ACA8 is a plasma membrane (PM) Ca2+-ATPase of A. thaliana which has an extended N-te containing both an autoinhibitory domain and a calmodulin (CaM) binding site: CaM binding suppresses autoinhibition. This regulatory mechanism is similar to that of animal PM Ca2+ ATPase and plant PM H+-ATPase, but in these proteins the regulatory site is localised in the C-te. To analyse in details the autoinbitory mechanism, mutants in which the N-te of ACA8 is inserted at the C-te of the protein have been constructed using the cDNA of CaM insensitive mutant ï „74-ACA8. Moreover, chimeras in which ï „74-ACA8 is fused to the C-te domains of AHA1 (isoform 1 of A. thaliana PM proton pump) or of PMCA4b (isoform 4b of human PM Ca2+-ATPase) have been produced. All mutants expressed in the S. cerevisiae strain K616 are functional. Results show that repositioning the N-te region of ACA8 to the C-te of the protein does not interfere with its ability to autoinhibit the pump, thus the regulatory function of the terminal domain is independent from its position in ACA8. A detailed characterisation of the chimeras analysing their activity in presence of 14-3-3 and fusicoccin or CaM is in progress

Arabidopsis thaliana plasma membrane Ca2+-ATPase isoform 8: molecular analysis of the autoinhibitory mechanism using chimeras / M.C. Bonza, L. Luoni, S. Visconti. ((Intervento presentato al 1. convegno Congress SIBV tenutosi a Verona nel 2009.

Arabidopsis thaliana plasma membrane Ca2+-ATPase isoform 8: molecular analysis of the autoinhibitory mechanism using chimeras

M.C. Bonza
Primo
;
L. Luoni
Secondo
;
2009-07

Abstract

ACA8 is a plasma membrane (PM) Ca2+-ATPase of A. thaliana which has an extended N-te containing both an autoinhibitory domain and a calmodulin (CaM) binding site: CaM binding suppresses autoinhibition. This regulatory mechanism is similar to that of animal PM Ca2+ ATPase and plant PM H+-ATPase, but in these proteins the regulatory site is localised in the C-te. To analyse in details the autoinbitory mechanism, mutants in which the N-te of ACA8 is inserted at the C-te of the protein have been constructed using the cDNA of CaM insensitive mutant ï „74-ACA8. Moreover, chimeras in which ï „74-ACA8 is fused to the C-te domains of AHA1 (isoform 1 of A. thaliana PM proton pump) or of PMCA4b (isoform 4b of human PM Ca2+-ATPase) have been produced. All mutants expressed in the S. cerevisiae strain K616 are functional. Results show that repositioning the N-te region of ACA8 to the C-te of the protein does not interfere with its ability to autoinhibit the pump, thus the regulatory function of the terminal domain is independent from its position in ACA8. A detailed characterisation of the chimeras analysing their activity in presence of 14-3-3 and fusicoccin or CaM is in progress
plasma membrane ; Ca2+-ATPase ; H+-ATPase.
Settore BIO/04 - Fisiologia Vegetale
Società Italiana di Biologia Vegetale
Arabidopsis thaliana plasma membrane Ca2+-ATPase isoform 8: molecular analysis of the autoinhibitory mechanism using chimeras / M.C. Bonza, L. Luoni, S. Visconti. ((Intervento presentato al 1. convegno Congress SIBV tenutosi a Verona nel 2009.
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Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/2434/142378
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