Amino acid depletion activates TonEBP and sodium-coupled inositol transport
Cited 21 times inCited 22 times in
- Amino acid depletion activates TonEBP and sodium-coupled inositol transport
- Franchi-Gazzola, R; Visigalli, R; Dall'Asta, V; Sala, R; Woo, SK; Kwon, H. Moo; Gazzola, GC; Bussolati, O
- Cell volume; Glutamine; Hypertonic stress; Stress proteins; System A; Tonicity-responsive enhancer-binding protein
- Issue Date
- AMER PHYSIOLOGICAL SOC
- AMERICAN JOURNAL OF PHYSIOLOGY-CELL PHYSIOLOGY, v.280, no.6, pp.C1465 - C1474
- The expression of the osmosensitive sodium/myo-inositol cotransporter (SMIT) is regulated by multiple tonicity-responsive enhancers (TonEs) in the 5'-flanking region of the gene. In response to hypertonicity, the nuclear abundance of the transcription factor TonE-binding protein (TonEBP) is increased, and the transcription of the SMIT gene is induced. Transport system A for neutral amino acids, another osmosensitive mechanism, is progressively stimulated if amino acid substrates are not present in the extracellular compartment. Under this condition, as in hypertonicity, cells shrink and mitogen-activated protein kinases are activated. We demonstrate here that a clear-cut nuclear redistribution of TonEBP, followed by SMIT expression increase and inositol transport activation, is observed after incubation of cultured human fibroblasts in Earle's balanced salts (EBSS), an isotonic, amino acid-free saline. EBSS-induced SMIT stimulation is prevented by substrates of system A, although these compounds do not compete with inositol for transport through SMIT. We conclude that the incubation in isotonic, amino acid-free saline triggers an osmotic stimulus and elicits TonEBP-dependent responses like hypertonic treatment.
- ; Go to Link
Appears in Collections:
- SLS_Journal Papers
can give you direct access to the published full text of this article. (UNISTARs only)
Show full item record
Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.