scholarly journals Modulation of Toxin-Antitoxin System Rnl AB Type II in Phage-Resistant Gammaproteobacteria Surviving Photodynamic Treatment

2018 ◽  
Vol 10 (1) ◽  
pp. 21-28
Author(s):  
Nava Hosseini ◽  
Maryam Pourhajibagher ◽  
Nasim Chiniforush ◽  
Nazanin Hosseinkhan ◽  
Parizad Rezaie ◽  
...  

Type II toxin-antitoxin (TA) systems are the particular type of TA modules which take part in different kinds of cellular actions, such as biofilm formation, persistence, stress endurance, defense of the bacterial cell against multiple phage attacks, plasmid maintenance, and programmed cell death in favor of bacterial population. Although several bioinformatics and Pet lab studies have already been conducted to understand the functionality of already discovered TA systems, still, more work in this area is required. Rnl AB type II TA module, which is composed of RnlA toxin and RnlB antitoxin, is a newly discovered type II TA module which takes part in the defense mechanism against T4 bacteriophage attack in Escherichia coli K-12 strain MH1 that has not been widely studied in other bacteria. Because of the significant role of class Gammaproteobacteriacea in a diverse range of health problems, we chose here to focus on this class to survey the presence of the Rnl AB TA module. For better categorization and description of the distribution of this module in this class of bacteria, the corresponding phylogenetic trees are illustrated here. Neighbor-joining and the maximum parsimony methods were used in this study to take a look at the distribution of domains present in RnlA and RnlB proteins, among members of Gammaproteobacteria. Also, the possible roles of photodynamic therapy (PDT) in providing a substrate for better phage therapy are herein discussed.

2022 ◽  
Vol 13 (1) ◽  
Author(s):  
Shan Wang ◽  
William D. G. Brittain ◽  
Qian Zhang ◽  
Zhou Lu ◽  
Ming Him Tong ◽  
...  

AbstractNon-Ribosomal Peptide Synthetases (NRPSs) assemble a diverse range of natural products with important applications in both medicine and agriculture. They consist of several multienzyme subunits that must interact with each other in a highly controlled manner to facilitate efficient chain transfer, thus ensuring biosynthetic fidelity. Several mechanisms for chain transfer are known for NRPSs, promoting structural diversity. Herein, we report the first biochemically characterized example of a type II thioesterase (TEII) domain capable of catalysing aminoacyl chain transfer between thiolation (T) domains on two separate NRPS subunits responsible for installation of a dehydrobutyrine moiety. Biochemical dissection of this process reveals the central role of the TEII-catalysed chain translocation event and expands the enzymatic scope of TEII domains beyond canonical (amino)acyl chain hydrolysis. The apparent co-evolution of the TEII domain with the NRPS subunits highlights a unique feature of this enzymatic cassette, which will undoubtedly find utility in biosynthetic engineering efforts.


Diabetes ◽  
1987 ◽  
Vol 36 (3) ◽  
pp. 274-283 ◽  
Author(s):  
A. D. Baron ◽  
L. Schaeffer ◽  
P. Shragg ◽  
O. G. Kolterman

Diabetes ◽  
1987 ◽  
Vol 36 (11) ◽  
pp. 1341-1350 ◽  
Author(s):  
J. P. Felber ◽  
E. Ferrannini ◽  
A. Golay ◽  
H. U. Meyer ◽  
D. Theibaud ◽  
...  

2019 ◽  
Author(s):  
Christopher Michael Kavanagh ◽  
Susilo Wibisono ◽  
Rohan Kapitány ◽  
Whinda Yustisia ◽  
Idhamsyah Eka Putra ◽  
...  

Indonesia is the most populous Islamic country and as such is host to a diverse range of Islamic beliefs and practices. Here we examine how the diversity of beliefs and practices among Indonesian Muslims relates to group bonding and parochialism. In particular, we examine the predictive power of two distinct types of group alignment, group identification and identity fusion, among individuals from three Sunni politico-religious groups - a fundamentalist group (PKS), a moderate group (NU), and a control sample of politically unaffiliated citizens. Fundamentalists were more fused to targets than moderates or citizens, but contrary to fusion theory, we found across all groups, that group identification (not fusion) better predicted parochialism, including willingness to carry out extreme pro-group actions. We discuss how religious beliefs and practice impact parochial attitudes, as well as the implications for theoretical models linking fusion to extreme behaviour.


1956 ◽  
Vol 184 (2) ◽  
pp. 296-300 ◽  
Author(s):  
László Kátó ◽  
Béla Gözsy

Experiments are presented to the effect that in an inflammatory process histamine and leucotaxin appear successively at different and orderly time intervals, thus assuring an increased fluid flow through the capillary wall. Histamine is released not only in the inflammatory process but also by intradermal administration of such substances (volatile oils or their components) which induce neither the triple response of Th. Lewis nor any tissue damage. This could be explained by the fact that in the tissues histamine is ‘present’ but leucotaxin is ‘formed.’


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
S. Duboux ◽  
M. Golliard ◽  
J. A. Muller ◽  
G. Bergonzelli ◽  
C. J. Bolten ◽  
...  

AbstractThe Serine Protease Inhibitor (serpin) protein has been suggested to play a key role in the interaction of bifidobacteria with the host. By inhibiting intestinal serine proteases, it might allow bifidobacteria to reside in specific gut niches. In inflammatory diseases where serine proteases contribute to the innate defense mechanism of the host, serpin may dampen the damaging effects of inflammation. In view of the beneficial roles of this protein, it is important to understand how its production is regulated. Here we demonstrate that Bifidobacterium longum NCC 2705 serpin production is tightly regulated by carbohydrates. Galactose and fructose increase the production of this protein while glucose prevents it, suggesting the involvement of catabolite repression. We identified that di- and oligosaccharides containing galactose (GOS) and fructose (FOS) moieties, including the human milk oligosaccharide Lacto-N-tetraose (LNT), are able to activate serpin production. Moreover, we show that the carbohydrate mediated regulation is conserved within B. longum subsp. longum strains but not in other bifidobacterial taxons harboring the serpin coding gene, highlighting that the serpin regulation circuits are not only species- but also subspecies- specific. Our work demonstrates that environmental conditions can modulate expression of an important effector molecule of B. longum, having potential important implications for probiotic manufacturing and supporting the postulated role of serpin in the ability of bifidobacteria to colonize the intestinal tract.


Author(s):  
Saied Froghi ◽  
Charlotte R. Grant ◽  
Radhika Tandon ◽  
Alberto Quaglia ◽  
Brian Davidson ◽  
...  

AbstractCalcium is the most abundant mineral in the human body and is central to many physiological processes, including immune system activation and maintenance. Studies continue to reveal the intricacies of calcium signalling within the immune system. Perhaps the most well-understood mechanism of calcium influx into cells is store-operated calcium entry (SOCE), which occurs via calcium release-activated channels (CRACs). SOCE is central to the activation of immune system cells; however, more recent studies have demonstrated the crucial role of other calcium channels, including transient receptor potential (TRP) channels. In this review, we describe the expression and function of TRP channels within the immune system and outline associations with murine models of disease and human conditions. Therefore, highlighting the importance of TRP channels in disease and reviewing potential. The TRP channel family is significant, and its members have a continually growing number of cellular processes. Within the immune system, TRP channels are involved in a diverse range of functions including T and B cell receptor signalling and activation, antigen presentation by dendritic cells, neutrophil and macrophage bactericidal activity, and mast cell degranulation. Not surprisingly, these channels have been linked to many pathological conditions such as inflammatory bowel disease, chronic fatigue syndrome and myalgic encephalomyelitis, atherosclerosis, hypertension and atopy.


Cells ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1641
Author(s):  
Emily E. S. Brettschneider ◽  
Masaki Terabe

Glioblastoma is an aggressive and deadly cancer, but to date, immunotherapies have failed to make significant strides in improving prognoses for glioblastoma patients. One of the current challenges to developing immunological interventions for glioblastoma is our incomplete understanding of the numerous immunoregulatory mechanisms at play in the glioblastoma tumor microenvironment. We propose that Natural Killer T (NKT) cells, which are unconventional T lymphocytes that recognize lipid antigens presented by CD1d molecules, may play a key immunoregulatory role in glioblastoma. For example, evidence suggests that the activation of type I NKT cells can facilitate anti-glioblastoma immune responses. On the other hand, type II NKT cells are known to play an immunosuppressive role in other cancers, as well as to cross-regulate type I NKT cell activity, although their specific role in glioblastoma remains largely unclear. This review provides a summary of our current understanding of NKT cells in the immunoregulation of glioblastoma as well as highlights the involvement of NKT cells in other cancers and central nervous system diseases.


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