Publications by authors named "Beate Geist"

Background: Recently, we and others proposed plasticity-related gene 3 (PRG3) as a novel molecule in neuritogenesis based on PRG3 overexpression experiments in neuronal and non-neuronal cell lines. However, direct information on PRG3 effects in neuronal development and, in particular, its putative spatio-temporal distribution and conditions of action, is sparse.

Results: We demonstrate here that PRG3 induces filopodia formation in HEK293 cells depending on its N-glycosylation status.

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Plasticity-related gene 1 (PRG-1) is a novel player in glutamatergic synaptic transmission, acting by interfering with lysophosphatidic acid (LPA)-dependent signaling pathways. In the central nervous system, PRG-1 expression is restricted to postsynaptic dendrites on glutamatergic neurons. In this study, we describe the promoter architecture of the PRG-1 gene using RNA ligase-mediated rapid amplification of cDNA ends (RLM-Race) and PCR analysis.

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Plasticity related gene-1 (PRG-1) is a brain-specific membrane protein related to lipid phosphate phosphatases, which acts in the hippocampus specifically at the excitatory synapse terminating on glutamatergic neurons. Deletion of prg-1 in mice leads to epileptic seizures and augmentation of EPSCs, but not IPSCs. In utero electroporation of PRG-1 into deficient animals revealed that PRG-1 modulates excitation at the synaptic junction.

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This study investigates the impact of intrinsic currents on early neural development. A rat striatal ST14A cell line immortalized by SV40 large T antigen was employed as a model system because these cells act as multipotent neural progenitors when maintained at a permissive temperature of 33 degrees C. The whole-cell patch-clamp, molecular and immunocytochemical experiments point to a unique role of sodium currents in the multipotential stage of neural development.

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Lipid rafts are cholesterol- and shingolipid-enriched membrane microdomains implicated in membrane signaling and trafficking. To assess renal epithelial raft functions through the characterization of their associated membrane proteins, we have isolated lipid rafts from rat kidney by sucrose gradient fractionation after detergent treatment. The low-density fraction was enriched in cholesterol, sphingolipid, and flotillin-1 known as lipid raft markers.

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The Tamm-Horsfall protein (THP; uromodulin), the dominant protein in normal urine, is produced exclusively in the thick ascending limb of Henle's loop. THP mutations are associated with disease; however, the physiological role of THP remains obscure. We generated THP gene-deficient mice (THP -/-) and compared them with wild-type (WT) mice.

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Renal reabsorption of inorganic phosphate is mediated by the type IIa sodium phosphate cotransporter (NaPi-IIa) of the proximal tubule. Changes in renal phosphate handling are mainly attributable to altered NaPi-IIa brush border membrane (BBM) expression. Parathyroid hormone (PTH) induces inactivation of NaPi-IIa by endocytic membrane retrieval and degradation.

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