Mutation of calmodulin-binding site renders the Na+/H+ exchanger (NHE1) highly H(+)-sensitive and Ca2+ regulation-defective.

Wakabayashi, Shigeo; Bertrand, Bénédicte; Ikeda, Toshitaro; Pouysségur, Jacques; Shigekawa, Munekazu

doi:10.1016/s0021-9258(17)36888-6

Cited by 226 publications

(31 citation statements)

References 34 publications

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“…NHE1 contains two functional domains: the NH 2 terminus transmembrane domain, which is necessary and sufficient to catalyze ion translocation, and the COOH terminus cytoplasmic domain, which is crucial for modulating NHE1 activity. This COOH terminus domain is associated with a number of functionally distinct signaling molecules, i.e., phosphatidylinositol 4,5-bisphosphate (2), calcineurin B homologous protein (CHP) (40,47,48), actin-binding proteins of the ezrin, radixin, moesin (ERM) family (18), Nck-interacting kinase (NIK) (77), Ca 2ϩ /calmodulin (71,72), adaptor protein 14-3-3␤ (38), heat shock protein (HSP)70 (59), and carbonic anhydrase II (39).…”

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confidence: 99%

“…Thus cells become alkalinized and allow the progression of certain biological processes. Modulation of NHE1 activity occurs at the COOH terminus by at least three mechanisms: 1) phosphorylation, such as by ERK-regulated p90 ribosomal S6 kinase (62) in response to growth factor signals; 2) the binding of regulatory proteins with conformational changes, such as the association of Ca 2ϩ /calmodulin (CaM) to the high-affinity CaM domain of NHE1, which relieves an autoinhibitory intramolecular interaction, thereby enhancing NHE1 activity (71,72); and 3) affinity alteration of the transmembrane internal H ϩ transporter site (35).…”

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confidence: 99%

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Novel functional interaction between Na⁺/H⁺exchanger 1 and tyrosine phosphatase SHP-2

Xue¹,

Zhou²,

Yao³

et al. 2007

American Journal of Physiology-Regulatory, Integrative and Comp

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Besides being a intracellular pH (pHi) regulator, Na+/H+ exchanger (NHE)1 has recently been postulated as a membrane scaffold that assembles protein complexes and coordinates various signaling pathways. The aim of the present study was to uncover NHE1 interactive partners and study their functional implications. NHE1 interactive partners were screened in the mouse brain with a signal transduction AntibodyArray. Ten of 400 tested proteins appeared to be potentially associated with NHE1. These partners have been shown to be involved in either cell proliferative or apoptotic pathways. The interactions between NHE1 and Src homology 2 domain-containing protein tyrosine phosphatase (SHP-2), Bin1, and heat shock protein (HSP)70 were reciprocally confirmed by coimmunoprecipitation. Moreover, in vitro binding data have shown that NHE1 COOH terminus interacts directly with SHP-2. The functional significance of the association between NHE1 and SHP-2 was further investigated by measuring pHi, cell proliferation, and cell death with the fluorescent dye BCECF, [3H]thymidine incorporation, and medium lactate dehydrogenase activity, respectively. Our results revealed that cells with SHP-2 overexpression exhibited a higher steady-state pHi and a faster, NHE1-dependent pHi recovery rate from acid load in HEPES buffer. In addition, SHP-2 overexpression diminished the HOE-642-induced inhibition of cell proliferation and protected cells from hypoxic injury, especially in the presence of HOE-642. Together, our findings demonstrate that SHP-2 not only is physically associated with NHE1 but also modulates NHE1 functions such as pHi regulation, cell proliferation, and cell death under hypoxia.

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confidence: 99%

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confidence: 99%

Novel functional interaction between Na⁺/H⁺exchanger 1 and tyrosine phosphatase SHP-2

Xue¹,

Zhou²,

Yao³

et al. 2007

American Journal of Physiology-Regulatory, Integrative and Comp

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“…This report shows that the C-terminal tail of this transporter contains two nearby CBSs located at amino acid residues 629-652 (proximal) and 658-671 (distal), respectively. It has been proposed that in resting cells, when the cytosolic concentration of Ca 2+ is very low, the distal CBS interacts with the so-called proton modifier site (PMS), located in the C-terminal end of an intramembrane loop, inducing autoinhibition [191,192]. Moreover, it has been hypothesized that the proximal CBS also interacts electrostatically with a highly acidic cluster (amino acid residues 753-759) distal of the CBSs [191,193].…”

Section: Transport Systemsmentioning

confidence: 99%

“…Moreover, it has been hypothesized that the proximal CBS also interacts electrostatically with a highly acidic cluster (amino acid residues 753-759) distal of the CBSs [191,193]. This region may have the functional characteristics of a non-EF-hand CLBS described above and has been proposed to be involved in maintaining an adequate conformation of the cytosolic domain, promoting CaM binding and activation of the exchanger [191][192][193]. When the cytosolic Ca 2+ concentration increases, Ca 2+ /CaM binds with the N-lobe to distal CBS and with the C-lobe to proximal CBS [191] and this releases the autoinhibitory/distal CBS from the PMS leading to activation of the exchanger, at the same time that the CLBS is detached from the CBSs.…”

Section: Transport Systemsmentioning

confidence: 99%

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Proteins with calmodulin-like domains: structures and functional roles

Villalobo

González‐Muñoz

Berchtold

2019

Cell. Mol. Life Sci.

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The appearance of modular proteins is a widespread phenomenon during the evolution of proteins. The combinatorial arrangement of different functional and/or structural domains within a single polypeptide chain yields a wide variety of activities and regulatory properties to the modular proteins. In this review, we will discuss proteins, that in addition to their catalytic, transport, structure, localization or adaptor functions, also have segments resembling the helix-loop-helix EF-hand motifs found in Ca 2+ -binding proteins, such as calmodulin (CaM). These segments are denoted CaM-like domains (CaM-LDs) and play a regulatory role, making these CaM-like proteins sensitive to Ca 2+ transients within the cell, and hence are able to transduce the Ca 2+ signal leading to specific cellular responses. Importantly, this arrangement allows to this group of proteins direct regulation independent of other Ca 2+ -sensitive sensor/transducer proteins, such as CaM. In addition, this review also covers CaM-binding proteins, in which their CaM-binding site (CBS), in the absence of CaM, is proposed to interact with other segments of the same protein denoted CaM-like binding site (CLBS). CLBS are important regulatory motifs, acting either by keeping these CaM-binding proteins inactive in the absence of CaM, enhancing the stability of protein complexes and/or facilitating their dimerization via CBS/CLBS interaction. The existence of proteins containing CaM-LDs or CLBSs substantially adds to the enormous versatility and complexity of Ca 2+ /CaM signaling. Keywords α-Actinin • Calcineurin • Calpain • Epidermal growth factor receptor • Glycerol-3-phosphate dehydrogenase • NADPH oxidases • Na + /H + exchanger • Plasma membrane Ca 2+ -ATPase • Protein kinases Abbreviations ADF Actin-depolymerizing factor Bak Bcl2-antagonist/killer CAIN Calcium and internalization CaM Calmodulin CaM-BD CaM-binding domain CaMK-II CaM-dependent protein kinase-II CaM-LD CaM-like domain CaN-A Calcineurin A CaN-B Calcineurin B CBS Calmodulin binding site CDK Cyclin-dependent kinase CDPK/CPK CaM-like domain protein kinase/Ca 2+dependent protein kinase c-erbB Cellular erythroblastic leukemia viral oncogene homologue CLBS Calmodulin-like binding site COMP Cartilage oligomeric matrix protein DAPK1 Death-associated protein kinase 1 ER Endoplasmic reticulum ErbB1/2/3/4 Erythroblastic leukemia viral oncogene homologues 1/2/3/4 EGF Epidermal growth factor EGFR EGF receptor EGFR cyt EGFR cytosolic region FRET Fluorescence resonance energy transfer FSH Follicle-stimulating hormone GPDH Glycerol-3-phosphate dehydrogenase IgA/IgG Immunoglobulins A/G IP 3 Inositol-1,4,5-trisphosphate MAPK1 Mitogen-activated protein kinase 1

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Examination of the role for Ca2+ in regulation and phosphorylation of the Na+/H+ antiporter NHE1 via mitogen and hypertonic stimulation

McSwine

Villereal

1996

J. Cell. Physiol.

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It has been suggested that Ca2+ transients, acting through calmodulin-binding proteins, play a role in the activation of the Na+/H+ exchanger isoform NHE1 (Owen and Villereal, 1982a, Biochem. Biophys. Res. Commun., 109:762-768; 1982b, Proc. Natl. Acad. Sci. U.S.A., 79:3537-3541, Ober and Pardee, 1987, J. Cell. Physiol., 132:311-317). This is supported by a recent report that NHE1 is a calmodulin-binding protein and that loss of the high-affinity calmodulin-binding site results in alterations in antiporter function (Bertrand, et al., 1994, J. Biol. Chem., 269:13703-13709). An additional mechanism by which NHE1 is activated by mitogens is thought to be phosphorylation (Sardet, et al., 1990, Science 247:723-726). Although the calmodulin-binding region appears vital to antiporter activation, the role of phosphorylation is unclear. The studies presented here examine a role for Ca2+ in the activation and phosphorylation of NHE1 induced by serum and hypertonicity. It is apparent that the microsomal Ca2+ ATPase inhibitor thapsigargin activates antiporter function in human foreskin fibroblasts (HSWP) as determined by increased intracellular alkalinization examined by image analysis. This effect is Ca(2+)-dependent as the alkalinization is blocked when cells are preincubated with BAPTA, an intracellular Ca2+ chelator. Similarly, the effects of serum-induced intracellular alkalinization are inhibited by BAPTA. In contrast, activation of NHE1 by increased osmolarity was not inhibited by BAPTA. This suggests that serum, and not hypertonicity, increases intracellular pH via a Ca(2+)-dependent process. It was also observed that both thapsigargin and hypertonicity activate NHE1 by a phosphorylation-independent mechanism and that BAPTA did not block the serum-induced increase in phosphorylation of NHE1. These results indicate that Ca2+ plays the predominant role in the serum-induced activation of NHE1, while phosphorylation plays only a minor, if any, role in this process. However, Ca2+ does not appear to be involved in the osmotic regulation of NHE1.

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Mutation of calmodulin-binding site renders the Na+/H+ exchanger (NHE1) highly H(+)-sensitive and Ca2+ regulation-defective.

Cited by 226 publications

References 34 publications

Novel functional interaction between Na⁺/H⁺exchanger 1 and tyrosine phosphatase SHP-2

Novel functional interaction between Na⁺/H⁺exchanger 1 and tyrosine phosphatase SHP-2

Proteins with calmodulin-like domains: structures and functional roles

Examination of the role for Ca2+ in regulation and phosphorylation of the Na+/H+ antiporter NHE1 via mitogen and hypertonic stimulation

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Mutation of calmodulin-binding site renders the Na+/H+ exchanger (NHE1) highly H(+)-sensitive and Ca2+ regulation-defective.

Cited by 226 publications

References 34 publications

Novel functional interaction between Na+/H+exchanger 1 and tyrosine phosphatase SHP-2

Novel functional interaction between Na+/H+exchanger 1 and tyrosine phosphatase SHP-2

Proteins with calmodulin-like domains: structures and functional roles

Examination of the role for Ca2+ in regulation and phosphorylation of the Na+/H+ antiporter NHE1 via mitogen and hypertonic stimulation

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About

Novel functional interaction between Na⁺/H⁺exchanger 1 and tyrosine phosphatase SHP-2

Novel functional interaction between Na⁺/H⁺exchanger 1 and tyrosine phosphatase SHP-2