At this timepoint, however, ceftriaxone caused no significant increase in mEPSC frequency, perhaps owing to the mechanism of its action, which involves increasing translation and membrane insertion of EAATs, rather than direct enhancement of existing transporters.
Among the existing transport systems involved in nutrient uptake in E.coli, two major components of the glycerol uptake system are glpT (Glycerol-3-phosphate transporter) and glpK (Glycerol kinase).
We also added cycloheximide 10 min before the cadmium to ensure that we followed the fate of the pre-existing transporter rather than that of newly synthesized material.
GLUT4 content was unaltered after 1 h exposure of isolated skeletal muscle to spermine NONOate or insulin (data not shown), suggesting spermine NONOate acutely increases glucose transport in muscle by recruiting existing glucose transporters to the cell surface, rather than through GLUT4 biogenesis.
Permeases and transporters existing in XH031T might help the strain to uptake nutrients in the intricate ecologic niche of the deep-sea sediment.
Indeed, two transporters existing in the HL-60 cell line would support our finding that Ant 4 cannot inhibit the uptake of spermidine and spermine.
Alcock et al. presented an opposed view (the "insider's" view), implying that mitochondrial and plastid protein translocation machineries would have been mostly derived from existing endosymbiont bacterial transporters.
Similarly, the majority of solute permeases in the IM of plastids are derived from the host chromosome, in this case by another pathway: duplication of genes encoding existing vacuolar or plasma membrane transporters and the co-option of paralogs for plastid functions [ 45].
However, some aspects of this picture need to be further investigated, since the relationships existing between the accumulation of sulfate transporter mRNAs and the levels of the signal-intermediates do not always appear to be evident [ 9, 17].
Although the low sequence similarity existing between CAN nucleases and ABC transporters does not allow any definite conclusions to be drawn about their potentially analogous functions, it might indicate their putative phylogenetic relationships.
Instead, the intestinal K and L-cells may sense changes in glucose level through existing glucose-sensitive pathways, such as glucokinase and glucose transporter II, which ultimately promote insulin secretion into the medium but not gene expression.
