0000000000253216
AUTHOR
Gerald Seifert
showing 5 related works from this author
Gray Matter NG2 Cells Display Multiple Ca2+-Signaling Pathways and Highly Motile Processes
2011
NG2 cells, the fourth type of glia in the mammalian CNS, receive synaptic input from neurons. The function of this innervation is unknown yet. Postsynaptic changes in intracellular Ca(2+)-concentration ([Ca(2+)](i)) might be a possible consequence. We employed transgenic mice with fluorescently labeled NG2 cells to address this issue. To identify Ca(2+)-signaling pathways we combined patch-clamp recordings, Ca(2+)-imaging, mRNA-transcript analysis and focal pressure-application of various substances to identified NG2-cells in acute hippocampal slices. We show that activation of voltage-gated Ca(2+)-channels, Ca(2+)-permeable AMPA-receptors, and group I metabotropic glutamate-receptors provo…
NG2-expressing cells in the nervous system revealed by the NG2-EYFP-knockin mouse.
2008
The NG2 glycoprotein is a type I membrane protein expressed by immature cells in the developing and adult mouse. NG2+ cells of the embryonic and adult brain have been principally viewed as oligodendrocyte precursor cells but have additionally been considered a fourth glial class. They are likely to be a heterogeneous population. In order to facilitate studies on the function of NG2+ cells and to characterize these cells in situ, we generated an enhanced yellow fluorescent protein (EYFP) “knockin mouse.” EYFP-expressing cells in heterozygous knockin mice expressed the NG2 protein in all regions and at all ages studied. The EYFP+ cells did not express markers of mature glia, developing or mat…
The NG2 Protein Is Not Required for Glutamatergic Neuron-NG2 Cell Synaptic Signaling.
2014
NG2 glial cells (as from now NG2 cells) are unique in receiving synaptic input from neurons. However, the components regulating formation and maintenance of these neuron–glia synapses remain elusive. The transmembrane protein NG2 has been considered a potential mediator of synapse formation and alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR) clustering, because it contains 2 extracellular Laminin G/Neurexin/Sex Hormone-Binding Globulin domains, which in neurons are crucial for formation of transsynaptic neuroligin– neurexin complexes. NG2 is connected via Glutamate Receptor-Interacting Protein with GluA2/3-containing AMPARs, thereby possibly mediating receptor clus…
Modulation of voltage-gated K(+) channels Kv11 and Kv1 4 by forskolin.
2002
Forskolin (FSK) affects voltage-gated K + (Kv) currents in different cell types, but it is not known which of the various subunits form FSK-sensitive Kv channels. We compared the effect of the compound at Kv1.1 and Kv1.4 channels ectopically expressed in HEK 293 cells. Low FSK concentrations induced a phosphorylation-dependent potentiation of Kv1.1 currents. At higher concentrations, this effect was superimposed by a fast, cAMP-independent channel block. Kv1.4 currents were inhibited with lower potency by FSK but were not modified by phosphorylation. The variable effect of the compound might help to distinguish between Kv subunits expressed by native cells. 2002 Elsevier Science Ltd. All …
Analysis of phosphorylation-dependent modulation of Kv1.1 potassium channels.
2003
The voltage-gated potassium channel Kv1.1 contains phosphorylation sites for protein kinase A (PKA) and protein kinase C (PKC). To study Kv1.1 protein expression and cellular distribution in regard to its level of phosphorylation, the effects of PKA and PKC activation on Kv1.1 were investigated in HEK 293 cells stably transfected with Kv1.1 (HEK 293/1). Without kinase activation, HEK 293/1 cells carry unphosphorylated Kv1.1 protein in the plasma membranes, whereas large amounts of phosphorylated and unphosphorylated Kv1.1 protein were located intracellularly. Activation of PKA resulted in phosphorylation of intracellular Kv1.1 protein, followed by a rapid translocation of Kv1.1 into the pla…