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TP53 mutation pattern of esophageal squamous cell carcinomas in a high risk area (Southern Brazil): role of life style factors.

In an attempt to correlate the TP53 mutation pattern of squamous cell carcinomas of the esophagus (ESCC) and life style factors of patients from the high risk area Rio Grande do Sul, Brazil, 135 ESCC were analyzed, after prescreening by p53 immunohistochemistry, by SSCP and DNA sequencing of TP53, exon 5-9. Forty-nine somatic TP53 mutations (and 1 case with p53 polymorphism) were identified as missense (n = 39), frameshift (n = 6), silent (n = 1), amber (n = 1) or intron border mutations (n = 2) that cause splicing aberrations. They were preferentially found in exon 5 (36.7%) and exon 8 (32.7%). Several mutations were located in the mutation hot spot codons 248, 273 and 282, mainly at CpG sites. Transition mutations were observed in 53.1% (among them 50% G > A), transversion mutations in 34.7% (among them 47.1% G > T) and frameshifts in 12.2%, the latter 2 mainly in smokers and alcohol drinkers. Transitions were more prevalent in females than in males (p < 0.05). TP53 mutations, mainly transversions, were more frequently found in heavy smokers (p = 0.03), with the same tendency after chronic alcohol consumption. Comparison with the worldwide IARC database disclosed differences in the TP53 mutation pattern of the Brazilian tumors, with a higher accumulation of TP53 mutations in exon 8 and a higher prevalence of transition mutations. Mutations at the reported hot spot codon 176 were missing. Although difficult because of the documented coexposure to various life style risk factors in most patients of this series, the hypothesis is proposed that besides smoking and alcohol drinking the commonly consumed hot mate tea in this high risk area for ESCC is responsible for this different pattern of TP53 mutations because of chronic hyperthermic irritation and inflammation in the esophagus with an endogenous formation of radicals or carcinogenic factors that lead to a higher prevalence of transition mutations.

Adult↗

Membrane cofactor protein (CD46) of complement. Processing differences related to alternatively spliced cytoplasmic domains.

Membrane cofactor protein (MCP, CD46), a widely distributed regulatory protein, inhibits complement activation on host cells and serves as a measles virus receptor. Most cells express four isoforms (with one of two cytoplasmic tails, CYT-1 or CYT-2). Previously, we noted that MCP precursors had variable intracellular processing. Therefore, we characterized the intracellular transport of individual MCP isoforms. Transfectants were used for pulse-chase analyses. MCP isoforms bearing CYT-1 chased into their mature, surface forms with a half-life (t1/2) of 10-13 min while those with CYT-2 required 35-40 min. The precursor of a tail-less mutant possessed a t1/2 of 160-165 min. Chimeras were constructed that added both tails in opposite orientation onto the isoform (i.e. CYT 1 + 2 or CYT 2 + 1). Chimera 1 + 2 precursor processed with a t1/2 of 35-37 min, similar to CYT-2. Chimera 2 + 1 had a t1/2 of 15-19 min, more closely resembling CYT-1. Thus, in both cases the carboxyl-terminal tail controlled the processing rate. Deletions were made in the beginning, middle, and carboxyl terminus of CYT-1. Deletion of the first or middle six amino acids had no effect on the processing rate. However, deletion of the terminal tetrapeptide (FTSL) slowed the rate to 30-32 min, suggesting that this sequence facilitates exit from the endoplasmic reticulum.

Alternative Splicing↗

A nuclear post-transcriptional mechanism mediates the induction of fibronectin by glucocorticoids.

Treatment of the human fibrosarcoma cell line HT-1080 with glucocorticoids results in the induction of fibronectin (FN) protein and mRNA synthesis. We tested the contribution of transcriptional and post-transcriptional mechanisms in the regulation of FN by the synthetic glucocorticoid dexamethasone (DEX). Using nuclear run-on experiments, we found that the DEX-dependent induction of FN occurs primarily at the post-transcriptional level. The half-life of total FN mRNA was not affected by hormone treatment indicating that the induction of FN gene expression is not due to stabilization of the mature message. Interestingly, the induction by DEX was present at the level of nuclear FN RNA. We found that polyadenylation and alternative splicing of the ED-B domain of the FN transcript were not affected by glucocorticoid treatment. However, DEX was found to increase the steady-state level of unspliced FN transcript. Our data indicate that DEX exerts its effect on FN expression predominantly at the post-transcriptional level by a mechanism that, unlike most examples of post-transcriptional regulation by glucocorticoids, acts in the nucleus. Furthermore, they suggest that glucocorticoids activate a mechanism to stabilize the unspliced FN RNA. In an attempt to localize the FN RNA sequences mediating the DEX-dependent induction, we performed transfection analyses of FN minigene constructs. We suggest that the DEX-dependent regulatory elements are located in the introns since no such elements were found in the 8 kb FN mRNA.

Alternative Splicing↗

Group I twintrons: genetic elements in myxomycete and schizopyrenid amoeboflagellate ribosomal DNAs.

Protists are unicellular eukaryotes which represent a significant fraction of the global biodiversity. The myxomycete Didymium and the schizopyrenid amoeboflagellate Naegleria are distantly related protists. However, we have noted several striking similarities in life cycle, cell morphology, and ribosomal DNA organization between these organisms. Both have multicopy nuclear extrachromosomal ribosomal DNAs. Here the small subunit ribosomal RNA genes are interrupted by an optional group I twintron, a novel category among the group I introns. Group I twintrons are mobile self-splicing introns of 1.3-1.4 kb in size, with a complex organization at the RNA level. A group I twintron consists of two distinct ribozymes (catalytic RNAs) with different functions in RNA processing, and an open reading frame encoding a functional homing endonuclease--all with prospects of application as molecular tools in biotechnology. Updated RNA secondary structure models of group I twintrons, as well as an example of in vitro ribozyme activity, are presented. We suggest that the group I twintrons have been independently established in myxomycetes and schizopyrenid amoeboflagellates by horizontal gene transfer due to a combination of the phagocytotic behavior in natural environments and the extrachromosomal multicopy nature of ribosomal DNA.

Animals↗

Giant viruses infecting algae.

Paramecium bursaria chlorella virus (PBCV-1) is the prototype of a family of large, icosahedral, plaque-forming, double-stranded-DNA-containing viruses that replicate in certain unicellular, eukaryotic chlorella-like green algae. DNA sequence analysis of its 330, 742-bp genome leads to the prediction that this phycodnavirus has 376 protein-encoding genes and 10 transfer RNA genes. The predicted gene products of approximately 40% of these genes resemble proteins of known function. The chlorella viruses have other features that distinguish them from most viruses, in addition to their large genome size. These features include the following: (a) The viruses encode multiple DNA methyltransferases and DNA site-specific endonucleases; (b) PBCV-1 encodes at least part, if not the entire machinery to glycosylate its proteins; (c) PBCV-1 has at least two types of introns--a self-splicing intron in a transcription factor-like gene and a splicesomal processed type of intron in its DNA polymerase gene. Unlike the chlorella viruses, large double-stranded-DNA-containing viruses that infect marine, filamentous brown algae have a circular genome and a lysogenic phase in their life cycle.

Biological Evolution↗

[Osteopetrosis with carbonic anhydrase II deficiency: report of 24 cases].

Twenty four patients suffering from osteopetrosis caused by carbonic anhydrase II deficiency are colliged. This pathology seems to be frequent in Tunisia. Mental retardation is present in 52%, 85% of patients have short stature and 25% have optic atrophy. All affected subjects show craniofacial disproportion and dental anomalies. Twenty patients have at least one bone fracture. Metabolic acidosis is constant: it is profound during the first life decade. A severe selective reduction of carbonic anhydrase II in erythrocyte is confirmed in 18 cases. Osteosclerosis and defective skeletal modelling are constant, cerebral calcification can be seen at the scanner approximately at the age of two years and six months. All patients are homozygous for a splice junction mutation in intron 2 of the carbonic anhydrase II gene, this mutation does not seem to protect patients from bone fractures nor induce a severe metabolic acidosis.

Adolescent↗

Rat cystathionine beta-synthase: expression of four alternatively spliced isoforms in transfected cultured cells.

The gene for rat cystathionine beta-synthase consists of 17 exons. Its transcripts are alternatively spliced, forming four distinct mRNA species. Type III consists of exons 1 through 12, 14, 15, and 17; type I also contains exon 16. The open reading frame of type IV spans exons 1-->13; type II, 3-->13. We cloned the corresponding cDNAs into appropriate expression vectors and inserted the constructs into Escherichia coli (I, III, and IV) and Chinese hamster (CH) cells (I through IV); all sequences were transcribed and translated. Catalytic activity was observed only for types I and III in lysates of transfected CH cells and transformed E. coli. The catalytic and kinetic properties of I and III were identical despite their structural difference (exon 16). Both isoforms exhibited 6 mM Km constants for homocysteine which were reduced approximately eightfold by AdoMet; this elucidates the mechanism by which AdoMet regulates synthase activity. The four isoforms were differentially degraded by transfected cultured cells. Type III (t1/2 = 18 h) was degraded at 1/3 the rate of type I (t1/2 = 6 h); thus the 14 amino acid residues encoded by exon 16 appear to enhance degradation of CBS. The half-lives of both types II and IV were markedly shorter (ca. 1 h). Western blots comparing rat liver to lysates from transfected CH cells revealed that hepatocytes express both isoforms. Type III was predominant, as predicted by its longer half-life and more abundant mRNA. PCR analysis of cDNA from various tissues revealed that type III mRNA was preferred in liver, kidney, and heart; equal amounts of I and III were found in brain.

Alternative Splicing↗

Developmental regulation of D beta reading frame and junctional diversity in T cell receptor-beta transcripts from human thymus.

During fetal life, both Ig and TCR-gamma delta repertoires are enriched for a specific set of Ag receptors with limited diversity. In order to test the hypothesis that diversification of the human TCR-beta repertoire also follows a developmental program, we examined TCR-beta DJ and VDJ transcripts from fetal and adult thymi. A consistent bias for D beta 1.1 and J beta 1.1 was present in DJ transcripts amplified from 8-wk gestation thymi. Although it is possible to splice and translate D beta 1.1 in all three reading frames, 8-wk gestation fetal DJ transcripts were enriched for D beta 1.1 spliced to J beta 1.1 in reading frame one. Preference for D beta 1.1 reading frame one and for use of J beta 1.1 dwindled with increasing gestational age. Reading frame bias was not affected by the insertion of non-germ-line-encoded nucleotides (N regions) or by the site of gene splicing. In contrast, choice of reading frame and use of J beta 1.1 appeared random in VDJ transcripts from the same 8-wk gestation and adult thymic samples. Among the occasional VDJ transcripts that contained D beta 1.1-J beta 1.1 rearrangements, use of D beta reading frame one was rare. Up to 75% of DJ and VDJ transcripts at 8-wk gestation lacked N regions. Both the percentage of DJ and VDJ transcripts with N regions and the average number of inserted nucleotides per transcript increased with gestational age. Primarily as a result of enhanced N region addition, both the length and sequence diversity of the VDJ junctions increased markedly from 8-wk gestation to adult life with a concomitant increase in the potential size of the TCR-alpha beta repertoire. Terminal deoxynucleotidyl-transferase (TdT), the enzyme associated with N region addition, has not been detected in thymus before 19 wk of gestation. However, we were able to amplify TdT mRNA from all fetal thymi examined. This suggests that TdT may be expressed as early as 8 wk gestation, although at low levels. The early fetal thymus appears enriched for a population of thymocytes that produce minimal quantities of TdT, express a special set of TCR-beta DJ transcripts, and generate a TCR-beta repertoire with limited diversity. These findings support the hypothesis that limitations in the diversity of the TCR repertoire imposed at the time of gene rearrangement contribute to the immaturity of the fetal immune response.

Adult↗

Thyroid hormone influences the maturation of apolipoprotein A-I messenger RNA in rat liver.

Chronic administration of thyroid hormone (T3) increases apolipoprotein (apo) A-I gene expression in rat liver. That transcriptional activity of the apoA-I gene is reduced to 50% of control, whereas abundance levels of nuclear and total cellular apoA-I mRNA are increased 3-fold, implies more effective apoA-I mRNA maturation. To study hormonal effects on apoA-I RNA processing, we quantified mRNA precursors in control and T3-treated rats (50 micrograms/100 g body weight for 7 days). Northern blotting, amplification of reverse-transcribed RNA, and ribonuclease protection assays showed that the splicing pathway is branched, in that either intron 1 or intron 2 is removed first from the primary transcript, whereas intron 3 is removed last. In T3-treated rats, abundance levels of the primary transcript, the intron 1-containing precursor devoid of intron 2, the intron 2-containing precursor devoid of intron 1, the intron 3-containing precursor lacking both introns 1 and 2, and nuclear mRNA were 65, 183, 78, 195, and 268% of controls. Compared with control rats, the half-life of the intron 1-containing precursor, measured after injection of actinomycin D, was increased 2-fold in T3-treated rats. In contrast, half-lives of the primary transcript and the intron 2-containing precursor were similar in control and T3-treated rats. Ribonuclease protection assays revealed an RNA species extending from the transcription start site close to the 3' end of intron 1. The abundance of this RNA fragment, probably representing a degradation product, was 2.5-fold higher in control than in T3-treated animals (p < 0.001). Sequences of apoA-I mRNA precursors were identical in control and T3-treated rats which excluded hormonal effects on splice-site selection or post-transcriptional editing of apoA-I transcripts. Compartmental modeling of apoA-I mRNA processing suggested that chronic thyroid hormone administration enhances apoA-I mRNA maturation more than 7-fold by protecting the intron 1-containing precursor devoid of intron 2 from degradation and by facilitating the splicing of intron 1 from this precursor.

Animals↗

The SNARE Vti1a-beta is localized to small synaptic vesicles and participates in a novel SNARE complex.

Specific soluble N-ethylmaleimide-sensitive factor attachment protein (SNAP) receptor (SNARE) proteins are required for different membrane transport steps. The SNARE Vti1a has been colocalized with Golgi markers and Vti1b with Golgi and the trans-Golgi network or endosomal markers in fibroblast cell lines. Here we study the distribution of Vti1a and Vti1b in brain. Vti1b was found in synaptic vesicles but was not enriched in this organelle. A brain-specific splice variant of Vti1a was identified that had an insertion of seven amino acid residues next to the putative SNARE-interacting helix. This Vti1a-beta was enriched in small synaptic vesicles and clathrin-coated vesicles isolated from nerve terminals. Vti1a-beta also copurified with the synaptic vesicle R-SNARE synaptobrevin during immunoisolation of synaptic vesicles and endosomes. Therefore, both synaptobrevin and Vti1a-beta are integral parts of synaptic vesicles throughout their life cycle. Vti1a-beta was part of a SNARE complex in nerve terminals, which bound N-ethylmaleimide-sensitive factor and alpha-SNAP. This SNARE complex was different from the exocytic SNARE complex because Vti1a-beta was not coimmunoprecipitated with syntaxin 1 or SNAP-25. These data suggest that Vti1a-beta does not function in exocytosis but in a separate SNARE complex in a membrane fusion step during recycling or biogenesis of synaptic vesicles.

Alternative Splicing↗

Competitive polymerase chain reaction as a method to detect the amplification of bcr-abl gene of chronic myeloid leukemia.

BACKGROUND AND OBJECTIVES: The chimeric product of the bcr-abl rearranged gene is critical in the pathogenesis of chronic myeloid leukemia (CML), yet its role in the progression of the disease remains unclear. There is some evidence that increased bcr-abl expression levels, possibly due to gene amplification, precede the clonal evolution of CML hematopoietic progenitors toward a fully transformed phenotype and might be involved in their resistance to interferon-alpha or tyrosine kinase inhibitors. DESIGN AND METHODS: To quantify the bcr-abl gene both at the genomic and at the transcriptional levels we developed a competitive polymerase chain reaction (PCR) strategy. The competitive PCR technique is based upon the co-amplification of the sample template (target) together with increasing amounts of a DNA fragment (competitor) sharing with the target the primer recognition sites, but differing in size. We constructed a competitor for the quantification of both b2a2 and b3a2 alternative splicing forms of the bcr-abl chimera and established the accuracy and reproducibility of our competitive strategy in a clone of the murine 32DG hematopoietic cell line (32D LG7), which bears a stable integration of a single copy of p210 bcr-abl fusion gene. We utilized this technique to follow, over a period of 200 days, the fusion gene copy numbers and transcription rates in several p210 bcr-abl-transduced 32D cell clones, an experimental condition mimicking the evolution of CML myeloid progenitors in vivo. RESULTS: Our results are consistent with p210 bcr-abl overexpression but not gene amplification associated with their clonal evolution. Increased p210 bcr-abl transcription rate is associated with the abrogation of radiation-induced apoptotic cell death, suggesting a role for the chimeric gene expression level in cell life expectancy after a genotoxic insult. INTERPRETATION AND CONCLUSIONS: We conclude that the assessment of gene amplification and expression might serve to improve prognostic classification and follow-up of CML patients.

Alternative Splicing↗

Differentially expressed, abundant trans-spliced cDNAs from larval Brugia malayi.

Isolation and cloning of abundant reverse transcriptase-polymerase chain reaction (RT-PCR) products from the filarial nematode Brugia malayi using the conserved nematode spliced leader sequence and poly A as amplification targets has allowed us to identify abundant, stage specific transcripts from infective and post-infective larvae. The predicted protein products of the most prominent full-length transcripts from mosquito-derived L3 parasites are: (i) Bm-ALT-1, a homologue of a Dirofilaria immitis abundant larval protein: (ii) Bm-CPI-1, a cystatin-type cysteine protease inhibitor; (iii) Bm-ALT-3, a novel predicted 6 kDa glycine/tyrosine-rich protein; and (iv) Bm-TPH-1, a homologue of a mammalian translationally-controlled tumour protein. Some transcripts were not full-length but had mis-primed at A-rich stretches of coding sequence: the most abundant of these was Bm-col-3, a which encodes a collagen homologous to Bp-COL-1 of Brugia pahangi. Similar analysis of abundant spliced leader (SL)/oligo-dT products from fourth-stage larvae 9 days post-infection yielded two dominant transcripts: (i) Bm-cdd-1, which encodes a protein with homology to cytidine deaminase, differing at only one amino acid position from its homologue described in Brugia pahangi; and (ii) the same truncated form of Bm-col-3 found in L3 preparations. Expression of the major transcripts was assessed by PCR amplification of cDNA libraries derived from each stage of the life cycle. alt1, alt-3 and cpi-1 were all found to be specific to the L3 stage, while cdd-1 was found only in the L4 cDNA library. Expression of these larval-specific transcripts was not detected in either microfilarial or adult libraries.

Aedes↗

Analysis of multiple mRNAs from pathogenic equine infectious anemia virus (EIAV) in an acutely infected horse reveals a novel protein, Ttm, derived from the carboxy terminus of the EIAV transmembrane protein.

Transcription of pathogenic equine infectious anemia virus (EIAV) in an acutely infected horse was examined by using the polymerase chain reaction and nucleotide sequencing. Four spliced transcripts were identified in liver tissue, in contrast to the multiplicity of alternatively spliced messages reported for in vitro-propagated human immunodeficiency virus, simian immunodeficiency virus, and, to a lesser extent, EIAV. Nucleotide sequence analysis demonstrated that three of these mRNAs encode known viral proteins: the envelope precursor, the product of the S2 open reading frame, and the regulatory proteins Tat and Rev. The fourth transcript encodes a novel Tat-TM fusion protein, Ttm. Ttm is a 27-kDa protein translated from the putative tat CTG initiation codon and containing the carboxy-terminal portion of TM immediately downstream from the membrane-spanning domain. p27ttm is expressed in EIAV-infected canine cells and was recognized by peptide antisera against both Tat and TM. Cells transfected with ttm cDNA also expressed p27ttm, which appeared to be localized to the endoplasmic reticulum or Golgi apparatus by indirect immunofluorescence. The carboxy terminus of lentiviral TM proteins has previously been shown to influence viral infectivity, growth kinetics, and cytopathology, suggesting that Ttm plays an important role in the EIAV life cycle.

Amino Acid Sequence↗

Seventeen-year follow-up of hypophosphatasia diagnosed in middle-aged siblings harboring a novel intronic and a rare missense ALPL gene mutation.

Hypophosphatasia (HPP) is the rare inborn-error-of-metabolism that features impaired mineralization of the skeleton and teeth due to a deactivating mutation or mutations of the gene ALPL which encodes the tissue-nonspecific isoenzyme of alkaline phosphatase (TNSALP). We report 17-year follow-up of twin sisters and a brother referred in middle-age for painful proximal femoral "stress fractures" and then diagnosed with HPP. They reported generalized muscle and bone pain, metatarsal fractures, arthropathy and, since childhood, tooth loss. Their concordant findings were explained by compound heterozygosity in ALPL for a rare maternal missense mutation (c.1403C&#xa0;>&#xa0;T, p.Ala468Val) in exon 12, together with a novel presumably paternal change (c.863-14G&#xa0;>&#xa0;A) predicting a cryptic mRNA splice site in intron 8. Fractures continued during follow-up until one sister received a three-and-one-half-year course of hydroxyapatite-targeted TNSALP supplementation therapy (asfotase alfa) during which substantial improvement occurred in her clinical, biochemical, and functional parameters as well as quality of life. Following subsequent unplanned treatment cessation she suffered significant clinical deterioration, including new fractures and loss of mobility. Her bone histopathology documented osteomalacia. Treatment resumption restored its benefits. Among ten asymptomatic family members evaluated in this four-generation kindred, eight were carriers heterozygous for either ALPL mutation. Those harboring the maternal missense defect manifested mild hypophosphatasemia, suggesting a dominant-negative mutation effect. This experience underscores the importance of in-depth phenotyping and then clinical follow-up to characterize ALPL variant combinations, and for maintaining effective asfotase alfa treatment.

Humans↗

Analysis of novel human papillomavirus type 16 late mRNAs in differentiated W12 cervical epithelial cells.

The life cycle of human papillomavirus type 16 (HPV16) is intimately linked to differentiation of the epithelium it infects, and late events in the life cycle are restricted to the suprabasal layers. Here we have used 5'RACE of polyadenylated RNA isolated from differentiated W12 cells (cervical epithelial cells containing episomal copies of the HPV16 genome) that express virus late proteins to map virus late mRNAs. Thirteen different transcripts were identified. Extensive alternative splicing and use of two late polyadenylation sites were noted. A novel promoter located in the long control region was detected as well as P97 and Plate. Promoters in the E4 and E5 open reading frames were active yielding transcripts where L1 or L2 respectively are the first open reading frames. Finally, mRNAs that could encode novel proteins E6*-- *E7, E6*-- E4, E1--*E4 and E1-- E2C (putative repressor E2) were identified, indicating that HPV16 may encode more late proteins than previously accepted.

Alternative Splicing↗

Properties of the Plasmodium falciparum homologue of a protective vaccine candidate of Plasmodium yoelii.

We describe an unusual tryptophan-rich protein of Plasmodium falciparum that contains threonine-rich repeats. The protein is encoded by a 2.5 kb gene with a two-exon structure including a short AT-rich intron that is spliced out of the mature message. The 5' end of the gene encodes a hydrophobic region, which is assumed to be a signal peptide. The peptide sequence is characterised by a tryptophan-rich region and a block of degenerate threonine repeats. The protein is synthesised throughout the asexual life cycle and has an apparent molecular weight of approximately 94 kDa. It has a variable molecular weight in different strains of P. falciparum. Length polymorphisms can be found in the intron region and the second exon. Four single nucleotide mutations are localised in the tryptophan-rich region and two were found in the threonine-repeat block. Homology searches based on gene structure and amino acid sequence revealed a relationship with a P. yoelii antigen that has been used successfully in vaccine studies. Thus, this P. falciparum antigen should be considered an additional candidate for assessment in vaccination against the asexual blood-stages of P. falciparum.

Amino Acid Sequence↗

c-FLIPR, a new regulator of death receptor-induced apoptosis.

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-FLIP(L) and c-FLIP(S,) 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-FLIP(R), a death effector domain-only splice variant previously identified on the mRNA level. Impor-/tantly, c-FLIP(R) is recruited to the CD95 (Fas/APO-1) death-inducing signaling complex upon CD95 stimulation. Several properties of c-FLIP(R) are similar to c-FLIP(S): 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-FLIP(R) and similar roles of c-FLIP(R) and c-FLIP(S) isoforms in death receptor-mediated apoptosis.

Antibodies, Monoclonal↗

The potential of proteomics and peptidomics for allergy and asthma research.

Progress in the field of proteomics, the branch of biology that studies the full set of proteins derived from a given genome, is moving fast. Two-dimensional gel electrophoresis (2DG) separation of complex protein mixtures and the subsequent analysis of isolated protein spots by mass spectrometry allow fast and accurate identification of proteins. The comparison of spots from different samples separated on customized 2D gels allows the detection of punctual differences in their mobility and facilitates tracing back differences in protein expression, presence of isoforms, splice variants and posttranslational modifications by mass spectrometry. In spite of significant analytical challenges owing to the high complexity of the proteome and the challenge deriving from the necessity to process huge amounts of raw data generated by mass spectrometric profiling, proteomics has evolved to an indispensable tool in life sciences. A restricted window of the proteome that consists of peptides and small proteins not easily manageable by conventional gel electrophoresis prompted the development of separation methods based on liquid chromatography. This new research field termed peptidomics already contributed, together with proteomics to enlarge our knowledge about biological processes and supported by sophisticated bioinformatics tools, to the discovery of new diagnostic and therapeutic targets. The technological capabilities of biophysical separation, mass spectrometry and bioinformatics form the basis of discovery programs that aim at mining the proteome starting from microgram amounts of protein extracts derived from body fluids and tissues. Proteomics and peptidomics have a great potential to speed up allergy and asthma research, where disease- and tissue-specific samples are easy to obtain.

Asthma↗