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PubMed2000

A carcinoembryonic antigen family cDNA from mouse placenta encoding a protein with a rare domain composition.

The carcinoembryonic antigen (CEA) family comprises many members with pleiotropic functions. Among normal tissues, placenta is characterized by the abundant production of many different kinds of CEA-related proteins, which are apparently important for the maintenance of pregnancy. Using RNA differential display applied to mouse placentae at different gestational days, we have isolated a novel CEA-related cDNA designated as Ceacam11. Ceacam11 cDNA encodes 303 amino acids with a possible signal peptide and two immunoglobulin variable region-like domains. This domain composition is observed only in mouse Cea10/Ceacam10 among the many CEA family members thus far reported. The transcript of Ceacam11 was first detected in the placenta at 12.5 days post-coitus (dpc) and the level increased progressively towards 17.5 dpc. The expression of Ceacam11 appears to be reciprocal to that of Ceacam10, since the Ceacam10 transcripts were detected at 8.5 and 10.5 dpc, but not at 12.5 to 17.5 dpc. In situ hybridization showed that the expression of Ceacam11 was localized to the spongiotrophoblast of the placenta. Except for in the placenta, Ceacam11 transcripts were not detected in any adult tissues examined, including brain, lung, glandular stomach, small intestine, colon, liver, kidney and testis.

Amino Acid Sequence↗
PubMed2001

[Case report: emergency surgery of a giant scrotal hernia].

We present the case of a 61-year-old patient, who had developed a giant scrotal hernia during the course of 30 years. The patient was transferred to our service after stabilization of hemorrhagic shock due to bleeding from varicosis of the giant scrotal sack. The urgent operation was performed by resection of parts of small intestine, colon ascendens, transversum, and the left testis. After 9 days on our intensive care unit and 18 days on our ward the patient was discharged to further ambulatory care. At one year follow up the patient complained about only discrete abdominal problems which could be successfully treated by diet. The operative treatment modalities of so called "giant hernias" as well as possible complication management are discussed.

Aortography↗
PubMed1997

Infant botulism. The first culture-confirmed Danish case.

Infant botulism is caused by intestinal colonization by Clostridium botulinum, C. barati or C. butyricum. Infant botulism has only rarely been reported outside the USA. A 3-month-old boy developed constipation, lethargy, feeding difficulties and descending, severe, symmetric weakness. He was breastfed but had also been fed honey. Supportive care led to complete recovery. The serum was positive for C. botulinum toxin type A-F (mouse toxin neutralization assay). A strain of C. botulinum producing toxin type A and E was identified in the stool. C. botulinum was identified in a jar of honey of the same brand as the honey fed to the patient.

Botulinum Toxins↗
PubMed2003

Foodborne botulism in a six-month-old infant caused by home-canned baby food.

Previously reported cases of botulism in infants have been diagnosed as infant botulism; that is, botulism caused by intestinal colonization by Clostridium botulinum with intraluminal production and absorption of toxin. Foodborne botulism is caused by ingestion of preformed toxin. We describe an unusual case of foodborne botulism in a 6-month-old infant caused by the ingestion of improperly prepared home-canned baby food. This represents the youngest age of onset for foodborne botulism in the United States of which we are aware and illustrates the need to rule out foodborne botulism, which represents a public health emergency, regardless of the patient's age. The diagnosis could have been readily missed or delayed in this case because the weakness was rapidly progressive rather than insidious, as is typical of infant botulism.

Age of Onset↗
PubMed2003

Determination of the transcriptome of Vibrio cholerae during intraintestinal growth and midexponential phase in vitro.

Vibrio cholerae is the etiologic bacterial agent of cholera, a severe diarrheal disease endemic in much of the developing world. The V. cholerae genome contains 3,890 genes distributed between a large and a small chromosome. Although the large chromosome encodes the majority of recognizable gene products and virulence determinants, the small chromosome carries a disproportionate number of hypothetical genes. Thus, little is known about the role of the small chromosome in the biology of this organism or other Vibrio species. We have used the rabbit ileal loop model of V. cholerae infection to obtain in vivo-grown cells under near midexponential conditions in the small-intestinal environment. We compared the global transcriptional pattern of these in vivo-grown cells to those grown to midexponential phase in rich medium under aerobic conditions. Under both conditions, the genes showing the highest levels of expression reside primarily on the large chromosome. However, a shift occurs in vivo that results in many more small chromosomal genes being expressed during growth in the intestine. Our analysis further suggests that nutrient limitation (particularly iron) and anaerobiosis are major stresses experienced by V. cholerae during growth in the rabbit upper intestine. Finally, relative to in vitro growth, the intestinal environment significantly enhanced expression of several virulence genes, including those involved in phenotypes such as motility, chemotaxis, intestinal colonization, and toxin production.

Animals↗
PubMed2000

Identification of a gene at 11q23 encoding a guanine nucleotide exchange factor: evidence for its fusion with MLL in acute myeloid leukemia.

We have identified a gene at 11q23, telomeric to MLL, that encodes a guanine nucleotide exchange factor (GEF). This gene is transcribed into a 9.5-kb mRNA containing a 4.6-kb ORF. By Northern analysis, it was found to be expressed in all human tissues examined including peripheral blood leukocytes, spleen, prostate, testis, ovary, small intestine, colon, and minimally in thymus. Analysis of the predicted protein sequence indicates that it has strong homology to several members of the family of Rho GEFs that includes such oncogenes as Dbl, Vav, Tiam, and Bcr. A patient with primary acute myeloid leukemia (AML) and a karyotype of 51,XY,+8,+19,+3mar was found to have the 5' end of MLL at exon 6 fused in-frame with the 3' end of almost the entire ORF of this gene, which we named LARG for leukemia-associated Rho GEF. Transcriptional orientation of both genes at 11q23 is from centromere to telomere, consistent with other data that suggest the MLL-LARG fusion resulted from an interstitial deletion rather than a balanced translocation. LARG does not appear to have any homology with other MLL partner genes reported thus far. Thus, LARG represents an additional member of the GEF family and a novel MLL fusion partner in acute myeloid leukemia.

Adult↗
PubMed2003

Bacteria-host communication: the language of hormones.

The interbacterial communication system known as quorum sensing (QS) utilizes hormone-like compounds referred to as autoinducers to regulate bacterial gene expression. Enterohemorrhagic Escherichia coli (EHEC) serotype O157:H7 is the agent responsible for outbreaks of bloody diarrhea in several countries. We previously proposed that EHEC uses a QS regulatory system to "sense" that it is within the intestine and activate genes essential for intestinal colonization. The QS system used by EHEC is the LuxS/autoinducer 2 (AI-2) system extensively involved in interspecies communication. The autoinducer AI-2 is a furanosyl borate diester whose synthesis depends on the enzyme LuxS. Here we show that an EHEC luxS mutant, unable to produce the bacterial autoinducer, still responds to a eukaryotic cell signal to activate expression of its virulence genes. We have identified this signal as the hormone epinephrine and show that beta- and alpha-adrenergic antagonists can block the bacterial response to this hormone. Furthermore, using purified and in vitro synthesized AI-2 we showed that AI-2 is not the autoinducer involved in the bacterial signaling. EHEC produces another, previously undescribed autoinducer (AI-3) whose synthesis depends on the presence of LuxS. These results imply a potential cross-communication between the luxS/AI-3 bacterial QS system and the epinephrine host signaling system. Given that eukaryotic cell-to-cell signaling typically occurs through hormones, and that bacterial cell-to-cell signaling occurs through QS, we speculate that QS might be a "language" by which bacteria and host cells communicate.

Bacterial Proteins↗
PubMed1991

ToxR regulates the production of lipoproteins and the expression of serum resistance in Vibrio cholerae.

The genes encoding three lipoproteins of Vibrio cholerae were identified by a combination of DNA sequence analysis and [3H]palmitate labeling of hybrid proteins encoded by TnphoA gene fusions. The expression of these three lipoproteins, TagA, AcfD, and TcpC, was controlled by ToxR, the cholera toxin transcriptional activator. The involvement of other bacterial lipoproteins in conferring resistance to the bactericidal effects of complement prompted us to examine this possibility in V. cholerae. Remarkably, mutations in toxR and tcp genes (including tcpC), involved in the biogenesis of the toxin coregulated pili, rendered V. cholerae about 10(4)-10(6) times more sensitive to the vibriocidal activity of antibody and complement. Since V. cholerae is a noninvasive organism and toxR and tcp mutants are highly defective in intestinal colonization in animals and humans, these results raise the possibility that resistance to a gut-associated, "complement-like" bactericidal activity may be a major virulence determinant of V. cholerae and other enterobacterial species.

Amino Acid Sequence↗
PubMed1995

Molecular cloning, expression, chromosomal assignment, and tissue-specific expression of a murine alpha-(1,3)-fucosyltransferase locus corresponding to the human ELAM-1 ligand fucosyl transferase.

Terminal Fuc alpha 1-3GlcNAc moieties are displayed by mammalian cell surface glycoconjugates in a tissue-specific manner. These oligosaccharides participate in selectin-dependent leukocyte adhesion and have been implicated in adhesive events during murine embryogenesis. Other functions for these molecules remain to be defined, as do the tissue-specific expression patterns of the corresponding alpha-(1-3)-fucosyltransferase (alpha 1-3FT) genes. This report characterizes a murine alpha 1-3FT that shares 77% amino acid sequence identity with human ELAM ligand fucosyltransferase (ELFT, also termed Fuc-TIV). The corresponding gene maps to mouse chromosome 9 in a region of homology with the Fuc-TIV locus on human chromosome 11q. In vitro, the murine alpha 1-3FT can efficiently fucosylate the trisaccharide Gal alpha 1-3Gal beta 1-4GlcNAc (apparent Km of 0.71 mM) to form an unusual tetrasaccharide (Gal alpha 1-3Gal beta 1-4[Fuc alpha 1-3]GlcNAc) described in periimplantation mouse tissues. The enzyme can also form the Lewis x determinant from Gal beta 1-4GlcNAc (Km = 2.05 mM), and the sialyl Lewis x determinant from NeuNAc alpha 2-3Gal beta 1-4GlcNAc (Km = 1.78mM). However, it does not yield sialyl Lewis x determinants when expressed in a mammalian cell line that maintains sialyl Lewis x precursors. Transcripts from this gene accumulate to low levels in hematopoietic organs, but are unexpectedly abundant in epithelia that line the stomach, small intestine, colon, and epididymus. Epithelial cell-specific expression of this gene suggests function(s) in addition to, and distinct from, its proposed role in selectin ligand synthesis.

Amino Acid Sequence↗
PubMed1996

Identification of the mammalian Na,K-ATPase 3 subunit.

We have isolated and characterized cDNA clones encoding the human and rat Na,K-ATPase beta3 subunit isoform. The human cDNA encodes a polypeptide of 279 amino acids that exhibits primary sequence and secondary structure similarities to Na,K-ATPase beta subunit isoforms. Sequence comparisons showed that the human beta3 subunit closely resembles the beta3 subunit of Xenopus laevis (59% amino acid identity) and is less similar to the human Na,K-ATPase beta1 and beta2 subunits (38% and 48% amino acid identity, respectively). By analyzing the segregation of restriction fragment length polymorphisms among recombinant inbred strains of mice, we localized the beta3 subunit gene to murine chromosome 7. Northern blot analysis revealed that the beta3 subunit gene encodes two transcripts that are expressed in a variety of rat tissues including testis, brain, kidney, lung, stomach, small intestine, colon, spleen, and liver. Identification of the mammalian beta3 subunit suggests an even greater potential for Na,K-ATPase isoenzyme diversity than previously realized.

Amino Acid Sequence↗
PubMed1997

Cloning, expression, and characterization of a novel phospholipase D complementary DNA from rat brain.

Phospholipase D (PLD) is implicated in important cellular processes such as signal transduction, membrane trafficking, and mitosis regulation. Recently, cDNA for human PLD1 (hPLD1) was cloned from HeLa cells (Hammond, S. M., Altshuller, Y. M., Sung, T-C., Rudge, S. A., Rose, K., Engebrecht, J., Morris, A. J., and Frohman, M. A. (1995) J. Biol. Chem. 270, 29640-29643). hPLD1 is stimulated by phosphatidylinositol 4,5-bisphosphate and the small GTP-binding protein known as ADP-ribosylation factor 1. Here we report the cloning and characterization of cDNA for a different type of PLD (rat PLD2 (rPLD2)) from rat brain. We synthesized highly degenerate amplimers corresponding to the conserved regions of eukaryote PLDs and performed polymerase chain reaction on a rat brain cDNA library. Using the amplified sequence as the probe, we cloned a rat brain cDNA clone that contained an open reading frame of 933 amino acids with an Mr of 105,992. The deduced amino acid sequence showed significant similarity to hPLD1 with a large deletion in the middle of the sequence. When the sequence was expressed in the fission yeast Schizosaccharomyces pombe, PLD activity was greatly increased. The activity was markedly stimulated by phosphatidylinositol 4, 5-bisphosphate, but not by ADP-ribosylation factor 1 and RhoA. Rat brain cytosol known to stimulate small GTP-binding protein-dependent PLD did not stimulate rPLD2 expressed in S. pombe. The transcript was detected at significant levels in brain, lung, heart, kidney, stomach, small intestine, colon, and testis, but at low levels in thymus, liver, and muscle. Only a negligible level was found in spleen and pancreas. Thus rPLD2 is a novel type of PLD dependent on phosphatidylinositol 4,5-bisphosphate, but not on the small GTP-binding proteins ADP-ribosylation factor 1 and RhoA.

ADP-Ribosylation Factors↗
PubMed2000

Epilysin, a novel human matrix metalloproteinase (MMP-28) expressed in testis and keratinocytes and in response to injury.

We have cloned a new human matrix metalloproteinase (MMP-28, epilysin) from human keratinocyte and testis cDNA libraries. Like most MMPs, epilysin contains a signal sequence, a prodomain with a PRCGVTD sequence, a zinc-binding catalytic domain with an HEIGHTLGLTH sequence, and a hemopexin-like domain. In addition, epilysin has a furin activation sequence (RRKKR) but has no transmembrane sequence. The exon-intron organization and splicing pattern of epilysin differ from that of other MMP genes. It has only 8 exons, and 5 exons are spliced at sites not used by other MMPs. Another novel feature of epilysin is that exon 4 is alternatively spliced to a transcript that does not encode the N-terminal half of the catalytic domain. Northern hybridization of tissue RNA indicated that epilysin is expressed at high levels in testis and at lower levels in lungs, heart, colon, intestine, and brain. RNase protection assay with various cell lines indicated that epilysin was selectively expressed in keratinocytes. Recombinant epilysin degraded casein in a zymography assay, and its proteolytic activity was inhibited by EDTA and by batimastat, a selective MMP inhibitor. Immunohistochemical staining showed expression of epilysin protein in the basal and suprabasal epidermis of intact skin. In injured skin, prominent staining for epilysin was seen in basal keratinocytes both at and some distance from the wound edge, a pattern that is quite distinct from that of other MMPs expressed during tissue repair. These findings suggest that this new MMP functions in several tissues both in tissue homeostasis and in repair.

Adult↗
PubMed2001

Human intelectin is a novel soluble lectin that recognizes galactofuranose in carbohydrate chains of bacterial cell wall.

Galactofuranosyl residues are present in various microorganisms but not in mammals. In this study, we identified a human lectin binding to galactofuranosyl residues and named this protein human intelectin (hIntL). The mature hIntL was a secretory glycoprotein consisting of 295 amino acids and N-linked oligosaccharides, and its basic structural unit was a 120-kDa homotrimer in which 40-kDa polypeptides were bridged by disulfide bonds. The hIntL gene was split into 8 exons on chromosome 1q21.3, and hIntL mRNA was expressed in the heart, small intestine, colon, and thymus. hIntL showed high levels of homology with mouse intelectin, Xenopus laevis cortical granule lectin/oocyte lectin, lamprey serum lectin, and ascidian galactose-specific lectin. These homologues commonly contained no carbohydrate recognition domain, which is a characteristic of C-type lectins, although some of them have been reported as Ca(2+)-dependent lectins. Recombinant hIntL revealed affinities to d-pentoses and a d-galactofuranosyl residue in the presence of Ca(2+), and recognized the bacterial arabinogalactan of Nocardia containing d-galactofuranosyl residues. These results suggested that hIntL is a new type lectin recognizing galactofuranose, and that hIntL plays a role in the recognition of bacteria-specific components in the host.

Amino Acid Sequence↗
PubMed2002

Characterization of the second type of human beta-galactoside alpha 2,6-sialyltransferase (ST6Gal II), which sialylates Galbeta 1,4GlcNAc structures on oligosaccharides preferentially. Genomic analysis of human sialyltransferase genes.

A novel member of the human beta-galactoside alpha2,6-sialyltransferase (ST6Gal) family, designated ST6Gal II, was identified by BLAST analysis of expressed sequence tags and genomic sequences. The sequence of ST6Gal II encoded a protein of 529 amino acids, and it showed 48.9% amino acid sequence identity with human ST6Gal I. Recombinant ST6Gal II exhibited alpha2,6-sialyltransferase activity toward oligosaccharides that have the Galbeta1,4GlcNAc sequence at the nonreducing end of their carbohydrate groups, but it exhibited relatively low and no activities toward some glycoproteins and glycolipids, respectively. It is concluded that ST6Gal II is an oligosaccharide-specific enzyme compared with ST6Gal I, which exhibits broad substrate specificities, and is mainly involved in the synthesis of sialyloligosaccharides. The expression of the ST6Gal II gene was significantly detected by reverse transcription PCR in small intestine, colon, and fetal brain, whereas the ST6Gal I gene was ubiquitously expressed, and its expression levels were much higher than those of the ST6Gal II gene. The ST6Gal I gene was also expressed in all tumors examined, but no expression was observed for the ST6Gal II gene in these tumors. The ST6Gal II gene is located on chromosome 2 (2q11.2-q12.1), and it spans over 85 kb of human genomic DNA consisting of at least eight exons and shares a similar genomic structure with the ST6Gal I gene. In this paper, we have shown that ST6Gal I, which has been known as the sole member of the ST6Gal family, also has the counterpart enzyme (ST6Gal II) like other sialyltransferases.

Acetylglucosamine↗
PubMed2003

Identification and characterization of a novel RF-amide peptide ligand for orphan G-protein-coupled receptor SP9155.

Orphan G-protein-coupled receptors are a large class of receptors whose cognate ligands are unknown. SP9155 (also referred to as AQ27 and GPR103) is an orphan G-protein-coupled receptor originally cloned from a human brain cDNA library. SP9155 was found to be predominantly expressed in brain, heart, kidney, retina, and testis. Phylogenetic analysis shows that SP9155 shares high homology with Orexin, NPFF, and cholecystokinin (CCK) receptors, but identification of the endogenous ligand for SP9155 has not been reported. In this study, we have used a novel method to predict peptides from genome data bases. From these predicted peptides, a novel RF-amide peptide, P52 was shown to selectively activate SP9155-transfected cells. We subsequently cloned the precursor gene of the P52 ligand and characterized the activity of other possible peptides encoded by the precursor. This revealed an extended peptide, P518, which exhibited high affinity for SP9155 (EC50 = 7 nm). mRNA expression analysis revealed that the peptide P518 precursor gene is predominantly expressed in various brain regions, coronary arteries, thyroid and parathyroid glands, large intestine, colon, bladder, testes, and prostate. These results indicate the existence of a novel RF-amide neuroendocrine peptide system, and suggest that SP9155 is likely the relevant G-protein-coupled receptor for this peptide.

Algorithms↗
PubMed2004

Cloning and characterization of a novel human RNA binding protein gene PNO1.

Present work reported the cloning and characterization of a human novel RNA binding gene Partner of NOB1 (PNO1), with a length of 1637bp and a putative open reading frame of 759 bp, isolated from human kidney. It is composed of seven exons and is localized on chromosome 2p14. Western blot showed that the molecular weight of PNO1 is about 35kDa. RT-PCR results in 16 human tissues indicated that PNO1 is expressed mainly in liver, lung, spleen and kidney, slightly in thymus, testis, ovary, respectively, but not in heart, brain, skeletal muscle, placenta, pancreas, prostate, small intestine, colon and peripheral blood leukocytes. GFP fusion expression in mammalian cells exhibited its localization in the nucleus, especially in nucleoli. Subcellular localization of thirteen GFP fusion PNO1 deletion proteins showed that the region of 92-230 aa is solely responsible for its nucleolar retention, and KH domain alone is not sufficient for nucleolar retention. The PNO1 family shows significant conservation in both eukaryotes and prokaryotes.

Amino Acid Sequence↗
PubMedDate not supplied

Evidence that iron-overload promotes 7,12-dimethylbenz(a)anthracene- induced skin tumorigenesis in mice.

Iron overload is known to occur in West European and American populations due to the consumption of an iron-rich diet. There are also genetic disorders which lead to body iron overload. It has been shown that iron overload predisposes humans to an increased risk of cancer. In experimental animals, iron overload is known to enhance intestinal, colon, hepatic, pulmonary and mammary carcinogenesis. However, the mechanism by which iron overload enhances chemically-induced carcinogenesis is not known. In this study, we show that iron overload acts as a mild tumor promoter in mouse skin. Female albino swiss mice were given 1 mg iron/mouse parenterally for 2 weeks to induce iron overload. These animals showed a three-fold increase in cutaneous iron concentration as compared to normal mice. Tumors were initiated by topically applying 7,12-dimethylbenz(a)anthracene (DMBA). Appearance of the first tumor (latency period), percent tumor incidence and number of tumors/mouse were recorded. When compared to the control group, iron overload mice showed an increased incidence of tumors, from 25%-55% by week 20, and tumors appeared 4 weeks earlier. The number of tumors per mouse was four-fold higher in the iron overload group. The induction of cutaneous ornithine decarboxylase (ODC) activity and [3H]thymidine incorporation in cutaneous DNA were higher in iron overload groups as compared to normal control animals. Similar to other oxidant tumor promoters, iron overload enhanced cutaneous lipid peroxidation and xanthine oxidase activity and decreased catalase activity. Our results indicate that iron overload exerts a mild tumor promoting activity in mouse skin. Our data also show that oxidative stress generated by iron overload plays an important role in the augmentation of cutaneous tumorigenesis. These data may also have implications for the enhanced risk of cancer-induction following UVB exposure of human populations with iron overload.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1994

Expression and polarized targeting of a rab3 isoform in epithelial cells.

Pathways of polarized membrane traffic in epithelial tissues serve a variety of functions, including the generation of epithelial polarity and the regulation of vectorial transport. We have identified a candidate regulator of polarized membrane traffic in epithelial cells (i.e., rab3B), which is a member of the rab family of membrane traffic regulators. Rab3B is highly homologous to a brain-specific rab3 isoform (rab3A) that targets in a polarized fashion to the presynaptic nerve terminal, where it probably regulates exocytosis. The coding region for human rab3B was cloned from epithelial mRNA using a reverse-transcription polymerase chain reaction strategy. This cDNA clone hybridized to a single mRNA species in Northern blots of poly(A)+ RNA isolated from epithelial cell lines. A rab3B-specific antibody that was raised against recombinant fusion protein recognized a 25-kD band in immunoblots of cell lysates prepared from cultured epithelial cells (e.g., T84 and HT29-CL19A), but not from a variety of nonepithelial cells (e.g., PC12 neuroendocrine cells). Immunofluorescence analysis confirmed that rab3B protein is preferentially expressed in cultured epithelial cells as well as in a number of native epithelial tissues, including liver, small intestine, colon, and distal nephron. Rab3B localized to the apical pole very near the tight junctions between adjacent epithelial cells within all of these cell lines and native epithelial tissues, as determined by immunofluorescence and immunoelectron microscopic analysis. Moreover, this pattern of intracellular targeting was regulated by cell contact; namely, rab3B was reversibly retrieved from the cell periphery as epithelial cell contact was inhibited by reducing the extracellular Ca2+ concentration. Our results indicate that neurons and epithelial cells express homologous rab3 isoforms that target in a polarized fashion within their respective tissues. The pattern and regulation of rab3B targeting in epithelial cells implicates this monomeric GTPase as a candidate regulator of apical and/or junctional protein traffic in epithelial tissues.

Animals↗