword(s):  
Culture Medium ◽  
Morphological Changes ◽  
Polyclonal Antibodies ◽  
Sequence Similarity ◽  
Aeromonas Salmonicida ◽  
Wild Type ◽  
Significant Sequence Similarity ◽  
Fish Cells ◽  
Adp Ribosyltransferase

ABSTRACT An ADP-ribosylating toxin named Aeromonas salmonicida exoenzyme T (AexT) in A. salmonicida subsp. salmonicida, the etiological agent of furunculosis in fish, was characterized. Gene aexT, encoding toxin AexT, was cloned and characterized by sequence analysis. AexT shows significant sequence similarity to the ExoS and ExoT exotoxins of Pseudomonas aeruginosa and to the YopE cytotoxin of different Yersinia species. The aexT gene was detected in all of the 12 A. salmonicida subsp. salmonicida strains tested but was absent from all other Aeromonas species. Recombinant AexT produced in Escherichia coli possesses enzymatic ADP-ribosyltransferase activity. Monospecific polyclonal antibodies directed against purified recombinant AexT detected the toxin produced by A. salmonicida subsp. salmonicida and cross-reacted with ExoS and ExoT of P. aeruginosa. AexT toxin could be detected in a wild type (wt) strain of A. salmonicida subsp. salmonicida freshly isolated from a fish with furunculosis; however, its expression required contact with RTG-2 rainbow trout gonad cells. Under these conditions, the AexT protein was found to be intracellular or tightly cell associated. No AexT was found when A. salmonicida subsp. salmonicida was incubated in cell culture medium in the absence of RTG-2 cells. Upon infection with wt A. salmonicida subsp. salmonicida, the fish gonad RTG-2 cells rapidly underwent significant morphological changes. These changes were demonstrated to constitute cell rounding, which accompanied induction of production of AexT and which led to cell lysis after extended incubation. An aexT mutant which was constructed from the wt strain with an insertionally inactivated aexT gene by allelic exchange had no toxic effect on RTG-2 cells and was devoid of AexT production. Hence AexT is directly involved in the toxicity of A. salmonicida subsp. salmonicida for RTG-2 fish cells.

scholarly journals Isolation and Characterization of Insecticidal Toxins from the Venom of the North African Scorpion, Buthacus leptochelys

Toxins ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 236 ◽  
Author(s):  
Yusuke Yoshimoto ◽  
Masahiro Miyashita ◽  
Mohammed Abdel-Wahab ◽  
Moustafa Sarhan ◽  
Yoshiaki Nakagawa ◽  
...  
Keyword(s):  
Sequence Similarity ◽  
Scorpion Venom ◽  
Spectrometric Analysis ◽  
North African ◽  
High Sequence Similarity ◽  
The North ◽  
Isolation And Characterization ◽  
Ms Analysis ◽  
Insect Toxicity

Various bioactive peptides have been identified in scorpion venom, but there are many scorpion species whose venom has not been investigated. In this study, we characterized venom components of the North African scorpion, Buthacus leptochelys, by mass spectrometric analysis and evaluated their insect toxicity. This is the first report of chemical and biological characterization of the B. leptochelys venom. LC/MS analysis detected at least 148 components in the venom. We isolated four peptides that show insect toxicity (Bl-1, Bl-2, Bl-3, and Bl-4) through bioassay-guided HPLC fractionation. These toxins were found to be similar to scorpion α- and β-toxins based on their N-terminal sequences. Among them, the complete primary structure of Bl-1 was determined by combination of Edman degradation and MS/MS analysis. Bl-1 is composed of 67 amino acid residues and crosslinked with four disulfide bonds. Since Bl-1 shares high sequence similarity with α-like toxins, it is likely that it acts on Na+ channels of both insects and mammals.

scholarly journals Isolation and structural characterization of insulin and glucagon from the holocephalan species Callorhynchus milii (elephantfish)

1989 ◽  
Vol 263 (1) ◽  
pp. 261-266 ◽  
Author(s):  
B C Berks ◽  
C J Marshall ◽  
A Carne ◽  
S M Galloway ◽  
J F Cutfield
Keyword(s):  
Gas Phase ◽  
Receptor Binding ◽  
Structural Characterization ◽  
Sequence Similarity ◽  
Cartilaginous Fish ◽  
Proteolytic Processing ◽  
Reverse Phase ◽  
High Sequence Similarity ◽  
Processing Mechanisms

Both insulin and glucagon from the pancreas of the holocephalan cartilaginous fish Callorhynchus milii (elephantfish) have been isolated and purified. Two reverse-phase h.p.l.c. steps enabled recovery of sufficient material for gas-phase sequencing of the intact chains as well as peptide digestion products. The elephantfish insulin sequence shows 14 differences from pig insulin, including two unusual substitutions, Val-A14 and Gln-B30, though none of these is thought likely to influence receptor binding significantly. The insulin B-chain contains 31 residues, one more than mammalian insulins, but markedly less than that of the closely related ratfish with which it otherwise exhibits high sequence similarity. Elephantfish and pig glucagons differ at only four positions, but there are six changes from the ratfish glucagon-36 (normal glucagon contains 29 residues) sequence. It is apparent that different prohormone proteolytic processing mechanisms operate in the two holocephalan species.

scholarly journals Enhanced Biofilm Formation and Loss of Capsule Synthesis: Deletion of a Putative Glycosyltransferase in Porphyromonas gingivalis

2006 ◽  
Vol 188 (15) ◽  
pp. 5510-5523 ◽  
Author(s):  
Mary E. Davey ◽  
Margaret J. Duncan
Keyword(s):  
Porphyromonas Gingivalis ◽  
Biofilm Formation ◽  
Capsular Polysaccharide ◽  
Sequence Similarity ◽  
Opportunistic Pathogen ◽  
Insertion Mutant ◽  
Wild Type ◽  
High Sequence Similarity ◽  
Biofilm Development

ABSTRACT Periodontitis is a biofilm-mediated disease. Porphyromonas gingivalis is an obligate anaerobe consistently associated with severe manifestations of this disease. As an opportunistic pathogen, the ability to proliferate within and disseminate from subgingival biofilm (plaque) is central to its virulence. Here, we report the isolation of a P. gingivalis transposon insertion mutant altered in biofilm development and the reconstruction and characterization of this mutation in three different wild-type strains. The mutation responsible for the altered biofilm phenotype was in a gene with high sequence similarity (∼61%) to a glycosyltransferase gene. The gene is located in a region of the chromosome that includes up to 16 genes predicted to be involved in the synthesis and transport of capsular polysaccharide. The phenotype of the reconstructed mutation in all three wild-type backgrounds is that of enhanced biofilm formation. In addition, in strain W83, a strain that is encapsulated, the glycosyltransferase mutation resulted in a loss of capsule. Further experiments showed that the W83 mutant strain was more hydrophobic and exhibited increased autoaggregation. Our results indicate that we have identified a gene involved in capsular-polysaccharide synthesis in P. gingivalis and that the production of capsule prevented attachment and the initiation of in vitro biofilm formation on polystyrene microtiter plates.

scholarly journals Molecular Analysis of CPRα, a MATα-Specific Pheromone Receptor Gene of Cryptococcus neoformans

2002 ◽  
Vol 1 (3) ◽  
pp. 432-439 ◽  
Author(s):  
Seyung Chung ◽  
Marvin Karos ◽  
Yun C. Chang ◽  
Jan Lukszo ◽  
Brian L. Wickes ◽  
...  
Keyword(s):  
Cryptococcus Neoformans ◽  
G Protein ◽  
Sequence Similarity ◽  
Receptor Gene ◽  
Environmental Cues ◽  
Wild Type ◽  
High Sequence Similarity ◽  
Pheromone Receptor ◽  
Mating Efficiency ◽  
G Protein Coupled

ABSTRACT The putative Cryptococcus neoformans pheromone receptor gene CPRα was isolated and studied for its role in mating and filamentation. CPRα is MATα specific and located adjacent to STE12α at the MATα locus. It encodes a protein which possesses high sequence similarity to the seven-transmembrane class of G-protein-coupled pheromone receptors reported for other basidiomycetous fungi. Strains containing a deletion of the CPRα gene exhibited drastic reductions in mating efficiency but were not completely sterile. Δcprα cells displayed wild-type mating efficiency when reconstituted with the wild-type CPRα gene. Hyphal production on filament agar was not affected in the Δcprα strain, indicating no significant role for CPRα in sensing environmental cues during haploid fruiting. The wild-type MATα CPRα strain produced abundant hyphae in response to synthetic MATa pheromone; however, the hyphal response to pheromone by Δcprα cells was significantly reduced. Exposure of wild-type cells to synthetic MATa pheromone for 2 h induced MFα pheromone expression, whereas unexposed cells showed only basal levels of the MFα transcript. The Δcprα cells, however, exhibited only basal levels of MFα message with or without pheromone exposure, suggesting that CPRα and MFα are components of the same signaling pathway.

scholarly journals The Hansenula polymorpha PER1 gene is essential for peroxisome biogenesis and encodes a peroxisomal matrix protein with both carboxy- and amino-terminal targeting signals.

1994 ◽  
Vol 127 (3) ◽  
pp. 737-749 ◽  
Author(s):  
H R Waterham ◽  
V I Titorenko ◽  
P Haima ◽  
J M Cregg ◽  
W Harder ◽  
...  
Keyword(s):  
Matrix Protein ◽  
Sequence Similarity ◽  
Hansenula Polymorpha ◽  
Matrix Proteins ◽  
Regulatory Function ◽  
Wild Type ◽  
Amino Terminal ◽  
Peroxisomal Targeting ◽  
Targeting Signal

We describe the cloning of the Hansenula polymorpha PER1 gene and the characterization of the gene and its product, PER1p. The gene was cloned by functional complementation of a per1 mutant of H. polymorpha, which was impaired in the import of peroxisomal matrix proteins (Pim- phenotype). The DNA sequence of PER1 predicts that PER1p is a polypeptide of 650 amino acids with no significant sequence similarity to other known proteins. PER1 expression was low but significant in wild-type H. polymorpha growing on glucose and increased during growth on any one of a number of substrates which induce peroxisome proliferation. PER1p contains both a carboxy- (PTS1) and an amino-terminal (PTS2) peroxisomal targeting signal which both were demonstrated to be capable of directing bacterial beta-lactamase to the organelle. In wild-type H. polymorpha PER1p is a protein of low abundance which was demonstrated to be localized in the peroxisomal matrix. Our results suggest that the import of PER1p into peroxisomes is a prerequisite for the import of additional matrix proteins and we suggest a regulatory function of PER1p on peroxisomal protein support.

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