Delineating a New Class of Membrane-Bound Guanylate Cyclases

2016 ◽  
Vol 4 (1) ◽  
pp. 1-13 ◽  
Author(s):  
Victor Muleya ◽  
Helen R. Irving
Keyword(s):  
New Class ◽  
Membrane Bound

scholarly journals Genetic and Phenotypic Analyses of therdx Locus of Rhodobacter sphaeroides2.4.1

2000 ◽  
Vol 182 (12) ◽  
pp. 3475-3481 ◽  
Author(s):  
Jung Hyeob Roh ◽  
Samuel Kaplan
Keyword(s):  
Gene Expression ◽  
Rhodobacter Sphaeroides ◽  
Redox Protein ◽  
Deletion Mutations ◽  
Metal Transporter ◽  
New Class ◽  
Mutant Strains ◽  
Membrane Bound ◽  
Photosynthesis Gene

ABSTRACT Previously, we reported that rdxB, encoding a likely membrane-bound two [4Fe-4S]-containing center, is involved in the aerobic regulation of photosystem gene expression in Rhodobacter sphaeroides 2.4.1. To further investigate the role ofrdxB as well as other genes of the rdxBHISoperon on photosystem gene expression, we constructed a series of nonpolar, in-frame deletion mutations in each of the rdxgenes. Using both puc and puf operonlacZ fusions to monitor photosystem gene expression, under aerobic conditions, in each of the mutant strains revealed significant increased photosynthesis gene expression. In the case of mutations in either rdxH, rdxI, or rdxS, the aerobic induction of photosystem gene expression is believed to be indirect by virtue of a posttranscriptional effect oncbb 3 cytochrome oxidase structure and integrity. For RdxB, we suggest that this redox protein has a more direct effect on photosystem gene expression by virtue of its interaction with the cbb 3 oxidase. An associated phenotype, involving the enhanced conversion of the carotenoid spheroidene to spheroidenone, is also observed in the RdxB, -H, -I, and -S mutant strains. This phenotype is also suggested to be the result of the role of the rdxBHIS locus incbb 3 oxidase activity and/or structure. RdxI is suggested to be a new class of metal transporter of the CPx-type ATPases.

scholarly journals Ceapins are a new class of unfolded protein response inhibitors, selectively targeting the ATF6α branch

eLife ◽  
2016 ◽  
Vol 5 ◽  
Author(s):  
Ciara M Gallagher ◽  
Carolina Garri ◽  
Erica L Cain ◽  
Kenny Kean-Hooi Ang ◽  
Christopher G Wilson ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Er Stress ◽  
Unfolded Protein Response ◽  
Proteolytic Processing ◽  
Unfolded Protein ◽  
New Class ◽  
Cancer Models ◽  
Membrane Bound ◽  
The Unfolded Protein Response ◽  
Protein Response

The membrane-bound transcription factor ATF6α plays a cytoprotective role in the unfolded protein response (UPR), required for cells to survive ER stress. Activation of ATF6α promotes cell survival in cancer models. We used cell-based screens to discover and develop Ceapins, a class of pyrazole amides, that block ATF6α signaling in response to ER stress. Ceapins sensitize cells to ER stress without impacting viability of unstressed cells. Ceapins are highly specific inhibitors of ATF6α signaling, not affecting signaling through the other branches of the UPR, or proteolytic processing of its close homolog ATF6β or SREBP (a cholesterol-regulated transcription factor), both activated by the same proteases. Ceapins are first-in-class inhibitors that can be used to explore both the mechanism of activation of ATF6α and its role in pathological settings. The discovery of Ceapins now enables pharmacological modulation all three UPR branches either singly or in combination.

Plant protoplast agglutination and membrane-bound beta-lectins

1977 ◽  
Vol 26 (1) ◽  
pp. 31-46
Author(s):  
P.J. Larkin
Keyword(s):  
Immune Serum ◽  
Plant Protoplast ◽  
Carbohydrate Antigens ◽  
New Class ◽  
Specific Serum ◽  
Serum Component ◽  
Membrane Bound

Plant protoplast agglutination caused by normal and immune serum and by artificial carbohydrate antigens is described. Evidence is presented that the new class of lectins, called all-beta lectins by previous authors, are present in protoplast membranes and responsible for both forms of agglutination. Some non-specific serum component and the artificial antigens are the 2 respective passive ‘bridge’ molecules between agglutinating protoplasts.

scholarly journals Controlling compartmentalization by non-membrane-bound organelles

2018 ◽  
Vol 373 (1747) ◽  
pp. 20170193 ◽  
Author(s):  
Richard J. Wheeler ◽  
Anthony A. Hyman
Keyword(s):  
Phase Separation ◽  
Cell Biology ◽  
Scaffold Protein ◽  
Theme Issue ◽  
New Class ◽  
Cellular Events ◽  
Condensate Formation ◽  
Membrane Bound ◽  
Two Phases ◽  
In Cells

Compartmentalization is a characterizing feature of complexity in cells, used to organize their biochemistry. Membrane-bound organelles are most widely known, but non-membrane-bound liquid organelles also exist. These have recently been shown to form by phase separation of specific types of proteins known as scaffolds. This forms two phases: a condensate that is enriched in scaffold protein separated by a phase boundary from the cytoplasm or nucleoplasm with a low concentration of the scaffold protein. Phase separation is well known for synthetic polymers, but also appears important in cells. Here, we review the properties of proteins important for forming these non-membrane-bound organelles, focusing on the energetically favourable interactions that drive condensation. On this basis we make qualitative predictions about how cells may control compartmentalization by condensates; the partition of specific molecules to a condensate; the control of condensation and dissolution of condensates; and the regulation of condensate nucleation. There are emerging data supporting many of these predictions, although future results may prove incorrect. It appears that many molecules may have the ability to modulate condensate formation, making condensates a potential target for future therapeutics. The emerging properties of condensates are fundamentally unlike the properties of membrane-bound organelles. They have the capacity to rapidly integrate cellular events and act as a new class of sensors for internal and external environments. This article is part of the theme issue ‘Self-organization in cell biology’.

scholarly journals Synthesis of Pyrazolo[1,2-b]phthalazine-5,10- dione Derivatives: A New Class of α –Glucosidase Inhibitors

2021 ◽  
Author(s):  
Maryam Hosseinpoor Tehrani ◽  
Seyed Ahmad Mirshokraie ◽  
Mehdi Khoobi ◽  
Mohsen Amini
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Enzyme Activity ◽  
Biological Activity ◽  
Inhibitory Activity ◽  
Diabetic Patients ◽  
New Class ◽  
Glucosidase Inhibitors ◽  
Membrane Bound ◽  
Carbohydrate Digestion ◽  
Control Post

Background: Hyperglycemia is a metabolic disorder that refers to an increase in blood sugar in diabetic patients. α-Glucosidase has been introduced as a membrane-bound enzyme, and it is the main enzyme for carbohydrate digestion in some parts of the intestine. Inhibition of α -glucosidase enzyme activity is a reliable approach to control post-prandial hyperglycemia condition. Objectives: In this study, a series of Pyrazolo[1,2-b]phthalazine-5,10-dione derivatives 5a–t were synthesized via a multicomponent reaction and evaluated as new inhibitors for α-glucosidase. Methods: The biological activity of the synthesized compounds was studied using a source of the α-glucosidase enzyme (EC3.2.1.20, Saccharomyces cerevisiae) at 20 U/mg concentration. Results: Four compounds showed higher α-glucosidase inhibitory activity in comparison to a standard, i.e., Acarbose. Compound 5q displays the most potent α-glucosidase inhibitory activity (IC50 = 155.4 ± 6.0 μM). Conclusion: In conclusion, some of the synthesized compounds, including heterocyclic core molecules, have shown remarkable activity that could be considered as subjects for the development of new, more efficient inhibitors of the α-glucosidase enzyme.

scholarly journals Non-detergent sulphobetaines: a new class of mild solubilization agents for protein purification

1995 ◽  
Vol 305 (1) ◽  
pp. 337-343 ◽  
Author(s):  
L Vuillard ◽  
C Braun-Breton ◽  
T Rabilloud
Keyword(s):  
Alkaline Phosphatase ◽  
Plasmodium Falciparum ◽  
Protein Purification ◽  
Isoelectric Focusing ◽  
Nuclear Proteins ◽  
New Class ◽  
Erythrocyte Invasion ◽  
Membrane Bound ◽  
Beta Galactosidase ◽  
Mild Solubilization

The action of non-detergent sulphobetaines (NDSBs) as new mild agents for protein purification is described. The solubilization effects of non-detergent sulphobetaines are shown in different examples; all obtained under non-denaturing conditions: (1) microsomal proteins extraction; (2) recovery after dialysis of nuclear proteins; (3) reduction of precipitation in isoelectric focusing experiments under non-denaturing conditions; and (4) purification of a membrane-bound serine protease from Plasmodium falciparum involved in erythrocyte invasion by malaria merozoites. The absence of a significant denaturation effect induced by NDSBs is demonstrated by tests on beta-galactosidase and alkaline phosphatase. A simple NDSB synthesis and some possible explanations of the action of NDSBs are also presented.

Calcium antagonistic drugs. Mechanism of action

1980 ◽  
Vol 58 (3) ◽  
pp. 254-264 ◽  
Author(s):  
Jon Church ◽  
Thomas T. Zsotér
Keyword(s):  
Mechanism Of Action ◽  
Calcium Antagonists ◽  
Selective Inhibition ◽  
New Class ◽  
Drug Concentrations ◽  
Short Period ◽  
Ca Uptake ◽  
Isolated Atria ◽  
Membrane Bound ◽  
Intracellular Action

Calcium antagonists represent a new class of drugs, which were suggested to act by a selective inhibition of Ca2+ influx through cell membranes. We studied the mechanism of action of three calcium antagonists, diltiazem, nifedipine, and verapamil, by investigating the effect on 45Ca uptake and efflux in rat heart and aorta and in rabbit vessels. The upake of La3+-resistant 45Ca was not decreased by nifedipine or verapamil either in the heart or in the vessels and was increased by diltiazem in rabbit vessels. The efflux of 45Ca from the mesenteric vein of rabbit, originating presumably from intracellular and membrane-bound fractions, was enhanced by nifedipine. These effects were observed with drug concentrations inhibiting contractions in isolated atria and the spontaneous and norepinephrine-, potassium-, or barium-induced contractions in the portal vein of rats. Thus, our results suggest that calcium antagonistic drugs act by other mechanisms than the inhibition of transmembranous Ca flux, probably on the release and binding of Ca2+ in intracellular pools. The relatively greater inhibition of norepinephrine- than K+-induced contractions in vessels by the calcium antagonistic drugs and the abolition of the inotropic effect of norepinephrine in rat atrium exposed to 0-Ca Krebs solution for a short period are other effects suggesting an intracellular action for these drugs.

A new class of membrane-bound chemokine with a CX3C motif

Nature ◽  
1997 ◽  
Vol 385 (6617) ◽  
pp. 640-644 ◽  
Author(s):  
J. Fernando Bazan ◽  
Kevin B. Bacon ◽  
Gary Hardiman ◽  
Wei Wang ◽  
Ken Soo ◽  
...  
Keyword(s):  
New Class ◽  
Membrane Bound
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