About
72
Publications
11,245
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
2,497
Citations
Citations since 2017
Introduction
Additional affiliations
Education
September 1994 - June 1999
Publications
Publications (72)
Development is orchestrated through a complex interplay of multiple transcription factors. The comprehension of this interplay will help us to understand developmental processes. Here we analyze the relationship between two key transcription factors: CBX4, a member of the Polycomb Repressive Complex 1 (PRC1), and SALL1, a member of the Spalt-like f...
Interleukin (IL)-6 is a pleiotropic cytokine involved in the regulation of hematological and immune responses. IL-6 is secreted chiefly by stromal cells, but little is known about its precise role in the homeostasis of human mesenchymal stromal cells (hMSCs) and the role it may play in hMSC-mediated immunoregulation. We studied the role of IL-6 in...
DNA damage activated by Adriamycin (ADR) promotes ubiquitin–proteasome system-mediated proteolysis by stimulating both the activity of ubiquitylating enzymes and the proteasome. In ADR-resistant breast cancer MCF7 (MCF7ADR) cells, protein ubiquitylation is significantly reduced compared to the parental MCF7 cells. Here, we used tandem ubiquitin-bin...
TRAF2 dependent K63-polyubiquitinations have been recently shown to connect CD137 (4-1BB) stimulation to NF-κB activation. In a search of deubiquitinase enzymes (DUBs) that could regulate such a signaling route, A20 and CYLD were found to coimmunoprecipitate with CD137 and TRAF2 complexes. Indeed, overexpression of A20 or CYLD downregulated CD137-e...
γδ T cells play a role in a wide range of diseases such as autoimmunity and cancer. The majority of circulating human γδ T lymphocytes express a Vγ9Vδ2+ (Vδ2+) T cell receptor (TCR) and following activation release pro-inflammatory cytokines. In this study, we show that IFNγ, produced by Vδ2+ cells, activates mesenchymal stem cell (MSC)-mediated im...
Total PBMCs were activated and cultured in the presence or absence of MSCs.
Addition of 1-MT alone reduces significantly the expansion of Vδ2+ cells even in the absence of MSCs while addition of vehicle has no influence on the percentage of Vδ2+ cells. Results show the means ± S.D. of triplicate samples.
(TIF)
Background
Mutations in leucine-rich repeat kinase 2 (LRRK2) contribute to both familial and idiopathic forms of Parkinson’s disease (PD). Neuroinflammation is a key event in neurodegeneration and aging, and there is mounting evidence of LRRK2 involvement in inflammatory pathways. In a previous study, we described an alteration of the inflammatory...
The matrix protein of Ebola virus (EBOV) VP40 regulates viral budding, nucleocapsid recruitment, virus structure and stability, viral genome replication and transcription, and has an intrinsic ability to form virus-like particles. The elucidation of the regulation of VP40 functions is essential to identify mechanisms to inhibit viral replication an...
SUMO-interacting motifs (SIMs) recognize SUMOylated proteins with high specificity allowing to connect SUMO-modified proteins. Multiple SIMs fused to distinct tags have been used to increase their affinity and generate more efficient purification tools. Enrichment of SUMOylated proteins using SIMs arranged in tandem (SUMO-traps) facilitates the ide...
Analyzing protein ubiquitylation changes during physiological or pathological processes is challenging due to its high reversibility and dynamic turnover of modified targets. We have developed a protein microarray to assess endogenous ubiquitylation levels from cell cultures, employing Tandem Ubiquitin Binding Entities (TUBEs) with 3 or 4 UBA domai...
CD137 (4-1BB, TNF-receptor superfamily 9) is a surface glycoprotein of the TNFR family which can be induced on a variety of leukocyte subsets. On T cells and NK cells, CD137 is expressed following activation and, if ligated by its natural ligand (CD137L), conveys polyubiquitination-mediated signals via TRAF-2 that inhibit apoptosis, while enhancing...
SUMOylation, the covalent binding of Small Ubiquitin-like Modifier (SUMO) to target proteins, is a posttranslational modification
that regulates critical cellular processes in eukaryotes. In insects, SUMOylation has been studied in holometabolous species,
particularly in the dipteran Drosophila melanogaster, which contains a single SUMO gene (smt3)...
Class IA phosphatidylinositol 3-kinases (PI3Ks) are composed of p110 catalytic and p85 regulatory subunits. How regulatory subunits modulate PI3K activity remains only partially understood. Here we identified SUMO (small ubiquitin-related modifier) as a new player modulating this regulation. We demonstrate that both p85β and p85α are conjugated to...
Tumor suppressor p53 plays a crucial antiviral role and targeting of p53 by viral proteins is a common mechanism involved in virus oncogenesis. The activity of p53 is tightly regulated at the post-translational levels through a myriad of modifications. Among them, modification of p53 by SUMO has been associated with the onset of cellular senescence...
The Ubiquitin-Proteasome System (UPS) plays an important role in the setting of the cellular response to multiple stress signals. Although the primary function of ubiquitin was initially associated with proteolysis, it is now considered as a key regulator of protein function controlling, among other functions, signalling cascades, transcription, ap...
Accurate regulation of nuclear factor-jB (NF-jB) activity is crucial to prevent a variety of disorders including immune and inflammatory diseases. Active NF-jB promotes IjBa and A20 expression, important negative regulatory molecules that control the NF-jB response. In this study, using two-hybrid screening we identify the RING-type zinc-finger pro...
Accurate regulation of nuclear factor-κB (NF-κB) activity is crucial to prevent a variety of disorders including immune and inflammatory diseases. Active NF-κB promotes IκBα and A20 expression, important negative regulatory molecules that control the NF-κB response. In this study, using two-hybrid screening we identify the RING-type zinc-finger pro...
The dsRNA-dependent kinase PKR is an interferon-inducible protein with ability to phosphorylate the α subunit of the eukaryotic
initiation factor (eIF)-2 complex, resulting in a shut-off of general translation, induction of apoptosis, and inhibition
of virus replication. Here we analyzed the modification of PKR by the small ubiquitin-like modifiers...
The tumor suppressor p53 regulates the expression of genes involved in cell cycle progression, senescence and apoptosis. Here, we investigated the effect of single point mutations in the oligomerization domain (OD) on tetramerization, transcription, ubiquitylation and stability of p53. As predicted by docking and molecular dynamics simulations, p53...
Serine threonine kinase AKT has a central role in the cell, controlling survival, proliferation, metabolism and angiogenesis. Deregulation of its activity underlies a wide range of pathological situations, including cancer. Here we show that AKT is post-translationally modified by the small ubiquitin-like modifier (SUMO) protein. Interestingly, nei...
Although mesenchymal stromal cells (MSCs) possess the capacity to modulate immune responses, little is known about the mechanisms that underpin these processes. In this study, we show that immunosupression is mediated by activation of nuclear factor kappa B (NF-κB) in human MSCs. This pathway is activated by TNF-α that is generated following TCR st...
The tumor suppressor p53 regulates the expression of genes involved in cell cycle progression, senescence and apoptosis. Here, we investigated the effect of single point mutations in the oligomerization domain (OD) on tetramerization, transcription, ubiquitylation and stability of p53. As predicted by docking and molecular dynamics simulations, p53...
The zinc-finger protein A20 is a key player in the negative feedback regulation of the nuclear factor kappa-light-chain-enhancer of activated B-cell (NF-κB) pathway in response to multiple stimuli. Tumor necrosis factor alpha (TNFα), a cytokine with pleiotropic effects on cellular proliferation and differentiation, dramatically increases A20 expres...
There is growing evidence that many host proteins involved in innate and intrinsic immunity are regulated by SUMOylation, and that SUMO contributes to the regulatory process that governs the initiation of the type I interferon (IFN) response. The tumor suppressor p53 is a modulator of the IFN response that plays a role in virus-induced apoptosis an...
SUMO-modified proteins are recognized by SUMO interacting motifs (SIMs), thus triggering diverse cellular responses. Here SIMs were used to develop SUMO-traps to capture endogenous SUMOylated proteins. Our results show that these small peptides are transferable motifs that maintain their SUMO binding capacity when fused to the heterologous carrier...
Supplementary Information
The NF-kB pathway is regulated by SUMOylation at least at three levels: the inhibitory molecule IkBa, the IKK subunit c/ NEMO and the p52 precursor p100. Here we investigate the role of SUMO-2/3 in the degradation of IkBa and activation of NF-kB mediated by TNFa. We found that under conditions of deficient SUMOylation, an important delay in both TN...
SUMOylation contributes to the regulation of many essential cellular factors. Diverse techniques have been used to explore the functional consequences of protein SUMOylation. Most approaches consider the identification of sequences on substrates, adaptors, or receptors regulating the SUMO conjugation, recognition, or deconjugation. The large majori...
Supplementary material include databases of putative and real sumoylated proteins (Table 1), overlapping of datasets of putative and real sumoylated proteins (Table 2), databases of sumoylated peptides (Table 3), molecular functions of putative and real sumoylated proteins (Table 4), canonical pathways of putative and real sumoylated proteins found...
Studying postubiquitylation events has always been a difficult task due to the labile nature of these posttranslational modifications. When utilized in tandem, ubiquitin-binding entities (TUBEs) not only increase up to thousand times the affinity for poly-ubiquitin chains but also protect ubiquitylated proteins from the action of the proteasome and...
Received 9 March 2012; Accepted 12 April 2012Academic Editor: Philip Coffino
SUMOylation contributes to the regulation of many essential cellular factors. Diverse techniques have been used to explore the functional consequences of protein SUMOylation. Most approaches consider the identification of sequences on substrates, adaptors or receptors regulating the SUMO conjugation, recognition or de-conjugation. The large majorit...
TUBE-captured monoubiquitylated IκBα fails to be immunoprecipitated using specific IκBα antibodies. HEK293 cells were treated or not, 1 hour with 20 µM of MG-132 and lysed in a buffer containing 100 µg of TUBE-HR23A or GST proteins. After lysis, samples were centrifuged and clarified supernatant incubated for 2 hours in the presence of glutathione...
Immunoprecipitation using IκBα antibodies fail to pull down monoubiquitylated IκBα. HEK293 cells were treated or not for 1 hour with 20 µM of MG-132, lysed in the properly lysis buffer for 20 minutes, centrifuged and the supernatant was incubated with cross-linked anti- IκBα (10B) antibody for 2 hours. After incubation the samples were centrifuged,...
IκBαWT and ubiquitin-IκBα fusion were expressed in HEK293 cells, and processed for immunostaining with anti-SV5 or anti-HA antibodies.
(TIF)
The NF-κB pathway is regulated by multiple post-translational modifications including phosphorylation, ubiquitylation and SUMOylation. Many of these modifications act on the natural inhibitor IκBα modulating its capacity to control signal-mediated NF-κB activity. While the canonical pathway involving the phosphorylation and polyubiquitylation of Iκ...
In normal cells p53 is maintained at low level through the action of the ubiquitin-proteasome system. As a consequence of p53 transcriptional activity, various regulators of this tumor suppressor are produced, forming a negative feedback loop tightly controlling p53 stability. One of the most prominent is the ubiquitin-ligase Mdm2. Here, we have us...
Post-translational modification with ubiquitin is one of the most important mechanisms in the regulation of protein stability and function. However, the high reversibility of this modification is the main obstacle for the isolation and characterization of ubiquitylated proteins. To overcome this problem, we have developed tandem-repeated ubiquitin-...
Among the several signalling pathways regulated by ubiquitin and ubiquitin-like proteins, the one activating NF-kappaB (nuclear factor kappaB) is certainly one of the best characterized. The regulation of the activity of this transcription factor by members of the ubiquitin family occurs at various levels, imposing overlapping controls of security...
In T cells, the PI3K pathway promotes proliferation and survival induced by Ag or growth factors, in part by inactivating the FOXO transcription factor 1. We now report that FOXO1 controls the expression of L-selectin, an essential homing molecule, in human T lymphocytes. This control is already operational in unprimed T cells and involves a transc...
ICOS ligation in concert with TCR stimulation results in strong PI3K activation in T lymphocytes. The ICOS cytoplasmic tail contains an YMFM motif that binds the p85α subunit of class IA PI3K, similar to the YMNM motif of CD28, suggesting a redundant function of the two receptors in PI3K signaling. However, ICOS costimulation shows greater PI3K act...
ICOS ligation in concert with TCR stimulation results in strong PI3K activation in T lymphocytes. The ICOS cytoplasmic tail contains an YMFM motif that binds the p85alpha subunit of class IA PI3K, similar to the YMNM motif of CD28, suggesting a redundant function of the two receptors in PI3K signaling. However, ICOS costimulation shows greater PI3K...
Human Mesenchymal Stem Cells (hMSC), derived mainly from adult bone marrow, are valuable models for the study of processes involved in stem cell self-renewal and differentiation. As the Extracellular signal-Regulated Kinase (ERK) signalling pathway is a major contributor to cellular growth, differentiation and survival, we have studied the function...
T cell clonal expansion contributing to host defense against pathogens is a tightly controlled process to maintain the homeostasis of the immune system. Our understanding of how T cell growth and proliferation are controlled following antigenic stimulation is therefore a major challenge. Antigen recognition occurs when a naive T lymphocyte contacts...
Numerous cancers are caused by an uncontrolled uncontrolled activity of the PI3-kinase pathway. The proto-oncogene Akt, one of its main effectors, commands several molecular switches involved in cell survival and proliferation. One of these switches is represented by a group of related molecules belonging to the Forkhead family of transcription fac...
We have previously reported at the single cell level that PI3K is activated after conjugate formation between T lymphocytes and APCs. However, in contrast to cells exposed to an asymmetrical signal that usually increase 3'-phosphoinositides (3'-PI) transiently in the region of the activated receptors, T cells contacting APC accumulate 3'-PI across...
NF-kappa B1 p105 forms a high-affinity, stoichiometric interaction with TPL-2, a MEK kinase essential for TLR4 activation of the ERK mitogen-activated protein kinase cascade in lipopolysaccharide (LPS)-stimulated macrophages. Interaction with p105 is required to maintain TPL-2 metabolic stability and also negatively regulates TPL-2 MEK kinase activ...
Activation of the oncogenic potential of the MEK kinase TPL-2 (Cot) requires deletion of its C terminus. This mutation also
weakens the interaction of TPL-2 with NF-κB1 p105 in vitro, although it is unclear whether this is important for the activation
of TPL-2 oncogenicity. It is demonstrated here that TPL-2 stability in vivo relies on its high-aff...
NF-kappaB1 p105 functions both as a precursor of NF-kappaB1 p50 and as a cytoplasmic inhibitor of NF-kappaB. Following the stimulation of cells with tumor necrosis factor alpha (TNF-alpha), the IkappaB kinase (IKK) complex rapidly phosphorylates NF-kappaB1 p105 on serine 927 in the PEST region. This phosphorylation is essential for TNF-alpha to tri...
NF-κB1 p105 functions both as a precursor of NF-κB1 p50 and as a cytoplasmic inhibitor of NF-κB. Following the stimulation of cells with tumor necrosis factor alpha (TNF-α), the IκB kinase (IKK) complex rapidly phosphorylates NF-κB1 p105 on serine 927 in the PEST region. This phosphorylation is essential for TNF-α to trigger p105 degradation, which...
The mechanisms by which caspases are stimulated following T cell receptor engagement are presently unknown. We show here that TCR cross-linking induces caspase activation, annexin V binding, loss of cell viability, Fyn cleavage, and apoptosis in a T cell hybridoma. All these events are increased in T cells overexpressing wild-type Fyn and are inhib...
