scholarly journals Cloning and Characterization of a Potassium-Dependent Sodium/Calcium Exchanger in Drosophila

1999 ◽  
Vol 147 (3) ◽  
pp. 659-670 ◽  
Author(s):  
K. Haug-Collet ◽  
B. Pearson ◽  
R. Webel ◽  
R.T. Szerencsei ◽  
R.J. Winkfein ◽  
...  
Keyword(s):  
Critical Role ◽  
Sodium Calcium Exchanger ◽  
Intracellular Loop ◽  
Excitable Cells ◽  
Sodium Calcium ◽  
Membrane Spanning ◽  
Membrane Spanning Domains ◽  
Antennal Disc ◽  
Stimulation Of

Sodium/calcium(-potassium) exchangers (NCX and NCKX) are critical for the rapid extrusion of calcium, which follows the stimulation of a variety of excitable cells. To further understand the mechanisms of calcium regulation in signaling, we have cloned a Drosophila sodium/calcium-potassium exchanger, Nckx30C. The overall deduced protein topology for NCKX30C is similar to that of mammalian NCKX, having five membrane-spanning domains in the NH2 terminus separated from six at the COOH-terminal end by a large intracellular loop. We show that NCKX30C functions as a potassium-dependent sodium/calcium exchanger, and is not only expressed in adult neurons as was expected, but is also expressed during ventral nerve cord development in the embryo and in larval imaginal discs. Nckx30C is expressed in a dorsal–ventral pattern in the eye-antennal disc in a pattern that is similar to, but broader than that of wingless, suggesting that large fluxes of calcium may be occurring during imaginal disc development. Nckx30C may not only function in the removal of calcium and maintenance of calcium homeostasis during signaling in the adult, but may also play a critical role in signaling during development.

Initial Characterization of the Feline Sodium-Calcium Exchanger Genea

1996 ◽  
Vol 779 (1) ◽  
pp. 121-125 ◽  
Author(s):  
KIMBERLY V. BARNES ◽  
MYRA M. DAWSON ◽  
DONALD R. MENICK
Keyword(s):  
Sodium Calcium Exchanger ◽  
Sodium Calcium ◽  
Initial Characterization

Characterization of aflJ, a Gene Required for Conversion of Pathway Intermediates to Aflatoxin

1998 ◽  
Vol 64 (10) ◽  
pp. 3713-3717 ◽  
Author(s):  
D. M. Meyers ◽  
G. Obrian ◽  
W. L. Du ◽  
D. Bhatnagar ◽  
G. A. Payne
Keyword(s):  
Biosynthetic Pathway ◽  
Regulatory Gene ◽  
Regulatory Function ◽  
Norsolorinic Acid ◽  
Genes Encoding ◽  
Targeting Signal ◽  
Dna Fragment ◽  
Membrane Spanning ◽  
Membrane Spanning Domains

The genes encoding the aflatoxin biosynthetic pathway enzymes have been localized as a cluster to a 75-kb DNA fragment. The enzymatic functions of the products of most of the genes in the cluster are known, but there are a few genes that have not yet been characterized. We report here the characterization of one of these genes, a gene designated aflJ. This gene resides in the cluster adjacent to the pathway regulatory gene, aflR, and the two genes are divergently transcribed. Disruption of aflJ inAspergillus flavus results in a failure to produce aflatoxins and a failure to convert exogenously added pathway intermediates norsolorinic acid, sterigmatocystin, andO-methylsterigmatocystin to aflatoxin. The disrupted strain does, however, accumulate pksA, nor-1,ver-1, and omtA transcripts under conditions conducive to aflatoxin biosynthesis. Therefore, disruption ofaflJ does not affect transcription of these genes, andaflJ does not appear to have a regulatory function similar to that of aflR. Sequence analysis of aflJ and its putative peptide, AflJ, did not reveal any enzymatic domains or significant similarities to proteins of known function. The putative peptide does contain three regions predicted to be membrane-spanning domains and a microbodies C-terminal targeting signal.

scholarly journals A Critical Role for the Potassium-Dependent Sodium-Calcium Exchanger NCKX2 in Protection against Focal Ischemic Brain Damage

2008 ◽  
Vol 28 (9) ◽  
pp. 2053-2063 ◽  
Author(s):  
O. Cuomo ◽  
R. Gala ◽  
G. Pignataro ◽  
F. Boscia ◽  
A. Secondo ◽  
...  
Keyword(s):  
Brain Damage ◽  
Critical Role ◽  
Sodium Calcium Exchanger ◽  
Ischemic Brain Damage ◽  
Ischemic Brain ◽  
Sodium Calcium

Identification and Characterization of a Sodium/Calcium Exchanger, NCX-1, in Osteoclasts and Its Role in Bone Resorption

2001 ◽  
Vol 283 (4) ◽  
pp. 770-775 ◽  
Author(s):  
Baljit S. Moonga ◽  
Robert Davidson ◽  
Li Sun ◽  
Olugbenga A. Adebanjo ◽  
James Moser ◽  
...  
Keyword(s):  
Bone Resorption ◽  
Sodium Calcium Exchanger ◽  
Sodium Calcium ◽  
Identification And Characterization

scholarly journals Design of a Proteolytically Stable Sodium-Calcium Exchanger 1 Activator Peptide for In Vivo Studies

2021 ◽  
Vol 12 ◽  
Author(s):  
Pimthanya Wanichawan ◽  
Jonas Skogestad ◽  
Marianne Lunde ◽  
Thea Parsberg Støle ◽  
Maria Stensland ◽  
...  
Keyword(s):  
Direct Interaction ◽  
Mass Spectrometry Analysis ◽  
In Vivo Studies ◽  
Physical Interaction ◽  
Sodium Calcium Exchanger ◽  
Intracellular Loop ◽  
Binding Peptide ◽  
Spectrometry Analysis ◽  
Sodium Calcium

The cardiac sodium–calcium exchanger (NCX1) is important for normal Na+- and Ca2+-homeostasis and cardiomyocyte relaxation and contraction. It has been suggested that NCX1 activity is reduced by phosphorylated phospholemman (pSer68-PLM); however its direct interaction with PLM is debated. Disruption of the potentially inhibitory pSer68-PLM-NCX1 interaction might be a therapeutic strategy to increase NCX1 activity in cardiac disease. In the present study, we aimed to analyze the binding affinities and kinetics of the PLM-NCX1 and pSer68-PLM-NCX1 interactions by surface plasmon resonance (SPR) and to develop a proteolytically stable NCX1 activator peptide for future in vivo studies. The cytoplasmic parts of PLM (PLMcyt) and pSer68-PLM (pSer68-PLMcyt) were found to bind strongly to the intracellular loop of NCX1 (NCX1cyt) with similar KD values of 4.1 ± 1.0 nM and 4.3 ± 1.9 nM, but the PLMcyt-NCX1cyt interaction showed higher on/off rates. To develop a proteolytically stable NCX1 activator, we took advantage of a previously designed, high-affinity PLM binding peptide (OPT) that was derived from the PLM binding region in NCX1 and that reverses the inhibitory PLM (S68D)-NCX1 interaction in HEK293. We performed N- and C-terminal truncations of OPT and identified PYKEIEQLIELANYQV as the minimum sequence required for pSer68-PLM binding. To increase peptide stability in human serum, we replaced the proline with an N-methyl-proline (NOPT) after identification of N-terminus as substitution tolerant by two-dimensional peptide array analysis. Mass spectrometry analysis revealed that the half-life of NOPT was increased 17-fold from that of OPT. NOPT pulled down endogenous PLM from rat left ventricle lysate and exhibited direct pSer68-PLM binding in an ELISA-based assay and bound to pSer68-PLMcyt with a KD of 129 nM. Excess NOPT also reduced the PLMcyt-NCX1cyt interaction in an ELISA-based competition assay, but in line with that NCX1 and PLM form oligomers, NOPT was not able to outcompete the physical interaction between endogenous full length proteins. Importantly, cell-permeable NOPT-TAT increased NCX1 activity in cardiomyocytes isolated from both SHAM-operated and aorta banded heart failure (HF) mice, indicating that NOPT disrupted the inhibitory pSer68-PLM-NCX1 interaction. In conclusion, we have developed a proteolytically stable NCX1-derived PLM binding peptide that upregulates NCX1 activity in SHAM and HF cardiomyocytes.

scholarly journals Discovery and characterization of ORM‐11372, a novel inhibitor of the sodium‐calcium exchanger with positive inotropic activity

2020 ◽  
Vol 177 (24) ◽  
pp. 5534-5554
Author(s):  
Leena Otsomaa ◽  
Jouko Levijoki ◽  
Gerd Wohlfahrt ◽  
Hugh Chapman ◽  
Ari‐Pekka Koivisto ◽  
...  
Keyword(s):  
Sodium Calcium Exchanger ◽  
Inotropic Activity ◽  
Sodium Calcium

scholarly journals An amphipathic α-helix directs palmitoylation of the large intracellular loop of the sodium/calcium exchanger

2017 ◽  
Vol 292 (25) ◽  
pp. 10745-10752 ◽  
Author(s):  
Fiona Plain ◽  
Samitha Dilini Congreve ◽  
Rachel Sue Zhen Yee ◽  
Jennifer Kennedy ◽  
Jacqueline Howie ◽  
...  
Keyword(s):  
Sodium Calcium Exchanger ◽  
Intracellular Loop ◽  
Sodium Calcium ◽  
Α Helix

Biochemical and Molecular Characterization of the Sodium-Calcium Exchanger from Bovine Rod Photoreceptors

1991 ◽  
Vol 639 (1 Sodium-Calciu) ◽  
pp. 234-244 ◽  
Author(s):  
ANITA ACHILLES ◽  
UTE FRIEDEL ◽  
WINFRIED HAASE ◽  
HELMUT REILÄNDER ◽  
NEIL J. COOK
Keyword(s):  
Molecular Characterization ◽  
Sodium Calcium Exchanger ◽  
Rod Photoreceptors ◽  
Sodium Calcium
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