caa a22 4500 606235612 CHVBK 20210128101243.0 cr unu---uuuuu 210128e20150901xx s 000 0 eng 10.1007/s11010-015-2473-4 doi (NATIONALLICENCE)springer-10.1007/s11010-015-2473-4 Regulation of GAP43/calmodulin complex formation via calcineurin-dependent mechanism in differentiated PC12 cells with altered PMCA isoforms composition [Elektronische Daten] [Tomasz Boczek, Bozena Ferenc, Malwina Lisek, Ludmila Zylinska] Several lines of evidence suggest the contribution of age-related decline in plasma membrane calcium pump (PMCA) to the onset ofneurodegenerative diseases.From four PMCA isoforms, PMCA2, and PMCA3 respond to a rapid removal of Ca2+ and are expressed predominantly in excitable cells. We have previously shown that suppression of neuron-specific PMCAs in differentiated PC12 cellsaccelerated cell differentiation, butincreased apoptosis in PMCA2-deficient line. We also demonstrated thataltered expression of voltage-dependent calcium channels correlated with their higher contribution to Ca2+ influx, which varied between PMCA-reduced lines. Here, we propose a mechanism unique for differentiated PC12 cells by which PMCA2 and PMCA3 regulate pGAP43/GAP43 ratio and the interaction between GAP43 and calmodulin (CaM). Although down-regulation of PMCA2 or PMCA3 altered the content of GAP43/pGAP43, of paramount importance for the regulatory mechanism is a disruption of isoform-specific inhibitory PMCA/calcineurin interaction. In result, higher endogenous calcineurin (CaN) activity leads to hypophosphorylation of GAP43 in PMCA2- or PMCA3-deficient lines and intensification of GAP43/CaM complex formation, thus potentially limiting the availability of free CaM. In overall, our results indicate that both "fast” PMCA isoforms could actively regulate the local CaN function and CaN-downstream processes. In connection with our previous observations, we also suggest a negative feedback of cooperative action of CaM, GAP43, and CaN on P/Q and L-type channels activity. PMCAs- and CaN-dependent mechanism presented here, may signify a protective action against calcium overload in neuronal cells during aging, as well a potential way for decreasing neuronal cells vulnerability to neurodegenerative insults. The Author(s), 2015 Calmodulin nationallicence GAP43 nationallicence Calcineurin nationallicence Calcium homeostasis nationallicence PC12 cells nationallicence PMCA nationallicence CaM : Calmodulin nationallicence CaN : Calcineurin nationallicence CsA : Cyclosporin A nationallicence GAP43 : Growth-associated protein nationallicence NFAT : Nuclear factor of activated T-cells nationallicence PMCA : Plasma membrane calcium pump nationallicence _2 : PMCA2-down-regulated PC12 cells nationallicence _3 : PMCA3-down-regulated PC12 cells nationallicence VGCCs : Voltage-gated calcium channels nationallicence Boczek Tomasz Department of Molecular Neurochemistry, Medical University of Lodz, 6/8 Mazowiecka Str., 92-215, Lodz, Poland aut Ferenc Bozena Department of Molecular Neurochemistry, Medical University of Lodz, 6/8 Mazowiecka Str., 92-215, Lodz, Poland aut Lisek Malwina Department of Molecular Neurochemistry, Medical University of Lodz, 6/8 Mazowiecka Str., 92-215, Lodz, Poland aut Zylinska Ludmila Department of Molecular Neurochemistry, Medical University of Lodz, 6/8 Mazowiecka Str., 92-215, Lodz, Poland aut Molecular and Cellular Biochemistry Springer US; http://www.springer-ny.com 407/1-2(2015-09-01), 251-262 0300-8177 407:1-2<251 2015 407 11010 https://doi.org/10.1007/s11010-015-2473-4 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s11010-015-2473-4 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Boczek Tomasz Department of Molecular Neurochemistry, Medical University of Lodz, 6/8 Mazowiecka Str., 92-215, Lodz, Poland aut NATIONALLICENCE 700 1- Ferenc Bozena Department of Molecular Neurochemistry, Medical University of Lodz, 6/8 Mazowiecka Str., 92-215, Lodz, Poland aut NATIONALLICENCE 700 1- Lisek Malwina Department of Molecular Neurochemistry, Medical University of Lodz, 6/8 Mazowiecka Str., 92-215, Lodz, Poland aut NATIONALLICENCE 700 1- Zylinska Ludmila Department of Molecular Neurochemistry, Medical University of Lodz, 6/8 Mazowiecka Str., 92-215, Lodz, Poland aut NATIONALLICENCE 773 0- Molecular and Cellular Biochemistry Springer US; http://www.springer-ny.com 407/1-2(2015-09-01), 251-262 0300-8177 407:1-2<251 2015 407 11010