Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • PROTEIN  (37)
Collection
Keywords
  • 1
    Keywords: APOPTOSIS ; CELLS ; EXPRESSION ; GROWTH ; INHIBITOR ; tumor ; KINASE ; DEATH ; PROTEIN ; MONOCLONAL-ANTIBODY ; DEATH DOMAIN ; TUMOR-NECROSIS-FACTOR ; COMPLEX ; LIGAND ; COMPLEXES ; DOMAIN ; mechanisms ; PHOSPHORYLATION ; protein kinase ; PROTEIN-KINASE ; treatment ; antibodies ; antibody ; INDUCED APOPTOSIS ; MODULATION ; PATHOGENESIS ; DISC ; SIGNALING COMPLEX ; ANTI-APOPTOTIC MOLECULE ; CASPASE-8 ACTIVATION ; DEATH-EFFECTOR DOMAIN ; FAS/TNFR1- INDUCED APOPTOSIS ; INHIBITORY PROTEIN ; INTEGRIN ACTIVATION ; INTRACELLULAR REGULATION ; SURFACE ANTIGEN
    Abstract: Fas, upon cross-linking with Fas ligand (FasL) or Fas agonistic antibody, transduces apoptotic yet also proliferative signals, which have been implicated in tumor pathogenesis. In this study, we investigated the molecular mechanisms that control Fas-mediated signaling in glioma cells. Fas agonistic antibody, CH-11, induced apoptosis in sensitive glioma cells through caspase-8 recruitment to the Fas-mediated death-inducing signaling complex (DISC) where caspase-8 was cleaved to initiate apoptosis through a systematic cleavage of downstream substrates. In contrast, CH-11 stimulated cell growth in resistant glioma cells through recruitment of c-FLIP (cellular Fas-associated death domain (FADD)-like interleukin-1beta- converting enzyme (FLICE)-inhibitory protein) to the Fas- mediated DISC. Three isoforms of long form c-FLIP were detected in glioma cells, but only the phosphorylated isoform was recruited to and cleaved into a p43 intermediate form in the Fas-mediated DISC in resistant cells. Calcium/calmodulin- dependent protein kinase II (CaMK II) activity was up-regulated in resistant cells. Treatment of resistant cells with the CaMK II inhibitor KN-93 inhibited CaMK II activity, reduced c-FLIP expression, inhibited c-FLIP phosphorylation, and rescued CH-11 sensitivity. Transfection of CaMK II cDNA in sensitive cells rendered them resistant to CH-11. These results indicated that CaMK 11 regulates c-FLIP expression and phosphorylation, thus modulating Fas-mediated signaling in glioma cells
    Type of Publication: Journal article published
    PubMed ID: 12496285
    Signatur Availability
    BibTip Others were also interested in ...
  • 2
    Keywords: APOPTOSIS ; CELLS ; EXPRESSION ; INHIBITOR ; tumor ; CELL ; Germany ; human ; IN-VIVO ; MODEL ; DEATH ; PROTEIN ; PROTEINS ; ACTIVATION ; COMPLEX ; RESPONSES ; COMPLEXES ; primary ; DENDRITIC CELLS ; T cell ; T cells ; T-CELL ; T-CELLS ; DOWN-REGULATION ; culture ; IMMUNE-RESPONSES ; resistance ; CELL-DEATH ; UP-REGULATION ; immune response ; IMMUNE-RESPONSE ; CASPASE 8 ; FAS-MEDIATED APOPTOSIS ; SIGNALING COMPLEX ; EFFECTOR ; Bcl-2 ; FLICE-INHIBITORY PROTEIN ; CASPASE-8 ACTIVATION ; ACQUIRE
    Abstract: In the early phase of an immune response, T cells are activated and acquire effector functions. Whereas these short term activated T cells are resistant to CD95-mediated apoptosis, activated T cells in prolonged culture are readily sensitive, leading to activation-induced cell death and termination of the immune response. The translation inhibitor, cycloheximide, partially overcomes the apoptosis resistance of short term activated primary human T cells. Using this model we show in this study that sensitization of T cells to apoptosis occurs upstream of mitochondria. Neither death-inducing signaling complex formation nor expression of Bcl-2 proteins is altered in sensitized T cells. Although the caspase-8 inhibitor c-FLIPlong was only slightly down-regulated in sensitized T cells, c-FLIPshort became almost undetectable. This correlated with caspase-8 activation and apoptosis. These data suggest that c-FLIPshort, rather than c-FLIPlong, confers resistance of T cells to CD95-mediated apoptosis in the context of immune responses
    Type of Publication: Journal article published
    PubMed ID: 14764686
    Signatur Availability
    BibTip Others were also interested in ...
  • 3
    Keywords: APOPTOSIS ; CELLS ; EXPRESSION ; IN-VITRO ; INHIBITOR ; Germany ; IN-VIVO ; INHIBITION ; KINASE ; PATHWAY ; VITRO ; DEATH ; GENE ; PROTEIN ; RNA ; LINES ; gene transfer ; GENE-TRANSFER ; MECHANISM ; RAT ; CONTRAST ; mechanisms ; CELL-LINES ; PROTEIN-KINASE ; CLEAVAGE ; resistance ; CD95 ligand ; CELL-DEATH ; INDUCED APOPTOSIS ; MEMBRANE ; LINE ; KAPPA-B ; sensitivity ; OVEREXPRESSION ; cell lines ; CASPASE-8 CLEAVAGE ; SIGNALING COMPLEX ; CASPASE ; INHIBITORS ; RE ; GLIOMA ; CASPASE-8 ; OLIGONUCLEOTIDE ; NEURONS ; C-FLIP ; cell death ; ANTISENSE OLIGONUCLEOTIDE ; AUTOIMMUNE LYMPHOPROLIFERATIVE SYNDROME ; CEREBELLAR GRANULE NEURONS ; Fas/CD95 ; IMMUNE PRIVILEGE ; lifeguard ; PHOSPHATIDYLINOSITOL 3-KINASE ; PI3-kinase/ Akt
    Abstract: The contribution of Fas (CD95/APO-1) to cell death mechanisms of differentiated neurons is controversially discussed. Rat cerebellar granule neurons (CGNs) express high levels of Fas in vitro but are resistant to FasL (CD95L/APO-1L/CD178)-induced apoptosis. We here show that this resistance was mediated by a phosphatidylinositol 3-kinase (PI3-kinase)-Akt/protein kinase B (PKB)-dependent expression of lifeguard (LFG)/neuronal membrane protein 35. Reduction of endogenous LFG expression by antisense oligonucleotides or small interfering RNA lead to increased sensitivity of CGNs to FasL-induced cell death and caspase-8 cleavage. The inhibition of PI3-kinase activity sensitized CGNs to FasL-induced caspase-8 and caspase-3 processing and caspase-dependent fodrin cleavage. Pharmacological inhibition of PI3-kinase, overexpression of the inhibitory protein I kappa B, or cotransfection of an LFG reporter plasmid with dominant-negative Akt/PKB inhibited LFG reporter activity, whereas overexpression of constitutively active Akt/PKB increased LFG reporter activity. Overexpression of LFG in CGNs interfered with the sensitization to FasL by PI3-kinase inhibitors. In contrast to CGNs, 12 glioma cell lines, which are sensitive to FasL, did not express LFG. Gene transfer of LFG into these FasL-susceptible glioma cells protected against FasL-induced apoptosis. These results demonstrate that LFG mediated the FasL resistance of CGNs and that, under certain circumstances, e. g., inhibition of the PI3-kinase-Akt/PKB pathway, CGNs were sensitized to FasL
    Type of Publication: Journal article published
    PubMed ID: 16033886
    Signatur Availability
    BibTip Others were also interested in ...
  • 4
    Keywords: RECEPTOR ; APOPTOSIS ; CELLS ; tumor ; Germany ; KINASE ; GENERATION ; DEATH ; PROTEIN ; MICE ; NF-KAPPA-B ; ACTIVATION ; COMPLEX ; COMPLEXES ; MECHANISM ; mechanisms ; T-CELL ; T-CELLS ; BINDING ; PHOSPHORYLATION ; SUPPRESSION ; ALPHA ; CLEAVAGE ; TRANSGENIC MICE ; activation-induced cell death ; CELL-DEATH ; INDUCED APOPTOSIS ; LYMPHOCYTES ; BETA ; T-LYMPHOCYTES ; sensitization ; TCR ; KAPPA-B ; sensitivity ; SIGNALING COMPLEX ; IMMUNOLOGICAL SYNAPSE ; T lymphocytes ; CD95 ; signaling ; PROGRAM ; RE ; INCREASE ; IMMUNE-SYSTEM ; cell death ; ANTIGEN RECEPTORS ; HPK1 ; progenitor ; INDUCE ; NEGATIVE REGULATION ; SWITCH ; AICD ; CD28 COSTIMULATION ; HEMATOPOIETIC PROGENITOR KINASE-1 ; IKK ; KINASE-C-THETA
    Abstract: Restimulation of the T-cell receptor (TCR) in activated T cells induces CD95 (Fas/Apo-1)-mediated activation-induced cell death (AICD). The TCR-proximal mechanisms leading to AICD are elusive. Here we characterize hematopoietic progenitor kinase 1 (HPK1) as a differentially regulated TCR-proximal signaling protein involved in AICD of primary T cells. We show that HPK1 is a functional component of the endogenous I kappa B kinase (IKK) complex and is crucial for TCR-mediated NF kappa B activation. While full-length HPK1 enhances IKK beta phosphorylation, siRNA-mediated knockdown of HPK1 blunts TCR-mediated NF kappa B activation and increases cell death. We also demonstrate proteolytic processing of HPK1 into HPK1-C, specifically in AICD-sensitive primary T cells. The cleavage product HPK1-C sequesters the inactive IKK complex and suppresses NF kappa B upon TCR restimulation by binding to IKK alpha and IKK beta. T cells of HPK1-C transgenic mice are sensitized towards TCR-mediated AICD. Consequently, preventing HPK1-C generation in primary T cells by siRNA-mediated knockdown results in decreased AICD. Thus, these results show a novel mechanism of sensitization of T lymphocytes towards AICD by suppression of NF kappa B, and propose that HPK1 is a life/death switch in T lymphocytes
    Type of Publication: Journal article published
    PubMed ID: 16341093
    Signatur Availability
    BibTip Others were also interested in ...
  • 5
    Keywords: APOPTOSIS ; CELLS ; EXPRESSION ; Germany ; DEATH ; PROTEIN ; PROTEINS ; LINES ; NF-KAPPA-B ; ACTIVATION ; COMPLEX ; COMPLEXES ; T-CELLS ; CELL-LINES ; VARIANTS ; UP-REGULATION ; NUMBER ; LINE ; cell lines ; REGULATOR ; SIGNALING COMPLEX DISC ; SIGNALING COMPLEX ; EFFECTOR ; CD95 APO-1/FAS ; CD95 ; HUMAN T-CELLS ; PROGRAM ; RE ; CASPASE-8 ; MEDIATED APOPTOSIS ; regulation ; CD95-MEDIATED APOPTOSIS ; SIGNALING COMPLEXES ; FLICE-INHIBITORY PROTEINS
    Abstract: c-FLIPs (c-FLICE inhibitory proteins) play an essential role in regulation of death receptor-induced apoptosis. Multiple splice variants of c-FLIP have been described on the mRNA level; so far only two of them, c-FLIPL and c-FLIPS, had been found to be expressed at the protein level. In this report, we reveal the endogenous expression of a third isoform of c-FLIP. We demonstrate its presence in a number of T and B cell lines as well as in primary human T cells. We identified this isoform as c-FLIPR, a death effector domain-only splice variant previously identified on the mRNA level. Importantly, c-FLIPR is recruited to the CD95 (Fas/APO-1) death-inducing signaling complex upon CD95 stimulation. Several properties of c-FLIPR are similar to c-FLIPS: both isoforms have a short half-life, a similar pattern of expression during activation of primary human T cells, and are strongly induced in T cells upon CD3/CD28 costimulation. Taken together, our data demonstrate endogenous expression of c-FLIPR and similar roles of c-FLIPR and c-FLIPS isoforms in death receptor-mediated apoptosis
    Type of Publication: Journal article published
    PubMed ID: 15701649
    Signatur Availability
    BibTip Others were also interested in ...
  • 6
    Keywords: RECEPTOR ; APOPTOSIS ; Germany ; DEATH ; PROTEIN ; PROTEINS ; ACTIVATION ; COMPLEX ; COMPLEXES ; MECHANISM ; INDUCTION ; INITIATION ; MOLECULAR-CLONING ; FLICE ; OLIGOMERIZATION ; SIGNALING COMPLEX ; CD95 ; COMPLEX DISC ; GEL-ELECTROPHORESIS ; signaling ; RE ; CAP3 ; MOUSE CASPASE-8
    Abstract: Formation of the CD95 (APO-1/Fas) death inducing signaling complex (DISC) plays a central role in CD95 signaling. Previously, CD95 DISC composition was analyzed by two-dimensional gel electrophoresis and four major cytotoxicity-associated proteins (CAP1-4) were found. CAP1 and CAP2 were defined to be unmodified and phosphorylated FADD, respectively. CAP4 was identified as procaspase-8a. CAP3, however, has remained elusive. In this study, we demonstrate that CAP3 is an intermediate of procaspase-8 processing. CAP3 is generated within seconds of DISC formation and subsequently processed to the prodomain of procaspase-8a that is known as p26 (CAP5). These findings lead to new insights into the mechanism of procaspase-8 processing and apoptosis initiation
    Type of Publication: Journal article published
    PubMed ID: 16179941
    Signatur Availability
    BibTip Others were also interested in ...
  • 7
    Keywords: RECEPTOR ; APOPTOSIS ; CELLS ; Germany ; KINASE ; PATHWAY ; DEATH ; PROTEIN ; PROTEINS ; NF-KAPPA-B ; ACTIVATION ; COMPLEX ; COMPLEXES ; MECHANISM ; DENDRITIC CELLS ; T-CELLS ; BINDING ; CLEAVAGE ; CELL-DEATH ; INDUCED APOPTOSIS ; LYMPHOCYTES ; B-CELLS ; SIGNALING COMPLEX ; signaling ; MALIGNANT-CELLS ; RE ; FAS ; CASPASE ACTIVATION ; C-FLIP ; IKK ; death receptor ; FLICE-INHIBITORY PROTEINS ; LONG FORM ; RECEPTOR-INDUCED APOPTOSIS
    Abstract: c-FLIP proteins (isoforms: c-FLIPL, c-FLIPS, and c-FLIPR) play an essential role in the regulation of death receptor - induced apoptosis. Here, we demonstrate that the cytoplasmic NH2-terminal procaspase-8 cleavage product of c-FLIP (p22-FLIP) found in nonapoptotic malignant cells, primary T and B cells, and mature dendritic cells (DCs) strongly induces nuclear factor kappa B (NF-kappa B) activity by interacting with the I kappa B kinase (IKK) complex via the IKK gamma subunit. Thus, in addition to inhibiting apoptosis by binding to the death-inducing signaling complex, our data demonstrate a novel mechanism by which c-FLIP controls NF-kappa B activation and life/death decisions in lymphocytes and DCs
    Type of Publication: Journal article published
    PubMed ID: 16682493
    Signatur Availability
    BibTip Others were also interested in ...
  • 8
    Keywords: RECEPTOR ; APOPTOSIS ; CANCER ; IN-VITRO ; tumor ; CELL ; IN-VIVO ; MODEL ; MODELS ; PATHWAY ; PATHWAYS ; VITRO ; VIVO ; SYSTEM ; SYSTEMS ; DEATH ; GENE ; GENES ; microarray ; PROTEIN ; transcription ; EPITHELIA ; TUMORS ; validation ; MICE ; TRANSCRIPTION FACTOR ; KERATINOCYTES ; SKIN ; BIOLOGY ; cell cycle ; CELL-CYCLE ; CYCLE ; TARGET ; ISOFORM ; ENCODES ; PROMOTER ; PROMOTERS ; REQUIRES ; DNA-DAMAGE ; BAX ; HUMAN KERATINOCYTES ; SQUAMOUS-CELL CARCINOMA ; TARGETS ; RECEPTORS ; MICROARRAY ANALYSIS ; epidermis ; TRAIL ; DEATH RECEPTORS ; tetramer ; CD95 ; chemoresistance ; review ; TUMOR-SUPPRESSOR ; keratinocyte ; LIGHT ; TUMORIGENESIS ; development ; STRATIFIED EPITHELIA ; TARGET GENES ; analysis ; P63 ; death receptor ; EPITHELIUM ; EPITHELIAL TUMORS ; KINASE C-ABL ; P53-DEPENDENT APOPTOSIS ; REGULATES P73 ; USA ; function ; in vivo ; E ; PROTECTS ; MAINTENANCE ; inactive ; cornification ; FAMILY-MEMBER GENES ; GENE ENCODES ; IKK alpha ; ISOFORM EXPRESSION ; P53 HOMOLOG P63
    Abstract: The epidermis is a multilayered stratified epithelium, continuously regenerated by differentiating keratinocytes, that requires the transcription factor p63 for its development and maintenance. The TP63 gene encodes two major protein isoforms, TAp63 and Delta Np63, which have both transactivating and transcriptional repressing activities and regulate a wide range of target genes. TAp63 shows clear pro-apoptotic activity, mediated both by death receptors (CD95, TNF, TRAIL) and mitochondrial (bax, puma) pathways. Conversely, DNp63 protects from apoptosis by directly competing for TAp63 target promoters or sequestering it, forming inactive tetramers. Accordingly, p63 is expressed in epithelial tumors, contributing to both tumorigenesis and chemoresistance. However, the predominant physiological role of p63 is in epithelial development, as demonstrated by the lack of epidermis and other epithelia in p63-deficient mice. The specific role of TAp63 and DNp63 isoforms in epithelial development remains mostly unclear. Nevertheless, recent work utilizing in vivo genetic complementation of TAp63 and/or DNp63 into a p63 null background has shed new light into the specific functions of the two isoforms and allowed the in vivo validation of several p63 transcriptional targets, originally identified by microarray analysis in in vitro systems. However, despite concerted efforts to address the role of p63 isoforms, several questions remain unanswered. The main aim of this review is to critically discuss the data available in the literature and thoroughly analyze the models proposed
    Type of Publication: Journal article published
    Signatur Availability
    BibTip Others were also interested in ...
  • 9
    Keywords: APOPTOSIS ; CELLS ; BLOOD ; CELL ; Germany ; IN-VIVO ; KINASE ; PATHWAY ; PATHWAYS ; SYSTEM ; DEATH ; PROTEIN ; PROTEINS ; RNA ; MICE ; NF-KAPPA-B ; ACTIVATION ; MECHANISM ; FAMILY ; primary ; INDUCTION ; T cell ; T cells ; T-CELL ; T-CELLS ; MEMBER ; MEMBERS ; TRANSGENIC MICE ; CD95 ligand ; CELL-DEATH ; INDUCED APOPTOSIS ; LYMPHOCYTES ; B-CELLS ; SIGNALING COMPLEX ; Bcl-2 ; molecular ; MOLECULAR-BASIS ; RE ; FAMILIES ; LIFE ; LEVEL ; cell death ; ANTIGEN RECEPTORS ; progenitor ; SUPPRESSOR ; FAS LIGAND ; AICD ; HEMATOPOIETIC PROGENITOR KINASE-1 ; USA ; B-LYMPHOCYTES ; FATE ; FRAGMENT ; FAMILY-MEMBER BIM ; B-CELL ; KINASE-1 ; EXPANSION ; caspase-3 ; block ; B cells ; BCL-2 FAMILY ; COMPLEMENT ; FULL-LENGTH ; MEDIATED CLEAVAGE ; SMALL INTERFERING RNA
    Abstract: Life and death of peripheral lymphocytes is strictly controlled to maintain physiologic levels of T and B cells. Activation-induced cell death (AICD) is one mechanism to delete superfluous lymphocytes by restimulation of their immunoreceptors and it depends partially on the CD95/CD95L system. Recently, we have shown that hematopoietic progenitor kinase 1 (HPK1) determines T-cell fate. While full-length HPK1 is essential for NF-KB activation in T cells, the C-terminal fragment of HPK1, HPK1-C, suppresses NF-KB and sensitizes toward AICD by a yet undefined cell death pathway. Here we show that upon IL-2-driven expansion of primary T cells, HPK1 is converted to HPK1-C by a caspase-3 activity below the threshold of apoptosis induction. HPK1-C selectively blocks induction of NF-kappa B-dependent antiapoptotic Bcl-2 family members but not of the proapoptotic Bcl-2 family member Bim.Interestingly, T and B lymphocytes from HPK1-C transgenic mice undergo AICD independently of the CD95/CD95L system but involving caspase-9. Knock down of HPK1/HPK1-C or Bim by small interfering RNA shows that CD95L-dependent and HPK1/HPK1-C-dependent cell death pathways complement each other in AICD of primary T cells. Our results define HPK1-C as a suppressor of antiapoptotic Bcl-2 proteins and provide a molecular basis for our understanding of CD95L-independent AICD of lymphocytes
    Type of Publication: Journal article published
    PubMed ID: 17712048
    Signatur Availability
    BibTip Others were also interested in ...
  • 10
    Keywords: CELLS ; EXPRESSION ; INHIBITOR ; tumor ; CELL ; Germany ; INHIBITION ; KINASE ; GENERATION ; DEATH ; PROTEIN ; RNA ; DRUG ; TIME ; COMPLEX ; COMPLEXES ; DNA ; INDUCTION ; T cell ; T cells ; T-CELL ; T-CELLS ; BIOLOGY ; PROTEIN-KINASE ; SIGNAL ; MITOCHONDRIA ; SUPEROXIDE ; OXYGEN ; FAS LIGAND EXPRESSION ; MULTIPLE-SCLEROSIS ; reactive oxygen species ; signaling ; PROGRAM ; RE ; assembly ; SUPEROXIDE-PRODUCTION ; HYDROGEN-PEROXIDE ; REACTIVE OXYGEN ; AICD ; CHAPERONE ; USA ; ROS ; PREVENTS ; CD95L ; block ; SMALL INTERFERING RNA ; superoxide dismutase ; COMPLEX-I ; DOPAMINERGIC-NEURONS ; HEART-MITOCHONDRIA ; LYMPHOCYTE-ACTIVATION ; RECEPTOR STIMULATION ; ROTENONE INHIBITION
    Abstract: Reactive oxygen species (ROS) play a key role in regulation of activation-induced T-cell death (AICD) by induction of CD95L expression. However, the molecular source and the signaling steps necessary for ROS production are largely unknown. Here, we show that the proximal T-cell receptor-signaling machinery, including ZAP70 (zeta chain-associated protein kinase 70), IAT (linker of activated T cells), SLP76 (SH2 domain-containing leukocyte protein of 76 kDa), PLC gamma 1 (phospholipase C gamma 1), and PKC theta (protein kinase C theta), are crucial for ROS production. PKC theta is translocated to the mitochondria. By using cells depleted of mitochondrial DNA, we identified the mitochondria as the source of activation-induced ROS. Inhibition of mitochondrial electron transport complex I assembly by small interfering RNA (siRNA) -mediated knockdown of the chaperone NDUFAF1 resulted in a block of ROS production. Complex I-derived ROS are converted into a hydrogen peroxide signal by the mitochondrial superoxide dismutase. This signal is essential for CD95L expression, as inhibition of complex I assembly by NDUFAF1-specific siRNA prevents AICD. Similar results were obtained when metformin, an antidiabetic drug and mild complex I inhibitor, was used. Thus, we demonstrate for the first time that PKC theta-dependent ROS generation by mitochondrial complex I is essential for AICD
    Type of Publication: Journal article published
    Signatur Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...