The mammalian gastrointestinal tract and bloodstream are highly disparate biological niches that differ in concentrations of nutrients such as iron. However, some commensal-pathogenic microorganisms, such as the yeast Candida albicans, thrive in both environments. We report the evolution of a transcription circuit in C. albicans that controls iron uptake and determines its fitness in both niche...

Recent studies showed that gallium and iron uptake are decreased in gallium-resistant (R) CCRF-CEM cells; however, the mechanisms involved were not fully elucidated. In the present study, we compared the cellular uptake of 59Fe-transferrin (Tf) and 59Fe-pyridoxal isonicotinoyl hydrazone (PIH) to determine whether the decrease in iron uptake by R cells is caused by changes in Tf receptor (TfR)-d...

Iron transferrin, the highly stable carrier of plasma iron, may be dissociated, under physiological conditions, by sodium thioglycollate, a reaction which involves the formation of iron thioglycollate complexes. This suggested that sulphydryl radicals, which are the active groups in thioglycollate and related compounds, may play a part in the uptake of iron by immature red cells from iron trans...

Iron delivery to mammalian cells is traditionally ascribed to diferric transferrin (Tf). We recently reported that human erythroid precursor cells possess specific membranes receptors that bind and internalize acid isoferritin. Here we show that ferritin uptake by these cells is highly regulated and that the internalized ferritin-iron is used for home synthesis and thus, this process could cons...

plant growth promoting rhizobacteria and arbuscular mycorrhizal fungi can inhanced plant growth by increasing nutrient uptake. in order to investigate the effect of pgpr and amf on some morphological parameters, macro (nitrogen, phosphorus, potassium, calcium and magnesium) and micro (iron, zinc and copper) nutrients uptake, percentage of root colonization and some morphological factors of pepp...

The coastal diatom Thalassiosira weissfogii responds to iron limitation with decreasing growth rate, decreasing quotas of cellular iron, and increasing rates of maximum short term uptake. Growth response to steady iron limitation can be modeled according to the equations of Droop and Monod. The cellular iron quota varies from about 2 to 25 x 1O-5 mol iron per liter-cell with increasing iron; th...

Separate pathways for transport of nontransferrin ferric and ferrous iron into tissue cultured cells were demonstrated. Neither the ferric nor ferrous pathway was shared with either zinc or copper. Manganese shared the ferrous pathway but had no effect on cellular uptake of ferric iron. We postulate that ferric iron was transported into cells via beta(3)-integrin and mobilferrin (IMP), whereas ...

1. The effect of iron chelators on iron uptake, ferritin and total protein synthesis was studied in cultured Chang cells. Desferrioxamine depressed ferritin synthesis and completely inhibited iron uptake by ferritin protein. Rhodotorulic acid reduced iron uptake by the cells but had little effect on ferritin synthesis. Diethylenetriamine pentaacetic acid produced complete inhibition of iron upt...

A family of four putative transporters (Arn1p–4p) in Saccharomyces cerevisiae is expressed under conditions of iron deprivation and is regulated by Aft1p, the major iron-dependent transcription factor in yeast. One of these, Arn3p/Sit1p, facilitates the uptake of ferrioxamine B, a siderophore of the hydroxamate class. Here we report that ARN family members facilitated the uptake of iron from th...

To fulfill their nutritional requirement for iron, bacteria utilize various iron sources which include the host proteins transferrin and lactoferrin, heme, and low molecular weight iron chelators termed siderophores. The iron sources are transported into the Gram-negative bacterial cell via specific uptake pathways which include an outer membrane receptor, a periplasmic binding protein (PBP), a...