scholarly journals Ks1, an epithelial cell-specific gene, responds to early signals of head formation in Hydra

Development ◽  
1994 ◽  
Vol 120 (9) ◽  
pp. 2511-2517 ◽  
Author(s):  
R. Weinziger ◽  
L.M. Salgado ◽  
C.N. David ◽  
T.C. Bosch
Keyword(s):  
Epithelial Cell ◽  
Epithelial Cells ◽  
Signal Sequence ◽  
Sequence Similarity ◽  
Specific Gene ◽  
Acid Protein ◽  
Head Formation ◽  
Sequence Elements ◽  
Messenger System ◽  
Amino Acid Protein

As a molecular marker for head specification in Hydra, we have cloned an epithelial cell-specific gene which responds to early signals of head formation. The gene, designated ks1, encodes a 217-amino acid protein lacking significant sequence similarity to any known protein. KS1 contains a N-terminal signal sequence and is rich in charged residues which are clustered in several domains. ks1 is expressed in tentacle-specific epithelial cells (battery cells) as well as in a small fraction of ectodermal epithelial cells in the gastric region subjacent to the tentacles. Treatment with the protein kinase C activator 12-O-tetradecanoylphorbol-13-acetate (TPA) causes a rapid increase in the level of ks1 mRNA in head-specific epithelial cells and also induces ectopic ks1 expression in cells of the gastric region. Sequence elements in the 5′-flanking region of ks1 that are related to TPA-responsive elements may mediate the TPA inducibility of ks1 expression. The pattern of expression of ks1 suggests that a ligand-activated diacyglycerol second messenger system is involved in head-specific differentiation.

scholarly journals A Dual Role for Oncostatin M Signaling in the Differentiation and Death of Mammary Epithelial Cells in Vivo

2008 ◽  
Vol 22 (12) ◽  
pp. 2677-2688 ◽  
Author(s):  
Paul G. Tiffen ◽  
Nader Omidvar ◽  
Nuria Marquez-Almuina ◽  
Dawn Croston ◽  
Christine J. Watson ◽  
...  
Keyword(s):  
Gene Expression ◽  
Epithelial Cell ◽  
Epithelial Cells ◽  
Mammary Epithelial Cells ◽  
Mammary Epithelial ◽  
Oncostatin M ◽  
Specific Gene ◽  
Mammary Involution

Abstract Recent studies in breast cancer cell lines have shown that oncostatin M (OSM) not only inhibits proliferation but also promotes cell detachment and enhances cell motility. In this study, we have looked at the role of OSM signaling in nontransformed mouse mammary epithelial cells in vitro using the KIM-2 mammary epithelial cell line and in vivo using OSM receptor (OSMR)-deficient mice. OSM and its receptor were up-regulated approximately 2 d after the onset of postlactational mammary regression, in response to leukemia inhibitory factor (LIF)-induced signal transducer and activator of transcription-3 (STAT3). This resulted in sustained STAT3 activity, increased epithelial apoptosis, and enhanced clearance of epithelial structures during the remodeling phase of mammary involution. Concurrently, OSM signaling precipitated the dephosphorylation of STAT5 and repressed expression of the milk protein genes β-casein and whey acidic protein (WAP). Similarly, during pregnancy, OSM signaling suppressed β-casein and WAP gene expression. In vitro, OSM but not LIF persistently down-regulated phosphorylated (p)-STAT5, even in the continued presence of prolactin. OSM also promoted the expression of metalloproteinases MMP3, MMP12, and MMP14, which, in vitro, were responsible for OSM-specific apoptosis. Thus, the sequential activation of IL-6-related cytokines during mammary involution culminates in an OSM-dependent repression of epithelial-specific gene expression and the potentiation of epithelial cell extinction mediated, at least in part, by the reciprocal regulation of p-STAT5 and p-STAT3.

scholarly journals Cloning and Characterization of the DNA Region Responsible for Megacin A-216 Production in Bacillus megaterium 216

2008 ◽  
Vol 190 (19) ◽  
pp. 6448-6457 ◽  
Author(s):  
Antal Kiss ◽  
Gabriella Balikó ◽  
Attila Csorba ◽  
Tungalag Chuluunbaatar ◽  
Katalin F. Medzihradszky ◽  
...  
Keyword(s):  
Amino Acid ◽  
Bacillus Megaterium ◽  
Sequence Similarity ◽  
Bacterial Species ◽  
Biologically Active ◽  
Mass Spectrometry Analysis ◽  
High Sequence Similarity ◽  
Spectrometry Analysis ◽  
Acid Protein ◽  
Amino Acid Protein

ABSTRACT Upon induction, Bacillus megaterium 216 produces the bacteriocin megacin A-216, which leads to lysis of the producer cell and kills B. megaterium and a few other bacterial species. The DNA region responsible for megacinogeny was cloned in B. megaterium. The nucleotide sequence of a 5,494-bp-long subfragment was determined, and the function of the genes on this fragment was studied by generating deletions and analyzing their effects on MegA phenotypes. An open reading frame (ORF) encoding a 293-amino-acid protein was identified as the gene (megA) coding for megacin A-216. BLAST searches detected sequence similarity between megacin A-216 and proteins with phospholipase A2 activity. Purified biologically active megacin A-216 preparations contained three proteins. Mass spectrometry analysis showed that the largest protein is the full-length translation product of the megA gene, whereas the two shorter proteins are fragments of the long protein created by cleavage between Gln-185 and Val-186. The molecular masses of the three polypeptides are 32,855, 21,018, and 11,855 Da, respectively. Comparison of different megacin preparations suggests that the intact chain as well as the two combined fragments can form biologically active megacin. An ORF located next to the megA gene and encoding a 91-amino-acid protein was shown to be responsible for the relative immunity displayed by the producer strain against megacin A-216. Besides the megA gene, at least two other genes, including a gene encoding a 188-amino-acid protein sharing high sequence similarity with RNA polymerase sigma factors, were shown to be required for induction of megacin A-216 expression.

scholarly journals Characterization of an Endo-β-1,6-Galactanase from Streptomyces avermitilis NBRC14893

2008 ◽  
Vol 74 (8) ◽  
pp. 2379-2383 ◽  
Author(s):  
Hitomi Ichinose ◽  
Toshihisa Kotake ◽  
Yoichi Tsumuraya ◽  
Satoshi Kaneko
Keyword(s):  
Signal Sequence ◽  
Recombinant Enzyme ◽  
Streptomyces Avermitilis ◽  
Glycoside Hydrolase Family ◽  
Reading Frame ◽  
Secretion Signal ◽  
Acid Protein ◽  
Hydrolysis Of ◽  
Amino Acid Protein

ABSTRACT The putative endo-β-1,6-galactanase gene from Streptomyces avermitilis was cloned and expressed in Escherichia coli, and the enzymatic properties of the recombinant enzyme were characterized. The gene consisted of a 1,476-bp open reading frame and encoded a 491-amino-acid protein, comprising an N-terminal secretion signal sequence and glycoside hydrolase family 5 catalytic module. The recombinant enzyme, Sa1,6Gal5A, catalyzed the hydrolysis of β-1,6-linked galactosyl linkages of oligosaccharides and polysaccharides. The enzyme produced galactose and a range of β-1,6-linked galacto-oligosaccharides, predominantly β-1,6-galactobiose, from β-1,6-galactan chains. There was a synergistic effect between the enzyme and Sa1,3Gal43A in degrading tomato arabinogalactan proteins. These results suggest that Sa1,6Gal5A is the first identified endo-β-1,6-galactanase from a prokaryote.

scholarly journals The Streptococcus pneumoniaeBeta-Galactosidase Is a Surface Protein

2000 ◽  
Vol 182 (20) ◽  
pp. 5919-5921 ◽  
Author(s):  
Dorothea Zähner ◽  
Regine Hakenbeck
Keyword(s):  
Amino Acid ◽  
Signal Sequence ◽  
Cell Envelope ◽  
Glycosyl Hydrolase ◽  
Surface Protein ◽  
Gram Positive Bacteria ◽  
Acid Protein ◽  
Associated Proteins ◽  
Hydrolase Family ◽  
Amino Acid Protein

ABSTRACT The β-galactosidase gene of Streptococcus pneumoniae,bgaA, encodes a putative 2,235-amino-acid protein with the two amino acid motifs characteristic of the glycosyl hydrolase family of proteins. In addition, an N-terminal signal sequence and a C-terminal LPXTG motif typical of surface-associated proteins of gram-positive bacteria are present. Trypsin treatment of cells resulted in solubilization of the enzyme, documenting that it is associated with the cell envelope. In order to obtain defined mutants suitable forlacZ reporter experiments, the bgaA gene was disrupted, resulting in a complete absence of endogenous β-galactosidase activity. The results are consistent with β-galactosidase being a surface protein that seems not to be involved in lactose metabolism but that may play a role during pathogenesis.

scholarly journals Tn5706, a Transposon-Like Element fromPasteurella multocida Mediating Tetracycline Resistance

1998 ◽  
Vol 42 (8) ◽  
pp. 2116-2118 ◽  
Author(s):  
Corinna Kehrenberg ◽  
Christiane Werckenthin ◽  
Stefan Schwarz
Keyword(s):  
Insertion Sequence ◽  
Pasteurella Multocida ◽  
Tetracycline Resistance ◽  
Gram Positive Bacteria ◽  
Acid Protein ◽  
Sequence Elements ◽  
Insertion Elements ◽  
Insertion Sequence Elements ◽  
Reading Frames ◽  
Amino Acid Protein

ABSTRACT The 4,378-bp putative tetracycline resistance transposon Tn5706 of Pasteurella multocida consists of an internal tet(H)-tetRresistance gene region which is flanked by almost identical insertion elements, IS1596 and IS1597. Two reading frames for proteins of 70 and 228 amino acids were detected in each of these insertion sequence elements. The 228-amino-acid protein revealed homology to transposase proteins of gram-positive bacteria.

scholarly journals Expression of Mycobacteriophage Ms6 Lysis Genes Is Driven by Two σ70-Like Promoters and Is Dependent on a Transcription Termination Signal Present in the Leader RNA

2002 ◽  
Vol 184 (11) ◽  
pp. 3034-3043 ◽  
Author(s):  
Miguel Garcia ◽  
Madalena Pimentel ◽  
José Moniz-Pereira
Keyword(s):  
Amino Acid ◽  
Unknown Function ◽  
Promoter Region ◽  
Sequence Similarity ◽  
Transcription Termination ◽  
Cell Lysis ◽  
Leader Sequence ◽  
Significant Similarity ◽  
Acid Protein ◽  
Amino Acid Protein

ABSTRACT A mycobacteriophage Ms6 strong promoter region (Plys ) was isolated by using transcriptional fusions with the lacZ reporter gene. Two tandem σ70-like promoter sequences (P1 and P2) were found in this region. DNA sequencing of the promoter downstream region revealed a 214-bp leader sequence followed by five adjacent coding regions of 231 bp (ORF1), 1,152 bp (ORF2), 996 bp (ORF3), 231 bp (ORF4), and 372 (ORF5). ORF1 has the potential to encode a 77-amino-acid protein which revealed similarity to mycobacteriophage TM4 gp90, a predicted protein with unknown function. ORF2 encodes a 384-amino-acid protein which is related to several bacteriophage amidases. This protein induced cell lysis upon addition of chloroform, confirming its mureinolytic activity. ORF3 encodes a 332-amino-acid protein which is related to TM4 gp30, a protein with sequence similarity to amidases. ORF4 encodes a 77-amino-acid holin-like protein with significant similarity to the holin of Lactococcus lactis r1t bacteriophage. ORF5 encodes a 124-amino-acid protein which is related to mycobacteriophage L5 gp30, a protein with unknown function. These data indicate that the promoter region Plys drives the transcription of the Ms6 lysis genes. An intrinsic transcription termination signal was identified in the leader sequence. Experiments using lacZ fusions showed that β-galactosidase synthesis is inhibited when this transcription termination signal is present in the leader sequence. In conclusion, mycobacteriophage Ms6 cell lysis genes are expressed by their own promoter region, independently of virion structure and assembly protein genes. Moreover, an antitermination mechanism might be involved in their transcription regulation.

Expression of a Drosophila mRNA is under circadian clock control during pupation

Development ◽  
1989 ◽  
Vol 107 (4) ◽  
pp. 869-880 ◽  
Author(s):  
L.J. Lorenz ◽  
J.C. Hall ◽  
M. Rosbash
Keyword(s):  
Circadian Clock ◽  
Signal Sequence ◽  
Rapid Decay ◽  
Cdna Sequences ◽  
Stage Of Development ◽  
Acid Protein ◽  
Conceptual Translation ◽  
Per Gene ◽  
Amino Acid Protein

Rhythmic eclosion of Drosophila adults requires per gene function. We have found that a previously identified 0.9 kb RNA transcribed from DNA adjacent to per becomes abundantly expressed during pupation, just prior to eclosion. The daily synchronized emergence of young adults, coupled with a subsequent rapid decay of the transcript, is responsible for what previously appeared to be cycling of the 0.9 kb RNA in adults. In situ hybridization analyses localize the 0.9 kb transcript to the epidermis of newly eclosed adults. Conceptual translation of genomic DNA and cDNA sequences predicts that the 0.9 kb transcript produces a 261 amino acid protein containing a putative signal sequence for membrane transport at its amino terminus. Pupae that reach the same stage of development at slightly different times of day show a subsequent synchronized rise in 0.9 kb RNA levels, indicating that the expression of this transcript is under circadian clock control.

scholarly journals Direct Sulfhydrylation for Methionine Biosynthesis in Leptospira meyeri

1998 ◽  
Vol 180 (2) ◽  
pp. 250-255 ◽  
Author(s):  
J. Belfaiza ◽  
A. Martel ◽  
D. Margarita ◽  
I. Saint Girons
Keyword(s):  
Amino Acid ◽  
Sequence Similarity ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Methionine Biosynthesis ◽  
T7 Promoter ◽  
Acid Protein ◽  
Transsulfuration Pathway ◽  
High Degree ◽  
Amino Acid Protein

ABSTRACT A gene library of the Leptospira meyeri serovar semaranga strain Veldrat S.173 DNA has been constructed in a mobilizable cosmid with inserts of up to 40 kb. It was demonstrated that a Leptospira DNA fragment carrying metYcomplemented Escherichia coli strains carrying mutations inmetB. The latter gene encodes cystathionine γ-synthase, an enzyme which catalyzes the second step of the methionine biosynthetic pathway. The metY gene is 1,304 bp long and encodes a 443-amino-acid protein with a molecular mass of 45 kDa as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The deduced amino acid sequence of theLeptospira metY product has a high degree of similarity to those of O-acetylhomoserine sulfhydrylases fromAspergillus nidulans and Saccharomyces cerevisiae. A lower degree of sequence similarity was also found with bacterial cystathionine γ-synthase. The L. meyeri metY gene was overexpressed under the control of the T7 promoter. MetY exhibits an O-acetylhomoserine sulfhydrylase activity. Genetic, enzymatic, and physiological studies reveal that the transsulfuration pathway via cystathionine does not exist in L. meyeri, in contrast to the situation found for fungi and some bacteria. Our results indicate, therefore, that the L. meyeri MetY enzyme is able to perform direct sulfhydrylation for methionine biosynthesis by using O-acetylhomoserine as a substrate.

Electron Microscopic Study of the Epithelium of the Seminal Vesicle of Aging Rats

1974 ◽  
Vol 32 ◽  
pp. 138-139
Author(s):  
V. F. Allison ◽  
G. C. Fink ◽  
G. W. Cearley
Keyword(s):  
Cell Growth ◽  
Epithelial Cell ◽  
Epithelial Cells ◽  
Seminal Vesicle ◽  
Seminal Vesicles ◽  
Epithelial Layer ◽  
Epithelial Hyperplasia ◽  
Electron Microscopic ◽  
Aging Rats ◽  
Pseudostratified Epithelium

It is well known that epithelial hyperplasia (benign hypertrophy) is common in the aging prostate of dogs and man. In contrast, little evidence is available for abnormal epithelial cell growth in seminal vesicles of aging animals. Recently, enlarged seminal vesicles were reported in senescent mice, however, that enlargement resulted from increased storage of secretion in the lumen and occurred concomitant to epithelial hypoplasia in that species.The present study is concerned with electron microscopic observations of changes occurring in the pseudostratified epithelium of the seminal vescles of aging rats. Special attention is given to certain non-epithelial cells which have entered the epithelial layer.

Intranuclear Crystals in Regenerating Canine Kidneys

1973 ◽  
Vol 31 ◽  
pp. 412-413
Author(s):  
D.G. Osborne ◽  
L.J. McCormack ◽  
M.O. Magnusson ◽  
W.S. Kiser
Keyword(s):  
Epithelial Cell ◽  
Epithelial Cells ◽  
Tubular Epithelial Cell ◽  
Tubular Epithelial Cells ◽  
Cell Nuclei ◽  
Crystalline Structures ◽  
Small Crystals ◽  
Membrane Bound

During a project in which regenerative changes were studied in autotransplanted canine kidneys, intranuclear crystals were seen in a small number of tubular epithelial cells. These crystalline structures were seen in the control specimens and also in regenerating specimens; the main differences being in size and number of them. The control specimens showed a few tubular epithelial cell nuclei almost completely occupied by large crystals that were not membrane bound. Subsequent follow-up biopsies of the same kidneys contained similar intranuclear crystals but of a much smaller size. Some of these nuclei contained several small crystals. The small crystals occurred at one week following transplantation and were seen even four weeks following transplantation. As time passed, the small crystals appeared to fuse to form larger crystals.

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