Abstract
Galectin-mediated ligation of glycoepitopes on T-cell activation markers induces an increase in the cytosolic calcium concentration ([Ca(2+)](i)) originating from a transient Ca(2+) release of internal stores as well as a sustained influx across the plasma membrane. In transiently transfected Jurkat T-lymphocytes, galectins [galectin-1 (gal-1), recombinant human galectin-1 (rec gal-1), nematode 32-kDa galectin (LEC-1), nematode 16-kDa galectin (LEC-6)] differentially stimulate the expression of the luciferase reporter gene constructs pNFAT-TA-Luc and pAP1(PMA)-TA-Luc, which are activated by the nuclear factor of activated T-cells (NFAT) or the transcription factor, activator protein 1 (AP-1), respectively. The galectin-stimulated expression of the reporter constructs is completely inhibited by lactose (30 mM) and asialofetuin (30 microM) carrying Galbeta1-4GlcNAc sequences. Preincubation of pNFAT-TA-Luc-transfected cells with cyclosporine A (0.1 microM) and FK506 (0.01 microM) abrogated the gal-1-induced expression of the reporter luciferase (Luc). Electrophoretic mobility shift assays (EMSAs) provided evidence for gal-1-stimulated increase in the binding of nuclear extracts to a synthetic oligonucleotide with an AP-1 consensus sequence.
Copyright 2002 Elsevier Science Inc.
MeSH terms
-
Asialoglycoproteins / pharmacology
-
Binding Sites / drug effects
-
Binding Sites / genetics
-
Binding Sites / immunology
-
Calcium Signaling / drug effects
-
Calcium Signaling / genetics
-
Calcium Signaling / immunology*
-
Cell Membrane / drug effects
-
Cell Membrane / immunology*
-
Cell Membrane / metabolism
-
Cyclosporine / pharmacology
-
Cytosol / drug effects
-
Cytosol / immunology*
-
Cytosol / metabolism
-
DNA-Binding Proteins / genetics
-
DNA-Binding Proteins / metabolism*
-
Female
-
Fetuins
-
Galectin 1 / genetics
-
Galectin 1 / immunology*
-
Galectin 1 / metabolism
-
Gene Expression Regulation / drug effects
-
Gene Expression Regulation / immunology
-
Genes, Reporter / genetics
-
Genes, Reporter / immunology
-
Humans
-
Jurkat Cells
-
Lactose / pharmacology
-
Lymphocyte Activation / drug effects
-
Lymphocyte Activation / immunology*
-
NFATC Transcription Factors
-
Nuclear Proteins*
-
Oligonucleotide Probes
-
Pancreatitis-Associated Proteins
-
Recombinant Fusion Proteins / genetics
-
Recombinant Fusion Proteins / immunology
-
Recombinant Fusion Proteins / metabolism
-
T-Lymphocytes / drug effects
-
T-Lymphocytes / immunology*
-
T-Lymphocytes / metabolism
-
Tacrolimus / pharmacology
-
Transcription Factor AP-1 / genetics
-
Transcription Factor AP-1 / immunology
-
Transcription Factor AP-1 / metabolism
-
Transcription Factors / genetics
-
Transcription Factors / metabolism*
-
alpha-Fetoproteins / pharmacology
Substances
-
Asialoglycoproteins
-
DNA-Binding Proteins
-
Fetuins
-
Galectin 1
-
NFATC Transcription Factors
-
Nuclear Proteins
-
Oligonucleotide Probes
-
Pancreatitis-Associated Proteins
-
REG3A protein, human
-
Recombinant Fusion Proteins
-
Transcription Factor AP-1
-
Transcription Factors
-
alpha-Fetoproteins
-
asialofetuin
-
Cyclosporine
-
Lactose
-
Tacrolimus