DEK is a nuclear phosphoprotein implicated in oncogenesis and autoimmunity and a major component of metazoan chromatin. The intracellular cues that control the binding of DEK to DNA and its pleiotropic functions in DNA-and RNA-dependent processes have remained mainly elusive so far. Our recent finding that the phosphorylation status of DEK is altered during death receptor-mediated apoptosis suggested a potential involvement of DEK in stress signaling. In this study, we show that in cells committed to die, a portion of the cellular DEK pool is extensively posttranslationally modified by phosphorylation and poly(ADP-ribosyl)ation. Through interference with DEK expression, we further show that DEK promotes the repair of DNA lesions and protects cells from genotoxic agents that typically trigger poly(ADP-ribose) polymerase activation. The posttranslational modification of DEK during apoptosis is accompanied by the removal of the protein from chromatin and its release into the extracellular space. Released modified DEK is recognized by autoantibodies present in the synovial fluids of patients affected by juvenile rheumatoid arthritis/juvenile idiopathic arthritis. These findings point to a crucial role of poly(ADP-ribosyl)ation in shaping DEK's autoantigenic properties and in its function as a promoter of cell survival.Human DEK is an abundant and highly conserved nuclear protein that has long been implicated in carcinogenesis and autoimmune disorders (for a review, see references 50 and 60). Originally isolated from a specific subtype of acute myeloid leukemia (55), the gene encoding DEK is expressed under the control of transcription factors E2F and YY1 (10, 49). High levels of DEK support cell immortalization and inhibit both senescence and apoptosis, as shown in cells infected with highrisk human papillomavirus E7 (1,62,63). DEK is also upregulated in a variety of aggressive human tumors, including retinoblastoma, colon and bladder cancer, and melanoma (e.g., see references 10, 19, 28, 30, and 37).In the nucleus, DEK is involved in a variety of DNA-and RNA-dependent processes, such as DNA replication (2), splice site recognition (51), and gene transcription. Here it can function as either an activator (9) or a repressor (16,20,45). The diversity of these effects is in line with DEK's described function as a possible regulator of chromatin architecture, which may affect genome activity at various levels in a highly contextdependent manner. In fact, DEK has been shown in vitro to be a modifier of DNA higher-order structure, acting in concert with topoisomerase I to introduce constrained positive supercoils in closed circular DNA plasmids and simian virus 40 (SV40) minichromosomes (24,25,58,59). Accordingly, DEK was shown to bind to DNA in a structure-specific rather than sequence-specific manner and to reduce the accessibility of chromatin to components of the replication machinery (2, 58). Beyond its effects on DNA topology, DEK can modulate the activity of other chromatin-associated proteins, such as P/CAF and p3...
Information transmission and processing in the brain is achieved through a small family of chemical neurotransmitters and neuromodulators and a very large family of neuropeptides. In order to understand neural networks in the brain it will be necessary, therefore, to understand the connectivity, morphology, and distribution of peptidergic neurons, and to elucidate their function in the brain. In this study we characterize the distribution of substances related to Dip-allatostatin I in the honeybee brain, which belongs to the allatostatin-A (AST) peptide family sharing the conserved c-terminal sequence -YXFGL-NH(2). We found about 500 AST-immunoreactive (ASTir) neurons in the brain, scattered in 18 groups that varied in their precise location across individuals. Almost all areas of the brain were innervated by ASTir fibers. Most ASTir neurites formed networks within functionally distinct areas, e.g., the antennal lobes, the mushroom bodies, or the optic lobes, indicating local functions of the peptide. A small number of very large neurons had widespread arborizations and neurites were found in the corpora cardiaca and in the cervical connectives, suggesting that AST also has global functions. We double-stained AST and GABA and found that a subset of ASTir neurons were GABA-immunoreactive (GABAir). Double staining AST with backfills of olfactory receptor neurons or mass fills of neurons in the antennal lobes and in the mushroom bodies allowed a more fine-grained description of ASTir networks. Together, this first comprehensive description of AST in the bee brain suggests a diverse functional role of AST, including local and global computational tasks.
We investigated whether laser ablation inductively coupled plasma mass spectrometry (ICP-MS) could be used to quantify larval shell compositions of softshell clams, Mya arenaria. The composition of aragonitic otoliths has been used as a natural tag to identify natal habitat in connectivity studies of fish. If it is possible to measure larval shell reliably, this technique could also be applied to marine bivalves. To determine whether the first larval shell (prodissoconch I) could be measured independent of underlying material, we conducted laboratory experiments in which larval M. arenaria were exposed to enrichments of the stable isotope 138 Ba during different stages in shell development. We were unable to isolate the chemical signature of the prodissoconch I from subsequent life stages in all combinations of shell preparation and instrument settings. Typical instrument settings burned through the prodissoconch I on a post-settlement juvenile and at least 9 d of second larval shell (prodissoconch II) growth. Our results suggest instrumental and technical improvements are needed before laser ablation ICP-MS can be useful for connectivity studies that require analysis of larval shell on a post-settlement M. arenaria juvenile. Laser burn-through is potentially a problem in any connectivity study where it is necessary to assay the small amounts of shell material that are deposited before a larva disperses away from its natal location.
A high incidence of plasma histamine release was demonstrated in most but not all patients with POV. The probability of POV with histamine release (0.5) was higher than without histamine release (0.3), thus histamine release was shown to be one of the contributory determinants for POV in this clinical study. Thus, patients at risk for POV may benefit from a H1 + H2-receptor antagonists prophylaxis alone or in combination with other antiemetic strategies.
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