Relationship between intracellular calcium and morphologic changes in rabbit erythrocytes: Effects of the acylated and unacylated forms of E. coli alpha-hemolysin

Alpha-hemolysin (HlyA) is a hemolytic and cytotoxic protein secreted by uropathogenic Escherichia coli strains, whose expression correlates with the severity of the infections produced. HlyA is synthesized as a protoxin, ProHlyA, that becomes matured to the active form in the cytosol by hemolysin-C-...

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Detalles Bibliográficos
Autores principales:	Vázquez, Romina Florencia, Maté, Sabina María, Bakás, Laura Susana, Muñoz-Garay, Carlos, Herlax, Vanesa Silvana
Formato:	Articulo
Lenguaje:	Inglés
Publicado:	2016
Materias:	Bioquímica Calcium Discocyte-echinocyte-spherocyte transition Exovesicles HlyA Purinergic receptors RTX toxins Unacylated protein
Acceso en línea:	http://sedici.unlp.edu.ar/handle/10915/86761
Aporte de:	SEDICI (UNLP) de Universidad Nacional de La Plata

id	I19-R120-10915-86761
record_format	dspace
institution	Universidad Nacional de La Plata
institution_str	I-19
repository_str	R-120
collection	SEDICI (UNLP)
language	Inglés
topic	Bioquímica Calcium Discocyte-echinocyte-spherocyte transition Exovesicles HlyA Purinergic receptors RTX toxins Unacylated protein
spellingShingle	Bioquímica Calcium Discocyte-echinocyte-spherocyte transition Exovesicles HlyA Purinergic receptors RTX toxins Unacylated protein Vázquez, Romina Florencia Maté, Sabina María Bakás, Laura Susana Muñoz-Garay, Carlos Herlax, Vanesa Silvana Relationship between intracellular calcium and morphologic changes in rabbit erythrocytes: Effects of the acylated and unacylated forms of E. coli alpha-hemolysin
topic_facet	Bioquímica Calcium Discocyte-echinocyte-spherocyte transition Exovesicles HlyA Purinergic receptors RTX toxins Unacylated protein
description	Alpha-hemolysin (HlyA) is a hemolytic and cytotoxic protein secreted by uropathogenic Escherichia coli strains, whose expression correlates with the severity of the infections produced. HlyA is synthesized as a protoxin, ProHlyA, that becomes matured to the active form in the cytosol by hemolysin-C-directed fatty acylation at the ϵ-Amino residues of Lys 564 and Lys 690, before export from the toxin-producing bacteria. This posttranslational modification is remarkable because the nature of the protein is changed by the lipidic moiety from a benign protein to a frank toxin. In the present work, we demonstrated for the first time that, despite being hemolitically inactive, ProHlyA induced cellular morphologic changes in rabbit erythrocytes. A discocyte-to-echinocyte transformation was triggered by the protoxin in the absence of any accompanying increase in intracellular-Ca2 + levels. In addition, the Ca2 +-influx kinetics in HlyA-treated erythrocytes indicated that the active toxin induced an elevation in intraerythrocyte-Ca2 + content in a biphasic manner, with an initial rise in Ca2 + that depended on the association of the protein with the target membrane and a second increment corresponding to an activation of purinergic channels. The first increase was sufficient to trigger a discocyte-echinocyte-spherocyte transition in erythrocyte shape, though the subsequent rise mediated by purinergic signalling was essential for the occurrence of hemolysis. The results presented here provide new insights into the mechanism of action of this toxin.
format	Articulo Articulo
author	Vázquez, Romina Florencia Maté, Sabina María Bakás, Laura Susana Muñoz-Garay, Carlos Herlax, Vanesa Silvana
author_facet	Vázquez, Romina Florencia Maté, Sabina María Bakás, Laura Susana Muñoz-Garay, Carlos Herlax, Vanesa Silvana
author_sort	Vázquez, Romina Florencia
title	Relationship between intracellular calcium and morphologic changes in rabbit erythrocytes: Effects of the acylated and unacylated forms of E. coli alpha-hemolysin
title_short	Relationship between intracellular calcium and morphologic changes in rabbit erythrocytes: Effects of the acylated and unacylated forms of E. coli alpha-hemolysin
title_full	Relationship between intracellular calcium and morphologic changes in rabbit erythrocytes: Effects of the acylated and unacylated forms of E. coli alpha-hemolysin
title_fullStr	Relationship between intracellular calcium and morphologic changes in rabbit erythrocytes: Effects of the acylated and unacylated forms of E. coli alpha-hemolysin
title_full_unstemmed	Relationship between intracellular calcium and morphologic changes in rabbit erythrocytes: Effects of the acylated and unacylated forms of E. coli alpha-hemolysin
title_sort	relationship between intracellular calcium and morphologic changes in rabbit erythrocytes: effects of the acylated and unacylated forms of e. coli alpha-hemolysin
publishDate	2016
url	http://sedici.unlp.edu.ar/handle/10915/86761
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Relationship between intracellular calcium and morphologic changes in rabbit erythrocytes: Effects of the acylated and unacylated forms of E. coli alpha-hemolysin

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