scholarly journals Anopheles gambiae TEP1 forms a complex with the coiled-coil domain of LRIM1/APL1C following a conformational change in the thioester domain

2019 ◽  
Author(s):  
Marni Williams ◽  
Alicia Contet ◽  
Elena A. Levashina ◽  
Richard H. G. Baxter
Keyword(s):  
Immune Response ◽  
Anopheles Gambiae ◽  
Conformational Change ◽  
Disulfide Bonds ◽  
Room Temperature ◽  
Coiled Coil ◽  
Sub Saharan Africa ◽  
Coiled Coil Domain ◽  
Wide Range ◽  
The Stability

AbstractThe complement-like protein thioester-containing protein 1 (TEP1) is a key factor in the immune response of the malaria vector Anopheles gambiae to pathogens. Multiple allelic variants of TEP1 have been identified in laboratory strains and in the field, and are correlated with distinct immunophenotypes. TEP1 is tightly regulated by conformational changes induced by cleavage in a protease-sensitive region. Cleaved TEP1 forms a soluble complex with a heterodimer of two leucine-rich repeat proteins, LRIM1 and APL1C, and precipitates in the absence of this complex. The molecular structure and oligomeric state of the TEP1/LRIM1/APL1C complex is unclear. We have analyzed the stability of the cleaved form of four TEP1 alleles. Soluble TEP1 forms exhibit significant variation in stability from hours to days at room temperature. Stability is correlated with allelic variation within two specific loops in direct proximity to the thioester bond. The variable loops are part of an interface between the TED and MG8 domains TEP1 that protect the thioester from hydrolysis. Engineering specific disulfide bonds to prevent separation of the TED-MG8 interface stabilizes the cleaved form of TEP1 for months at room temperature. The C-terminal coiled-coil domain of the LRIM1/APL1C complex is sufficient to stabilize the cleaved form of TEP1 in solution but cleaved forms of disulfide-stabilized TEP1 do not interact with LRIM1/APL1C. This implies that formation of the TEP1cut/LRIM1/APL1C complex is dependent on the same conformational change that induces the precipitation of cleaved TEP1.Author SummaryThe mosquito Anopheles gambiae is the principal vector for malaria in Sub-Saharan Africa. A mosquito’s own immune system affects how readily it transmits disease. A protein in A. gambiae called TEP1 is responsible for targeting malaria parasites that traverse the mosquito’s midgut. TEP1 has multiple alleles and some are associated with a stronger immune response to malaria than others. How genetic variability in TEP1 is linked to phenotypic diversity is not understood. We show that the variation between TEP1 alleles affects the stability of the protein in solution. We also show that the different TEP1 alleles have a wide range in stability of the protein, from hours to days. Engineering disulfide bonds into TEP1 can increase this stability to months. TEP1 activity in vivo is maintained by a complex of two leucine-rich proteins called LRIM1 and APL1C, which binds TEP1 through its C-terminal coiled-coil domain. We found that LRIM1/APL1C does not bind disulfide-stabilized TEP1, suggesting that LRIM1/APL1C binds to activated TEP1. This research advances our molecular understanding of a key immune response that affects the capacity of A. gambiae mosquitoes to transmit malaria.

scholarly journals Anopheles gambiae TEP1 forms a complex with the coiled-coil domain of LRIM1/APL1C following a conformational change in the thioester domain

PLoS ONE ◽  
2019 ◽  
Vol 14 (6) ◽  
pp. e0218203 ◽  
Author(s):  
Marni Williams ◽  
Alicia Contet ◽  
Chun-Feng David Hou ◽  
Elena A. Levashina ◽  
Richard H. G. Baxter
Keyword(s):  
Anopheles Gambiae ◽  
Conformational Change ◽  
Coiled Coil ◽  
Coiled Coil Domain

scholarly journals CLIPB10 is a Terminal Protease in the Regulatory Network That Controls Melanization in the African Malaria Mosquito Anopheles gambiae

2021 ◽  
Vol 10 ◽  
Author(s):  
Xin Zhang ◽  
Miao Li ◽  
Layla El Moussawi ◽  
Sally Saab ◽  
Shasha Zhang ◽  
...  
Keyword(s):  
Anopheles Gambiae ◽  
Serine Proteases ◽  
Ex Vivo ◽  
Protein A ◽  
Tumor Formation ◽  
Sub Saharan Africa ◽  
Humoral Immune ◽  
Wide Range ◽  
Sub Saharan

Humoral immune responses in animals are often tightly controlled by regulated proteolysis. This proteolysis is exerted by extracellular protease cascades, whose activation culminates in the proteolytic cleavage of key immune proteins and enzymes. A model for such immune system regulation is the melanization reaction in insects, where the activation of prophenoxidase (proPO) leads to the rapid formation of eumelanin on the surface of foreign entities such as parasites, bacteria and fungi. ProPO activation is tightly regulated by a network of so-called clip domain serine proteases, their proteolytically inactive homologs, and their serpin inhibitors. In Anopheles gambiae, the major malaria vector in sub-Saharan Africa, manipulation of this protease network affects resistance to a wide range of microorganisms, as well as host survival. However, thus far, our understanding of the molecular make-up and regulation of the protease network in mosquitoes is limited. Here, we report the function of the clip domain serine protease CLIPB10 in this network, using a combination of genetic and biochemical assays. CLIPB10 knockdown partially reversed melanotic tumor formation induced by Serpin 2 silencing in the absence of infection. CLIPB10 was also partially required for the melanization of ookinete stages of the rodent malaria parasite Plasmodium berghei in a refractory mosquito genetic background. Recombinant serpin 2 protein, a key inhibitor of the proPO activation cascade in An. gambiae, formed a SDS-stable protein complex with activated recombinant CLIPB10, and efficiently inhibited CLIPB10 activity in vitro at a stoichiometry of 1.89:1. Recombinant activated CLIPB10 increased PO activity in Manduca sexta hemolymph ex vivo, and directly activated purified M. sexta proPO in vitro. Taken together, these data identify CLIPB10 as the second protease with prophenoloxidase-activating function in An. gambiae, in addition to the previously described CLIPB9, suggesting functional redundancy in the protease network that controls melanization. In addition, our data suggest that tissue melanization and humoral melanization of parasites are at least partially mediated by the same proteases.

scholarly journals Sustainable Hydrogenation of Vinyl Derivatives Using Pd/C Catalysts

Catalysts ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 179
Author(s):  
Roman M. Mironenko ◽  
Elina R. Saybulina ◽  
Liudmila N. Stepanova ◽  
Tatiana I. Gulyaeva ◽  
Mikhail V. Trenikhin ◽  
...  
Keyword(s):  
Molecular Hydrogen ◽  
Room Temperature ◽  
Reaction Conditions ◽  
Liquid Phase Hydrogenation ◽  
Wide Range ◽  
Hydrogenation Reactions ◽  
The Stability ◽  
Vinyl Group ◽  
Vinyl Derivatives ◽  
Hydrogenation Selectivity

The hydrogenation of unsaturated double bonds with molecular hydrogen is an efficient atom-economic approach to the production of a wide range of fine chemicals. In contrast to a number of reducing reagents typically involved in organic synthesis, hydrogenation with H2 is much more sustainable since it does not produce wastes (i.e., reducing reagent residues). However, its full sustainable potential may be achieved only in the case of easily separable catalysts and high reaction selectivity. In this work, various Pd/C catalysts were used for the liquid-phase hydrogenation of O-, S-, and N-vinyl derivatives with molecular hydrogen under mild reaction conditions (room temperature, pressure of 1 MPa). Complete conversion and high hydrogenation selectivity (>99%) were achieved by adjusting the type of Pd/C catalyst. Thus, the proposed procedure can be used as a sustainable method for vinyl group transformation by hydrogenation reactions. The discovery of the stability of active vinyl functional groups conjugated with heteroatoms (O, S, and N) under hydrogenation conditions over Pd/C catalysts opens the way for many useful transformations.

scholarly journals The coiled coil domain of DEF6 facilitates formation of large vesicle-like, cytoplasmic aggregates that trap the P-body marker DCP1 and exhibit prion-like features

2019 ◽  
Author(s):  
Huaitao Cheng ◽  
Fred Sablitzky
Keyword(s):  
Conformational Change ◽  
Rho Gtpases ◽  
Immunological Synapse ◽  
Coiled Coil ◽  
Nucleotide Exchange ◽  
Ph Domain ◽  
Mutant Proteins ◽  
P Bodies ◽  
Coiled Coil Domain ◽  
Large Vesicle

ABSTRACTDEF6, also known as SLAT and IBP, is critical for the development of autoimmune disease and cancer. In T cells, DEF6 participates in TCR-mediated signalling determining T helper cell-mediated immune responses. In addition, DEF6 acts as a guanine nucleotide exchange factor for Rho GTPases facilitating F-actin assembly and stabilisation of the immunological synapse. However, DEF6 is also a component of mRNA processing bodies (P-bodies) linking it to mRNA metabolism. DEF6 can adopt multiple conformations that result in different cellular localisations and functions. Post translational modifications such as phosphorylation result in conformational change liberating functional domains that are masked in the native stage of DEF6. ITK phosphorylation of Try210/222 liberates the N-terminal end and to a certain extend also the C-terminal coiled coil domain of DEF6 resulting in P-body colocalisation. In fact, the N-terminal 45 amino acids of DEF6 that encode a Ca2+-binding EF hand are sufficient to target P-bodies. Mutant proteins that unleashed the C-terminal coiled coil domain of DEF6 spontaneously aggregated forming large vesicle-like, cytoplasmic structures. These aggregates trapped proteins such as the P-body component DCP1 altering its cytoplasmic localisation. However, cellular stress reversed aggregate formation in mutant DEF6 proteins that contained ITAM and PH domain in conjunction with the coiled coil domain resulting in colocalisation with DCP1. Furthermore, coiled coil-mediated aggregates appeared to function like prions enforcing conformational change onto wild type DEF6 protein.

scholarly journals TRIM29 in Cutaneous Squamous Cell Carcinoma

2021 ◽  
Vol 8 ◽  
Author(s):  
Che-Yuan Hsu ◽  
Teruki Yanagi ◽  
Hideyuki Ujiie
Keyword(s):  
Malignant Tumors ◽  
Coiled Coil ◽  
Dna Damage Signaling ◽  
Physiological Processes ◽  
Trim Protein ◽  
Coiled Coil Domain ◽  
Zinc Finger Motifs ◽  
Wide Range ◽  
Trim Proteins

Tripartite motif (TRIM) proteins play important roles in a wide range of cell physiological processes, such as signal transduction, transcriptional regulation, innate immunity, and programmed cell death. TRIM29 protein, encoded by the ATDC gene, belongs to the RING-less group of TRIM protein family members. It consists of four zinc finger motifs in a B-box domain and a coiled-coil domain, and makes use of the B-box domain as E3 ubiquitin ligase in place of the RING. TRIM29 was found to be involved in the formation of homodimers and heterodimers in relation to DNA binding; additional studies have also demonstrated its role in carcinogenesis, DNA damage signaling, and the suppression of radiosensitivity. Recently, we reported that TRIM29 interacts with keratins and FAM83H to regulate keratin distribution. Further, in cutaneous SCC, the expression of TRIM29 is silenced by DNA methylation, leading to the loss of TRIM29 and promotion of keratinocyte migration. This paper reviews the role of TRIM family proteins in malignant tumors, especially the role of TRIM29 in cutaneous SCC.

scholarly journals Spatial modelling for population replacement of mosquito vectors at continental scale

2021 ◽  
Author(s):  
Nicholas J. Beeton ◽  
Andrew Wilkins ◽  
Adrien Ickowicz ◽  
Keith R. Hayes ◽  
Geoffrey R. Hosack
Keyword(s):  
Anopheles Gambiae ◽  
Control Strategies ◽  
Drive System ◽  
Sub Saharan Africa ◽  
Malaria Vectors ◽  
Anopheles Coluzzii ◽  
Gene Drive ◽  
Continental Scale ◽  
Wide Range ◽  
Sub Saharan

AbstractMalaria is one of the deadliest vector-borne diseases in the world. Researchers are developing new genetic and conventional vector control strategies to attempt to limit its burden. To be deployed responsibly and successfully, proposed novel control strategies require detailed safety assessment. Anopheles gambiae sensu stricto (s.s.) and Anopheles coluzzii, two closely related subspecies within the species complex Anopheles gambiae sensu lato (s.l.), are among the dominant malaria vectors in sub-Saharan Africa. These two subspecies readily hybridise and compete in the wild and are also known to have distinct niches, each with spatially and temporally varying carrying capacities driven by precipitation and land use factors.We model the spread and persistence of a population-modifying gene drive system in these subspecies across sub-Saharan Africa, by simulating introductions of genetically modified mosquitoes across the African mainland as well as on some offshore islands. We explore transmission of the gene drive between the subspecies, different hybridisation mechanisms, the effects of both local dispersal and potential wind-aided migration to the spread, and the development of resistance to the gene drive. We find that given best current available knowledge on the subspecies’ life histories, an introduced gene drive system with typical characteristics can plausibly spread from even distant offshore islands to the African mainland with the aid of wind-driven migration, with resistance taking over within a decade. Our model demonstrates a range of realistic dynamics including the effect of prevailing wind on spread and spatio-temporally varying carrying capacities for subspecies. We thus show both the plausibility and importance of accounting for a wide range of mechanisms from regional to continental scales.

The stability of the protective antigen and histamine-sensitizing factor of Bordetella pertussis to acid and alkali

1968 ◽  
Vol 14 (2) ◽  
pp. 147-151
Author(s):  
Cvetka M. Jakus ◽  
Lyn McClure ◽  
A. C. Wardlaw
Keyword(s):  
Bordetella Pertussis ◽  
Room Temperature ◽  
Protective Antigen ◽  
Destructive Effect ◽  
Ph Values ◽  
Wide Range ◽  
Future Value ◽  
The Stability

Pertussis sonic lysates were adjusted to a series of pH values between 3.0 and 11.0, held for 1 hour at room temperature, and then returned to neutrality and assayed for residual mouse protective antigen (MPA) and histamine-sensitizing factor (HSF) activities. The percentage in-activation of MPA at pH 3.0, 10.0, and 11.0 was respectively 30, 18, and 40 but only the last value is significantly different from the pH 7.2 control. The percentage inactivation of HSF in the same samples was 40, 29, and 75 respectively. Exposure to pH 11.0 had a significantly greater destructive effect on HSF than on MPA.These data may be of future value in helping to develop methods for purifying MPA, for they indicate that this factor is reasonably stable to pH within a usefully wide range.

Contributions of the ionization states of acidic residues to the stability of the coiled coil domain of matrilin-1

FEBS Letters ◽  
1999 ◽  
Vol 446 (1) ◽  
pp. 75-80 ◽  
Author(s):  
Sonja A. Dames ◽  
Richard A. Kammerer ◽  
Detlef Moskau ◽  
Jürgen Engel ◽  
Andrei T. Alexandrescu
Keyword(s):  
Coiled Coil ◽  
Coiled Coil Domain ◽  
Acidic Residues ◽  
The Stability

scholarly journals The clear and dark sides of water: influence on the coiled coil folding domain

2016 ◽  
Vol 7 (3) ◽  
pp. 189-195 ◽  
Author(s):  
Tamás Vajda ◽  
András Perczel
Keyword(s):  
Water Molecule ◽  
Essential Role ◽  
Polypeptide Chain ◽  
Coiled Coil ◽  
Type Ii ◽  
Coiled Coil Domain ◽  
Coil Structure ◽  
Influence Of Water ◽  
The Stability

AbstractThe essential role of water in extra- and intracellular coiled coil structures of proteins is critically evaluated, and the different protein types incorporating coiled coil units are overviewed. The following subjects are discussed: i) influence of water on the formation and degradation of the coiled coil domain together with the stability of this conformer type; ii) the water’s paradox iii) design of coiled coil motifs and iv) expert opinion and outlook is presented. The clear and dark sides refer to the positive and negative aspects of the water molecule, as it may enhance or inhibit a given folding event. This duplicity can be symbolized by the Roman ‘Janus-face’ which means that water may facilitate and stimulate coiled coil structure formation, however, it may contribute to the fatal processes of oligomerization and amyloidosis of the very same polypeptide chain.

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