TY - JOUR
T1 - Plasma membrane calcium ATPase-neuroplastin complexes are selectively stabilized in GM1-containing lipid rafts
AU - Ilic, Katarina
AU - Lin, Xiao
AU - Malci, Ayse
AU - Stojanović, Mario
AU - Puljko, Borna
AU - Rožman, Marko
AU - Vukelić, Željka
AU - Heffer, Marija
AU - Montag, Dirk
AU - Schnaar, Ronald L.
AU - Kalanj-Bognar, Svjetlana
AU - Herrera-Molina, Rodrigo
AU - Mlinac-Jerkovic, Kristina
N1 - Publisher Copyright:
© 2021 by the authors. Licensee MDPI, Basel, Switzerland.
PY - 2021/12/1
Y1 - 2021/12/1
N2 - The recent identification of plasma membrane (Ca2+)-ATPase (PMCA)-Neuroplastin (Np) complexes has renewed attention on cell regulation of cytosolic calcium extrusion, which is of particular relevance in neurons. Here, we tested the hypothesis that PMCA-Neuroplastin complexes exist in specific ganglioside-containing rafts, which could affect calcium homeostasis. We analyzed the abundance of all four PMCA paralogs (PMCA1-4) and Neuroplastin isoforms (Np65 and Np55) in lipid rafts and bulk membrane fractions from GM2/GD2 synthase-deficient mouse brains. In these fractions, we found altered distribution of Np65/Np55 and selected PMCA isoforms, namely PMCA1 and 2. Cell surface staining and confocal microscopy identified GM1 as the main complex ganglioside co-localizing with Neuroplastin in cultured hippocampal neurons. Furthermore, blocking GM1 with a specific antibody resulted in delayed calcium restoration of electrically evoked calcium transients in the soma of hippocampal neurons. The content and composition of all ganglioside species were unchanged in Neuroplastin-deficient mouse brains. Therefore, we conclude that altered composition or disorganization of ganglioside-containing rafts results in changed regulation of calcium signals in neurons. We propose that GM1 could be a key sphingolipid for ensuring proper location of the PMCA-Neuroplastin complexes into rafts in order to participate in the regulation of neuronal calcium homeostasis.
AB - The recent identification of plasma membrane (Ca2+)-ATPase (PMCA)-Neuroplastin (Np) complexes has renewed attention on cell regulation of cytosolic calcium extrusion, which is of particular relevance in neurons. Here, we tested the hypothesis that PMCA-Neuroplastin complexes exist in specific ganglioside-containing rafts, which could affect calcium homeostasis. We analyzed the abundance of all four PMCA paralogs (PMCA1-4) and Neuroplastin isoforms (Np65 and Np55) in lipid rafts and bulk membrane fractions from GM2/GD2 synthase-deficient mouse brains. In these fractions, we found altered distribution of Np65/Np55 and selected PMCA isoforms, namely PMCA1 and 2. Cell surface staining and confocal microscopy identified GM1 as the main complex ganglioside co-localizing with Neuroplastin in cultured hippocampal neurons. Furthermore, blocking GM1 with a specific antibody resulted in delayed calcium restoration of electrically evoked calcium transients in the soma of hippocampal neurons. The content and composition of all ganglioside species were unchanged in Neuroplastin-deficient mouse brains. Therefore, we conclude that altered composition or disorganization of ganglioside-containing rafts results in changed regulation of calcium signals in neurons. We propose that GM1 could be a key sphingolipid for ensuring proper location of the PMCA-Neuroplastin complexes into rafts in order to participate in the regulation of neuronal calcium homeostasis.
KW - B4galnt1
KW - GM2/GD2 synthase
KW - Gangliosides
KW - Glycosphingolipids
KW - Membrane microdomains
KW - Neuronal calcium homeostasis
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U2 - 10.3390/ijms222413590
DO - 10.3390/ijms222413590
M3 - Article
C2 - 34948386
AN - SCOPUS:85121295305
SN - 1661-6596
VL - 22
JO - International journal of molecular sciences
JF - International journal of molecular sciences
IS - 24
M1 - 13590
ER -