Natural polyamines stimulate G-proteins

Bueb, Jean-Luc; Silva, A. Da; Mousli, Marc; Landry, Yves

doi:10.1042/bj2820545

Cited by 90 publications

(56 citation statements)

References 37 publications

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“…By contrast, the second model is supported by our results, which show that pretreatment of rabbit mucosa in the Ussing chamber with cadaverine protected the mucosa from the effect(s) of enterotoxins added after the cadaverine was washed from the tissue (see Results). Polyamines such as cadaverine are absorbed from the lumen by rabbit small intestine cells (33), and it has been proposed that intracellular polyamines might act as second messengers in the eukaryotic cell by modulation of extracellular signals transduced through G protein-coupled receptors (34). In this light, cadaverine could protect the cell by closing ion channels induced by bacterial toxins, altering intracellular signaling, or displacing toxin from cellular receptors.…”

Section: Discussionmentioning

confidence: 99%

“Black holes” and bacterial pathogenicity: A large genomic deletion that enhances the virulence of Shigella spp. and enteroinvasive Escherichia coli

Maurelli

Fernández²,

Bloch³

et al. 1998

Proc. Natl. Acad. Sci. U.S.A.

408

308

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Plasmids, bacteriophages, and pathogenicity islands are genomic additions that contribute to the evolution of bacterial pathogens. For example, Shigella spp., the causative agents of bacillary dysentery, differ from the closely related commensal Escherichia coli in the presence of a plasmid in Shigella that encodes virulence functions. However, pathogenic bacteria also may lack properties that are characteristic of nonpathogens. Lysine decarboxylase (LDC) activity is present in Ϸ90% of E. coli strains but is uniformly absent in Shigella strains. When the gene for LDC, cadA, was introduced into Shigella flexneri 2a, virulence became attenuated, and enterotoxin activity was inhibited greatly. The enterotoxin inhibitor was identified as cadaverine, a product of the reaction catalyzed by LDC. Comparison of the S. flexneri 2a and laboratory E. coli K-12 genomes in the region of cadA revealed a large deletion in Shigella. Representative strains of Shigella spp. and enteroinvasive E. coli displayed similar deletions of cadA. Our results suggest that, as Shigella spp. evolved from E. coli to become pathogens, they not only acquired virulence genes on a plasmid but also shed genes via deletions. The formation of these ''black holes,'' deletions of genes that are detrimental to a pathogenic lifestyle, provides an evolutionary pathway that enables a pathogen to enhance virulence. Furthermore, the demonstration that cadaverine can inhibit enterotoxin activity may lead to more general models about toxin activity or entry into cells and suggests an avenue for antitoxin therapy. Thus, understanding the role of black holes in pathogen evolution may yield clues to new treatments of infectious diseases.

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Section: Discussionmentioning

confidence: 99%

“Black holes” and bacterial pathogenicity: A large genomic deletion that enhances the virulence of Shigella spp. and enteroinvasive Escherichia coli

Maurelli

Fernández²,

Bloch³

et al. 1998

Proc. Natl. Acad. Sci. U.S.A.

408

308

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“…Basic secretagogues induce a rapid production of IP 3 , indicating concomitant PLC activation and histamine secretion (6,8,9,14,16). The present results confirm the participation of the PLC␤ family in this process, as could be predicted from its ability to be activated by heterotrimeric G proteins (35).…”

Section: Discussionmentioning

confidence: 99%

“…Anaphylatoxin C3a, a fragment from the third component of complement, also belongs to the family of mast cell basic secretagogues (6), extending their interest in late immunological reactions. Other basic secretagogues include venom peptides such as mastoparan (4,7,8), polyamines such as spermine and compound 48/80 (9,10), and many cationic drugs currently being used therapeutically, with adverse effects related to mast cell activation (11).…”

mentioning

confidence: 99%

Activation of βγ Subunits of Gi2 and Gi3 Proteins by Basic Secretagogues Induces Exocytosis Through Phospholipase Cβ and Arachidonate Release Through Phospholipase Cγ in Mast Cells

Ferry

Eichwald

Daeffler

et al. 2001

The Journal of Immunology

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Mast cells are activated by Ag-induced clustering of IgE bound to FcεRI receptors or by basic secretagogues that stimulate pertussis toxin-sensitive heterotrimeric G proteins. The cell response includes the secretion of stored molecules, such as histamine, through exocytosis and of de novo synthesized mediators, such as arachidonate metabolites. The respective roles of G proteins α and βγ subunits as well as various types of phospholipase C (PLC) in the signaling pathways elicited by basic secretagogues remain unknown. We show that a specific Ab produced against the C-terminus of Gαi3 and an anti-recombinant Gαi2 Ab inhibited, with additive effects, both exocytosis and arachidonate release from permeabilized rat peritoneal mast cells elicited by the basic secretagogues mastoparan and spermine. A specific Ab directed against Gβγ dimers prevented both secretions. Anti-PLCβ Abs selectively prevented exocytosis. The selective phosphatidylinositol 3-kinase inhibitor LY 294002 prevented arachidonate release without modifying exocytosis. Gβγ coimmunoprecipitated with PLCβ and phosphatidylinositol 3-kinase. The anti-PLCγ1 and anti-phospholipase A2 Abs selectively blocked arachidonate release. Protein tyrosine phosphorylation was inhibited by anti-Gβγ Abs, LY294002, and anti PLCγ1 Abs. These data show that the early step of basic secretagogue transduction is common to both signaling pathways, involving βγ subunits of Gi2 and Gi3 proteins. Activated Gβγ interacts, on one hand, with PLCβ to elicit exocytosis and, on the other hand, with phosphatidylinositol 3-kinase to initiate the sequential activation of PLCγ1, tyrosine kinases, and phospholipase A2, leading to arachidonate release.

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“…In particular, some reports have focused on the putative role of polyamines in the transduction of extracellular signals. For example, it has been suggested that G proteins may represent an important intracellular target for polyamines (Koenig et al, 1983;Bueb et al, 1992) and that these polycations influence the turnover of inositolphospholipids (Dureja- Munjal et al, 1992). On the other hand, much evidence has been provided regarding polyamine binding to cytosolic proteins.…”

Section: Dlscusslonmentioning

confidence: 99%

Polyamine Binding to Plasma Membrane Vesicles Isolated from Zucchini Hypocotyls

Tassoni¹,

Antognoni²,

Bagni³

1996

Plant Physiol.

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Aliphatic polyamines are ubiquitous polycationic substances in prokaryotic and eukaryotic cells that influence a variety of cellular processes, although their mechanism of action remains to be clarified. In plants they are implicated in the regulation of developmental processes such as embryogenesis, senescence, and flowering.Because of their protonated amino and imino groups at physiological pH values, polyamines bind to anionic cell constituents such as nucleic acids, phospholipids, negatively charged protein residues of membranes, and pectic substances of cell walls. In vivo and in vitro interactions with DNA, tRNA, and rRNA are well known (Bagni et al., 1982;Igarashi et al., 1982;Feuerstein and Marton, 1989). Evidence suggests that their role is to stabilize and affect the conformation of nucleic acids and their activities, resulting in improved translation and protein synthesis (Cocucci and Bagni, 1968;Quigley et al., 1978).The interaction between polyamines and membranes is suggested to be an intermediate in many important cellular events such as membrane fusion (Schuber et al., 1983) transmission of receptor-mediated signals (Koenig et al., 1983), and regulation of prostaglandin synthesis (Igarashi et al., 1981). Nevertheless, information on interactions between polyamines and the PM is very scarce, although their ability to stabilize biological membranes has been demonstrated (Schuber, 1989). Studies in vitro have shown that polyamines can bind to artificial membranes such as liposomes and that the binding strength of the complexes depends on the type and density of acidic phospholipids present in the vesicles (Tadolini et al., 1986).In animals, specific polyamine-binding proteins have been detected in severa1 tissues and body fluids. A spermine-binding protein was found, for example, in the cytosol of duodenal mucosa of newborn chick (Mezzetti et al., 1981). This interaction can be regulated by the hormonal form of vitamin D, (Mezzetti et al., 1983).Because systematic studies have yet to be undertaken on this topic in plants, in the present work we have attempted to define the characteristics of spermidine binding to purified PM isolated from etiolated hypocotyls of zucchini (Cucurbita pepo L.).The experiments reported here represent a preliminary step toward the identification of putative polyaminebinding sites and/or carriers at the plasmalemma leve1 in plant cells. MATERIALS A N D METHODS Plant MaterialSeeds of zucchini (Cucurbita pepo L. hybrid Storr's Green, Asgrow Co., Lodi, Italy) were planted in moist vermiculite and grown at 22 ? 1°C in total darkness for 7 d. Etiolated hypocotyls (6-12 cm in length) were cut off and stored at -20°C until use. Preparation and Characterization of Membrane VesiclesA11 procedures were carried out on ice under room light.The plant material (60-80 g of hypocotyls) was homogenized in a mortar using 2 volumes of buffer A containing 50 mM Tris-HC1, pH 7.5, 2.0 mM EDTA, 250 mM SUC, and 10 mM 2-mercaptoethanol. The homogenate was filtered through four layers of cheeseclo...

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Natural polyamines stimulate G-proteins

Cited by 90 publications

References 37 publications

“Black holes” and bacterial pathogenicity: A large genomic deletion that enhances the virulence of Shigella spp. and enteroinvasive Escherichia coli

“Black holes” and bacterial pathogenicity: A large genomic deletion that enhances the virulence of Shigella spp. and enteroinvasive Escherichia coli

Activation of βγ Subunits of Gi2 and Gi3 Proteins by Basic Secretagogues Induces Exocytosis Through Phospholipase Cβ and Arachidonate Release Through Phospholipase Cγ in Mast Cells

Polyamine Binding to Plasma Membrane Vesicles Isolated from Zucchini Hypocotyls

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