Abstract: The present invention provides several modified ABC transporter polypeptides that exhibit novel localization in the plasma membrane of polarized and non-polarized cells. The modified ABC transporter of the invention comprises the amino acid sequence of a native apically targeted ABC transporter, in particular cMOAT, MDR3 or MRP4, wherein the terminal tripeptide T-K-F motif of said native ABC transporter is mutated. The isolated modified ABC transporter polypeptide of the invention, and the nucleotide sequence encoding said polypeptide, have utility in the following applications: First, they are used to induce a drug resistant phenotype in a cell. Second, they are used to protect non-polarized cells during chemotherapy and other therapeutic applications. Third, they are used to produce novel cell lines that are used to screen for novel agonists or antagonists of the corresponding native ABC transporter polypeptides.

Abstract: Instabilities in the output voltage provided from an AC power supply system connected to a power factor correcting load are suppressed by a stabilizer which is connected across the output lines from the power supply system to the load. The stabilizing apparatus includes a rectifier having AC input nodes connected to the power supply system output lines, and DC output nodes at which DC voltage appears. A capacitor and resistor are connected in parallel across the output nodes of the rectifier. During normal operation, where the peak AC voltage from the power supply system is substantially constant, the capacitor charges up to a voltage level near the zero to peak value of the AC voltage waveform, with the charge on the capacitor slowly dissipated through the parallel resistor at a rate that does not substantially dissipate the charge between peaks of the AC voltage waveform.