The activity of the methylgalactoside transport system of E. coli is impaired upon treatment with 3-decynoyl-N-acetylcysteamine, an inhibitor of unsaturated fatty-acid synthesis. Treated cells are unable to be induced for permease activity, while transport sites synthesized before treatment show a regular loss of activity. The inhibition of methylgalactoside transport occurs at a step after tra...

Among the drug delivery and targeting (DDT) routes, lung alveolar epithelium has been given enormous attentions in terms of the delivery of a wide range of macromolecules such as gene- or protein-based nanopharmaceuticals. However, little is known about cellular modulation of lung transport characteristics by endogenous and/or exogenous agents. Thus, in the current study, impact of dexamethason...

Subcellular compartments have unique protein compositions, yet protein synthesis only occurs in the cytosol and in mitochondria and chloroplasts. How do proteins get where they need to go? The first steps are targeting to an organelle and efficient translocation across its limiting membrane. Given that most transport systems are exquisitely substrate specific, how are diverse protein sequences ...

Short term administration of testosterone stimulates net protein synthesis in healthy men. We investigated whether oxandrolone [Oxandrin (OX)], a synthetic analog of testosterone, would improve net muscle protein synthesis and transport of amino acids across the leg. Six healthy men [22+/-1 (+/-SE) yr] were studied in the postabsorptive state before and after 5 days of oral OX (15 mg/day). Musc...

Cycloheximide inhibits polar indoleacetic acid transport in midrib tissues of leaves of citrus (Citrus sinensis [L.] Osbeck) and poplar (Populus deltoides Bartr.) as measured by the donor-receiver agar cylinder technique. It appears that the mechanism of auxin transport inhibition by cycloheximide consists in arresting protein synthesis and not in the disruption of energy flow. The interpretati...

We previously reported that hypotonic stress stimulated transepithelial Na(+) transport via a pathway dependent on protein tyrosine kinase (PTK; Niisato N, Van Driessche W, Liu M, Marunaka Y. J Membr Biol 175: 63-77, 2000). However, it is still unknown what type of PTK mediates this stimulation. In the present study, we investigated the role of receptor tyrosine kinase (RTK) in the hypotonic st...

BACKGROUND In phenylketonuria (PKU), elevated blood phenylalanine (Phe) concentrations are considered to impair transport of large neutral amino acids (LNAAs) from blood to brain. This impairment is believed to underlie cognitive deficits in PKU via different mechanisms, including reduced cerebral protein synthesis. In this study, we investigated the hypothesis that impaired LNAA influx relates...

phosphate (p) is one of the key substrates in energy metabolism and biosynthesis of nucleic acids and membranes. in order to identify molecular mechanisms involved in rice adaptation to p deficiency, we applied a proteomic approach to compare a rice parental line, nipponbare (sensitive), and its near isogenic line (nil6-4) (resistant). the experiment was conducted using a completely randomized ...

Aldosterone, the major sodium retaining hormone in man, will stimulate active transport of sodium across the urinary bladder of the toad, Bufo marinus in vitro, at physiological concentrations of the hormone. The in vitro action of aldosterone is mimicked by steroid hormones with known mineralocorticoid proper­ ties and it is competitively inhibited by other analogues, e.g. spironolactone and c...