Christine Bessia

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A putative chemokine receptor that we previously cloned and termed LESTR has recently been shown to function as a co-receptor (termed fusin) for lymphocyte-tropic HIV-1 strains. Cells expressing CD4 became permissive to infection with T-cell-line-adapted HIV-1 strains of the syncytium-inducing phenotype after transfection with LESTR/fusin complementary DNA.(More)
The Notch1 receptor is presented at the cell membrane as a heterodimer after constitutive processing by a furin-like convertase. Ligand binding induces the proteolytic release of Notch intracellular domain by a gamma-secretase-like activity. This domain translocates to the nucleus and interacts with the DNA-binding protein CSL, resulting in transcriptional(More)
The Notch receptor, which is involved in numerous cell fate decisions in invertebrates and vertebrates, is synthesized as a 300-kDa precursor molecule (p300). We show here that proteolytic processing of p300 is an essential step in the formation of the biologically active receptor because only the cleaved fragments are present at the cell surface. Our(More)
The molecular basis of X-linked recessive anhidrotic ectodermal dysplasia with immunodeficiency (EDA-ID) has remained elusive. Here we report hypomorphic mutations in the gene IKBKG in 12 males with EDA-ID from 8 kindreds, and 2 patients with a related and hitherto unrecognized syndrome of EDA-ID with osteopetrosis and lymphoedema (OL-EDA-ID). Mutations in(More)
We have characterized a flat cellular variant of HTLV-1 Tax-transformed rat fibroblasts, 5R, which is unresponsive to all tested NF-kappaB activating stimuli, and we report here its genetic complementation. The recovered full-length cDNA encodes a 48 kDa protein, NEMO (NF-kappaB Essential MOdulator), which contains a putative leucine zipper motif. This(More)
active NF-␬B is released and translocated to the nucleus as a result of the proteolytic degradation of I␬B proteins. Phosphorylation of I␬B␣ on Ser-32 and Ser-36 targets the molecule for degradation by the ubiquitin-26S pro-teasome pathway. While the processes leading to the degradation of the I␬B proteins are relatively well under-de l'Expression Gé nique(More)
Human cytomegalovirus (CMV) infection can elicit a transitory, but profound, immunodepression in immunocompetent individuals. Cytopathogenic destruction of CMV-infected leukocytes alone does not seem sufficient to explain this phenomenon, which suggests that immune system mediators (cytokines) may play a role in amplifying local modifications wrought by CMV(More)
The X protein of hepatitis B virus (HBV) is a transcriptional activator which is required for infection and may play an important role in HBV-associated hepatocarcinogenesis. It has been suggested that X acts as a nuclear coactivator or stimulates several signal transduction pathways by acting in the cytoplasm. One of these pathways leads to the nuclear(More)
The mechanism by which TCR signaling activates NF-kappaB is poorly understood. We demonstrate here that the IKK kinase complex is recruited to the immunological synapse and can be coprecipitated with the TCR after T cell activation. Using ZAP-70-deficient T cells expressing a hybrid molecule between the SH2 domain of ZAP-70 and NEMO/IKKgamma, we showed that(More)
The human cytomegalovirus (HCMV) open reading frame UL83 encodes a phosphoprotein of 64 to 68kDa (pp65) which is a major constituent of this virion and dense bodies. To determine the importance of the HCMV gene in the virus cycle, we studied HCMV replication in astrocytoma cells stably transfected with a retroviral vector carrying an antisense UL83 cDNA.(More)