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Enzymatic systems of inorganic pyrophosphate bioenergetics in photosynthetic and heterotrophic protists: remnants or metabolic cornerstones?
Pérez-Castiñeira, José; Gómez-García, Rosario; López Marqués, Rosa; Losada, Manuel; Serrano, Aurelio.
Afiliação
  • Pérez-Castiñeira, José; Universidad de Sevilla. Centro de Insvestigaciones Cientíicas "Isla de la Cartuja". Sevilla. España
  • Gómez-García, Rosario; Universidad de Sevilla. Centro de Insvestigaciones Cientíicas "Isla de la Cartuja". Sevilla. España
  • López Marqués, Rosa; Universidad de Sevilla. Centro de Insvestigaciones Cientíicas "Isla de la Cartuja". Sevilla. España
  • Losada, Manuel; Universidad de Sevilla. Centro de Insvestigaciones Cientíicas "Isla de la Cartuja". Sevilla. España
  • Serrano, Aurelio; Universidad de Sevilla. Centro de Insvestigaciones Cientíicas "Isla de la Cartuja". Sevilla. España
Int. microbiol ; 4(3): 135-142, sept. 2001. ilus, tab
Artigo em Inglês | IBECS | ID: ibc-23245
Biblioteca responsável: ES1.1
Localização: ES1.1 - BNCS
ABSTRACT
An increasing body of biochemical and genetic evidence suggests that inorganic pyrophosphate (PPi) plays an important role in protist bioenergetics. In these organisms, two types of inorganic pyrophosphatases [EC 3.6.1.1, namely soluble PPases (sPPases) and proton-translocating PPases (H+-PPases)] that hydrolyse the PPi generated by cell anabolism, thereby replenishing the orthophosphate pool needed for phosphorylation reactions, are present in different cellular compartments. Photosynthetic and heterotrophic protists possess sPPases located in cellular organelles (plastids and mitochondria), where many anabolic and biosynthetic reactions take place, in addition to H+-PPases, which are integral membrane proteins of the vacuolysosomal membranes and use the chemical energy of PPi to generate an electrochemical proton gradient useful in cell bioenergetics. This last category of proton pumps was considered to be restricted to higher plants and some primitive photosynthetic bacteria, but it has been found recently in many protists (microalgae and protozoa) and bacteria, thus indicating that H+-PPases are much more widespread than previously thought. No cytosolic sPPase (in bacteria, fungi and animal cells) has been shown to occur in these lower eukaryotes. The widespread occurrence of these key enzymes of PPi metabolism among evolutionarily divergent protists strongly supports the ancestral character of the bioenergetics based on this simple energy-rich compound, which may play an important role in survival under different biotic and abiotic stress conditions (AU)
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Coleções: Bases de dados nacionais / Espanha Base de dados: IBECS Assunto principal: Pirofosfatases / Difosfatos / Eucariotos Limite: Animais Idioma: Inglês Revista: Int. microbiol Ano de publicação: 2001 Tipo de documento: Artigo Instituição/País de afiliação: Universidad de Sevilla/España
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Coleções: Bases de dados nacionais / Espanha Base de dados: IBECS Assunto principal: Pirofosfatases / Difosfatos / Eucariotos Limite: Animais Idioma: Inglês Revista: Int. microbiol Ano de publicação: 2001 Tipo de documento: Artigo Instituição/País de afiliação: Universidad de Sevilla/España
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