| Abstract: |
Glucose is fundamental to the metabolism and survival of mammalian cells, and its passage across cell membranes is mediated by a family of transport proteins (glucose transporters) located at the cell membrane. We studied the regulation of glucose transport by granulocyte-macrophage colony-stimulating factor (GM-CSF), a hemopoietin that functions in regulating the proliferation, differentiation, maturation and survival of cells of the host defense system. The receptor for GM-CSF is composed of an α and β subunit, and the α-β complex binds GM-CSF with high affinity whereas tbe isolated α subunit binds GM-CSF with low affinity. Using Xenopus laevis oocytes expressing the human GM-CSF receptor α subunit, we provided direct evidence indicating that the isolated α subunit signals for increased glucose uptake in a phosphorylation-independent manner. We extended these studies to human neutrophils and HL-60 cells and found that signaling for hexose uptake also occurs in a phosphorylation-independent manner in cells expressing the high-affinity GM-CSF receptor. Since the glucose transporters are multifunctional transport proteins, the findings regarding GM-CSF regulation of cellular glucose uptake may have wide import relative to CSF regulation of molecular transport in target cells. |
| Keywords: |
signal transduction; human cell; nonhuman; conference paper; animal cell; oocyte; animal; oocytes; gene expression; models, biological; granulocyte macrophage colony stimulating factor; cell line; phosphorylation; isoflavones; neutrophil; cell membrane; neutrophils; glucose; glucose transport; in vitro; xenopus laevis; gm-csf; genistein; granulocyte-macrophage colony-stimulating factor; glucose transporter; deoxyglucose; biological transport, active; cell strain hl 60; receptors, granulocyte-macrophage colony-stimulating factor; frog; receptor subunit; protein-tyrosine kinase; colony stimulating factor receptor; monosaccharide transport proteins; human; female; support, u.s. gov't, p.h.s.; csf receptors; glucose transport system
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