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Eukaryotic initiation factor 5A(eIF-5A) is a cellular cofactor require d for the function of the human immunodeficiency virus type-1 (HIV-1) Rev trans-activator protein. The majority of a set of eIF-5A mutants did not support growth of yeast cells having an inactivated genomic copy of eIF-5A, indicating that the introduced mutation eliminated eIF-5A(More)
Sphingosine kinase has been recognized as an essential signaling molecule that mediates the intracellular conversion of sphingosine to sphingosine-1-phosphate. In mast cells, induction of sphingosine kinase and generation of sphingosine-1-phosphate have been linked to the initial rise in Ca(2+), released from internal stores, and to degranulation. These(More)
Posttranslational modification of a specific lysine residue in eukaryotic initiation factor 5A (eIF-5A) is essential for cell viability and proliferation. The product of this modification is hypusine, an amino acid unique to eIF-5A. We have purified and characterized one major and three minor isoforms of human eIF-5A from HeLa cells. The main form, which(More)
A small number of signaling cascades represented by mitogen-activated protein kinases, phosphoinositol-3-kinase, protein kinase C, signal transducers and activators of transcription, Ca2+/calcineurin, and a few other molecules are linked to an incomparably large number of surface receptors. Parallel activation of several of these pathways and the existence(More)
The N-terminus of ceramide kinase (CERK) is thought to be myristoylated and to contain a pleckstrin homology (PH) domain. We found that deletion of this region (DeltaPH-CERK) ablates activity. This is not due to prevention of N-terminal myristoylation since a G2A CERK mutant, which cannot be myristoylated, was active. CERK was able to bind liposomes, as(More)
Cap 'n' collar-basic leucine zipper (CNC-bZIP) proteins are widely implicated in developmental processes throughout different species. Evidence is accumulating that some of them are also participating in induced gene expression in the adult. Here we show that the three CNC-bZIP members NF-E2, Nrf1 and Nrf2 are constitutively expressed in the murine mast(More)
Common signaling chains of various receptor families, despite some similarities, are able to provoke quite different cellular responses. This suggests that they are linked to different cascades and transcription factors, dependent on the context of the ligand binding moiety and the cell type. The ITAM (immunoreceptor tyrosine-based activation motif)(More)
The transcription factor nuclear factor of activated T-cells (NF-AT) plays an essential role in the activation of many early immune response genes. A dynamic equilibrium between calcineurin and cellular kinases controls its phosphorylation and thus regulates its activity by determining its subcellular localization. Here, we demonstrate that T-cell(More)
Over the last few years, sphingolipids have been identified as potent second messenger molecules modulating cell growth and activation. A newly emerging facet to this class of lipids suggests a picture where the balance between two counterregulatory lipids (as shown in the particular example of ceramide and sphingosine-1-phosphate in T lymphocyte apoptosis)(More)
Over the last few years, sphingolipids have been identified as potent second messenger molecules modulating cell growth and activation. A newly emerging facet to this class of lipids suggests a picture where the balance between two counterregulatory lipids (as shown in the particular example of ceramide and sphingosine-1-phosphate in T lymphocyte apoptosis)(More)