Auto‐inhibition of <i>Arabidopsis thaliana</i> plasma membrane Ca<sup>2+</sup>‐ATPase involves an interaction of the N‐terminus with the small cytoplasmic loop

Luoni, Laura; Meneghelli, S.; Bonza, Maria Cristina; Michelis, Maria Ida De

doi:10.1016/j.febslet.2004.08.003

Cited by 27 publications

(36 citation statements)

References 27 publications

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“…The regulatory region consisting of a CaMBD and an autoinhibitory domain is located in the C terminus in animals and N terminus in plants (9,10). These two domains are likely to be at least partly overlapping in both plant and mammalian Ca 2ϩ -ATPases, as has been shown for the human PMCA4b (isoform 4, splice variant b) (11), Arabidopsis ACA2 (isoform 2) (12,13), and ACA8 (14). In PMCA4b, two residues, Trp-1093 and Asp-1080, are involved in autoinhibition as well as CaM binding (11,(15)(16).…”

Section: Camentioning

confidence: 89%

“…The Autoinhibitory Domain Is Overlapping with the CaM-binding Domain-The mutations made in the CaMBD of ACA8 were also analyzed for their role in autoinhibition of the pump, as the CaMBD and autoinhibitory domain have been shown to be at least partially overlapping in Ca 2ϩ -ATPases of the P 2B subfamily of both animals and plants (11)(12)(13)(14). Six mutants, W47A, R48A, L52A, N55A, R58A, and F60A, did have increased CaM-independent activity compared with the wild type pump (Figs.…”

Section: Discussionmentioning

confidence: 99%

“…Both the autoinhibitory domain and the CaMBD have recently been localized to the N terminus of ACA8 (14,18,19). The CaMBD in ACA8 has been suggested to be localized between residues Ile-41 and 20).…”

Section: Camentioning

confidence: 99%

“…This is mediated by the ␣-helical CaMBD but only by residues situated on one side of the ␣-helix that make interactions to an intramolecular receptor in the pump. In ACA8, an intramolecular site of interaction for the N terminus has been identified in the small cytoplasmic loop (14). The other side of the ␣-helix, presumed to be exposed to the cytosol, contains residues with low affinity to CaM preventing CaM binding at low cytosolic Ca Residues important for CaM recognition are boxed and residues involved in autoinhibition are circled.…”

Section: Amino Acid Residues Involved In Autoinhibition or Recognitiomentioning

confidence: 99%

“…When binding to both sides of the ␣-helix is achieved, the N terminus is released from the intramolecular receptor and the pump is activated. This model only includes autoinhibitory residues identified in the CaMBD of ACA8, although additional autoinhibitory residues may exist in the N terminus outside the CaMBD (14,17). Furthermore, the model only describes how CaM can activate an autoinhibited enzyme, although other regulatory mechanisms may exist.…”

Section: Amino Acid Residues Involved In Autoinhibition or Recognitiomentioning

confidence: 99%

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The Plant Plasma Membrane Ca2+ Pump ACA8 Contains Overlapping as Well as Physically Separated Autoinhibitory and Calmodulin-binding Domains

Bækgaard¹,

Luoni

Michelis

et al. 2006

Journal of Biological Chemistry

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In plant Ca2؉ pumps belonging to the P 2B subfamily of P-type ATPases, the N-terminal cytoplasmic domain is responsible for pump autoinhibition. Binding of calmodulin (CaM) to this region results in pump activation but the structural basis for CaM activation is still not clear. All residues in a putative CaM-binding domain (Arg 43 to Lys 68 ) were mutagenized and the resulting recombinant proteins were studied with respect to CaM binding and the activation state. The results demonstrate that (i) the binding site for CaM is overlapping with the autoinhibitory region and (ii) the autoinhibitory region comprises significantly fewer residues than the CaM-binding region. In a helical wheel projection of the CaM-binding domain, residues involved in autoinhibition cluster on one side of the helix, which is proposed to interact with an intramolecular receptor site in the pump. Residues influencing CaM negatively are situated on the other face of the helix, likely to face the cytosol, whereas residues controlling CaM binding positively are scattered throughout. We propose that early CaM recognition is mediated by the cytosolic face and that CaM subsequently competes with the intramolecular autoinhibitor in binding to the other face of the helix. Ca2ϩ acts as a secondary messenger in eukaryotic cells. One of the key proteins that mediate Ca 2ϩ signals is calmodulin (CaM) 2 a small, ubiquitous, and highly conserved protein found in all eukaryotes (1, 2). Upon Ca 2ϩ binding, CaM changes conformation, which enables CaM to bind to and regulate a wide array of target enzymes. The interaction between CaM and the CaM-binding domain (CaMBD) of the target enzyme is mainly hydrophobic in which two bulky hydrophobic residues in the CaMBD, the so-called anchor points, are especially important to anchor the protein to CaM. In addition, the complex is stabilized by electrostatic interactions between negatively charged glutamates in CaM and basic residues in the CaMBD (3-5). No consensus CaMBD exists for proteins that are targets of CaM, but CaMBDs typically have a hydrophobic and basic nature consisting of 15-30 amino acid residues that have a tendency to form an ␣-helix. Based on the position of the two hydrophobic anchor points, the majority of Ca 2ϩ -dependent CaMBDs is divided into three classes, namely 1-10, 1-14, and 1-16 (6, 7). Many CaM-regulated enzymes are autoinhibited with autoinhibition released by CaM. The autoinhibitory domain is often located either adjacent to or overlapping with the CaMBD (5, 8).The P 2B Ca 2ϩ -ATPases including PMCAs (plasma membrane Ca 2ϩ -ATPases) from animals and ACAs (autoinhibited Ca 2ϩ -ATPases) from plants are autoinhibitory proteins regulated by CaM. The regulatory region consisting of a CaMBD and an autoinhibitory domain is located in the C terminus in animals and N terminus in plants (9, 10). These two domains are likely to be at least partly overlapping in both plant and mammalian Ca 2ϩ -ATPases, as has been shown for the human PMCA4b (isoform 4, splice variant b) (11), Arabidopsis ACA2 (i...

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Section: Camentioning

confidence: 89%

Section: Discussionmentioning

confidence: 99%

Section: Camentioning

confidence: 99%

Section: Amino Acid Residues Involved In Autoinhibition or Recognitiomentioning

confidence: 99%

Section: Amino Acid Residues Involved In Autoinhibition or Recognitiomentioning

confidence: 99%

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The Plant Plasma Membrane Ca2+ Pump ACA8 Contains Overlapping as Well as Physically Separated Autoinhibitory and Calmodulin-binding Domains

Bækgaard¹,

Luoni

Michelis

et al. 2006

Journal of Biological Chemistry

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Plant Type 2B Ca2+-ATPases: The Diversity of Isoforms of the Model Plant Arabidopsis thaliana

Bonza

Luoni

Olivari

et al. 2015

Regulation of Ca2+-ATPases,V-ATPases and F-ATPases

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Ca2+ Pumps and Ca2+ Antiporters in Plant Development

Pittman

Bonza

Michelis

2010

Signaling and Communication in Plants

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Auto‐inhibition of Arabidopsis thaliana plasma membrane Ca²⁺‐ATPase involves an interaction of the N‐terminus with the small cytoplasmic loop

Cited by 27 publications

References 27 publications

The Plant Plasma Membrane Ca2+ Pump ACA8 Contains Overlapping as Well as Physically Separated Autoinhibitory and Calmodulin-binding Domains

The Plant Plasma Membrane Ca2+ Pump ACA8 Contains Overlapping as Well as Physically Separated Autoinhibitory and Calmodulin-binding Domains

Plant Type 2B Ca2+-ATPases: The Diversity of Isoforms of the Model Plant Arabidopsis thaliana

Ca2+ Pumps and Ca2+ Antiporters in Plant Development

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Auto‐inhibition of Arabidopsis thaliana plasma membrane Ca2+‐ATPase involves an interaction of the N‐terminus with the small cytoplasmic loop

Cited by 27 publications

References 27 publications

The Plant Plasma Membrane Ca2+ Pump ACA8 Contains Overlapping as Well as Physically Separated Autoinhibitory and Calmodulin-binding Domains

The Plant Plasma Membrane Ca2+ Pump ACA8 Contains Overlapping as Well as Physically Separated Autoinhibitory and Calmodulin-binding Domains

Plant Type 2B Ca2+-ATPases: The Diversity of Isoforms of the Model Plant Arabidopsis thaliana

Ca2+ Pumps and Ca2+ Antiporters in Plant Development

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Auto‐inhibition of Arabidopsis thaliana plasma membrane Ca²⁺‐ATPase involves an interaction of the N‐terminus with the small cytoplasmic loop