The mitochondrial phosphate transport protein (PTP) has been purified in a reconstitutively active form from Saccharomyces cerevisiae and Candidaparapsilosis. ADP/ATP carriers that copurify have been identified. The PTP from S. cerevisiae migrates as a single band (35 kDa) in sodium dodecyl sulfate gels with the same mobility as the N-ethylmaleimide-alkylated beef heart PTP. It does not cross-r...

The discovery of phosphate (Pi) transporter genes has provided a basis for the molecular study of the complex pattern of Pi transport in plants. Over the past two years, a significant amount of information has been generated on the molecular regulation of phosphate transport in plants. Recent developments in plant genomics will soon allow the complete dissection of the signal transduction pathw...

ATP, which is present in the extracellular matrix of multicellular organisms and in the extracellular fluid of unicellular organisms, has been shown to function as a signaling molecule in animals. The concentration of extracellular ATP (xATP) is known to be functionally modulated in part by ectoapyrases, membrane-associated proteins that cleave the gamma- and beta-phosphates on xATP. We present...

The Escherichia coli uhp T gene encodes an active transport system for sugar phosphates. When the uhp T gene was carried on a multicopy plasmid, amplified levels of transport activity occurred, and growth of these strains was inhibited upon the addition of various sugar phosphates. Two different mechanisms for this growth inhibition were distinguished. Exposure to glucose-6-phosphate, fructose-...

The present experiments were designed to detail factors regulating phosphate transport in cultured mouse proximal tubule cells by determining the response to parathyroid hormone (PTH), dopamine, and second messenger agonists and inhibitors. Both PTH and dopamine inhibited phosphate transport by over 30%. The inhibitory effect of PTH was completely abolished in the presence of chelerythrine, a P...

The steady state kinetics of sodium and potassium ion transport adenosine triphosphatase (EC 3.6-l. 3) suggests an activating action of adenosine triphosphate in addition to its action as a phosphate donor. This action might be an acceleration of dissociation of Kf or its congeners from the enzyme. To test this possibility transient kinetics of the phosphoenzyme was investigated. In membranes f...

Reconstitution of phosphate transport in Escherichia coli was demonstrated. Conversion of E. coli K10 cells to spheroplasts decreased phosphate transport to about 2%. Addition of purified phosphate-binding protein at physiological levels to these spheroplasts caused a mean 14-fold increase in phosphate transport rate. Crude shock fluid fractions were also stimulatory but not if the shock fluid ...

The movement of auxin in the basipetal and acropetal directions is compared for 4 types of tissue. It is observed that the transport may proceed in either a linear or a non-linear manner with time. The polarity of transport through any given type of tissue increases exponentially with increasing lengths of tissue traversed, suggesting that the polarity of transport is developed as a consequence...