Adaptive enhancement of cystine and glutamate uptake in human diploid fibroblasts in culture
| Autor: | Shiro Bannai, Emi Kitamura |
|---|---|
| Rok vydání: | 1982 |
| Předmět: |
Adult
Cystine Glutamic Acid Cycloheximide Biology Cell Line Serine chemistry.chemical_compound Glutamates Pregnancy Humans Amino Acids Lung Molecular Biology Cells Cultured Skin Glutamate receptor Biological Transport Cell Biology Glutamic acid Glutathione Fibroblasts Embryo Mammalian Diploidy Kinetics chemistry Biochemistry Glycine Female Intracellular |
| Zdroj: | Biochimica et Biophysica Acta (BBA) - Molecular Cell Research. 721:1-10 |
| ISSN: | 0167-4889 |
| Popis: | The effect of cystine starvation on the transport system of cystine and glutamate was examined in cultures of human diploid fibroblasts. The 2-min uptake of cystine and glutamate increased progressively after a lag of 6 h of cystine starvation. There was approx. 2-3-fold increase, and the increased rate of uptake was accompanied by an increase in the Vmax and unchanged Km. The cystine starvation-induced enhancement appeared specific for the uptake of cystine and glutamate. Actinomycin D or cycloheximide completely blocked the time-related increase in th uptake. Depletion of glutamate did not lead to the enhanced uptake, whereas depletion of glycine and serine caused as much increase in the uptake as depletion of cystine did. The intracellular pool of glutathione was extremely reduced by depletion of cystine, or of glycine and serine, but to a far less extent by depletion of glutamate. The results indicate that te transport system for cystine and glutamate appears to undergo adaptive regulation. It is suggested that glutathione may function as a regulatory signal to this transport system. |
| Databáze: | OpenAIRE |
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