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A functional calcium-transporting ATPase encoded by chlorella viruses.

Bonza, Maria Cristina and Martin, Holger and Kang, Ming and Lewis, Gentry and Greiner, Timo and Giacometti, Sonia and Van Etten, James L. and De Michelis, Maria Ida and Thiel, Gerhard and Moroni, Anna (2010):
A functional calcium-transporting ATPase encoded by chlorella viruses.
In: The Journal of general virology, pp. 2620-9, 91, (Pt 10), ISSN 1465-2099,
[Article]

Abstract

Calcium-transporting ATPases (Ca(2+) pumps) are major players in maintaining calcium homeostasis in the cell and have been detected in all cellular organisms. Here, we report the identification of two putative Ca(2+) pumps, M535L and C785L, encoded by chlorella viruses MT325 and AR158, respectively, and the functional characterization of M535L. Phylogenetic and sequence analyses place the viral proteins in group IIB of P-type ATPases even though they lack a typical feature of this class, a calmodulin-binding domain. A Ca(2+) pump gene is present in 45 of 47 viruses tested and is transcribed during virus infection. Complementation analysis of the triple yeast mutant K616 confirmed that M535L transports calcium ions and, unusually for group IIB pumps, also manganese ions. In vitro assays show basal ATPase activity. This activity is inhibited by vanadate, but, unlike that of other Ca(2+) pumps, is not significantly stimulated by either calcium or manganese. The enzyme forms a (32)P-phosphorylated intermediate, which is inhibited by vanadate and not stimulated by the transported substrate Ca(2+), thus confirming the peculiar properties of this viral pump. To our knowledge this is the first report of a functional P-type Ca(2+)-transporting ATPase encoded by a virus.

Item Type: Article
Erschienen: 2010
Creators: Bonza, Maria Cristina and Martin, Holger and Kang, Ming and Lewis, Gentry and Greiner, Timo and Giacometti, Sonia and Van Etten, James L. and De Michelis, Maria Ida and Thiel, Gerhard and Moroni, Anna
Title: A functional calcium-transporting ATPase encoded by chlorella viruses.
Language: English
Abstract:

Calcium-transporting ATPases (Ca(2+) pumps) are major players in maintaining calcium homeostasis in the cell and have been detected in all cellular organisms. Here, we report the identification of two putative Ca(2+) pumps, M535L and C785L, encoded by chlorella viruses MT325 and AR158, respectively, and the functional characterization of M535L. Phylogenetic and sequence analyses place the viral proteins in group IIB of P-type ATPases even though they lack a typical feature of this class, a calmodulin-binding domain. A Ca(2+) pump gene is present in 45 of 47 viruses tested and is transcribed during virus infection. Complementation analysis of the triple yeast mutant K616 confirmed that M535L transports calcium ions and, unusually for group IIB pumps, also manganese ions. In vitro assays show basal ATPase activity. This activity is inhibited by vanadate, but, unlike that of other Ca(2+) pumps, is not significantly stimulated by either calcium or manganese. The enzyme forms a (32)P-phosphorylated intermediate, which is inhibited by vanadate and not stimulated by the transported substrate Ca(2+), thus confirming the peculiar properties of this viral pump. To our knowledge this is the first report of a functional P-type Ca(2+)-transporting ATPase encoded by a virus.

Journal or Publication Title: The Journal of general virology
Volume: 91
Number: Pt 10
Divisions: 10 Department of Biology > Plant Membrane Biophysics
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10 Department of Biology
Date Deposited: 21 Jun 2011 11:55
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