scholarly journals Multiple Features Contribute to the Use of the Immunoglobulin M Secretion-Specific Poly(A) Signal but Are Not Required for Developmental Regulation

2006 ◽  
Vol 26 (18) ◽  
pp. 6762-6771 ◽  
Author(s):  
Martha L. Peterson ◽  
Gina L. Bingham ◽  
Clarissa Cowan
Keyword(s):  
Developmental Regulation ◽  
Immunoglobulin M ◽  
Wild Type ◽  
Developmentally Regulated ◽  
Multiple Features ◽  
Direct Competition ◽  
Splice Reaction ◽  
Signal Use ◽  
Signal Regulation ◽  
Made In

ABSTRACT The secretory-specific poly(A) signal (μs) of the immunoglobulin μ gene plays a central role in regulating alternative RNA processing to produce RNAs that encode membrane-associated and secreted immunoglobulins. This poly(A) signal is in direct competition with a splice reaction, and regulation requires that these two reaction efficiencies be balanced. The μs poly(A) signal has several unique sequence features that may contribute to its strength and regulation. Site-directed mutations and small internal deletions made in the intact μ gene show that an extensive AU/A-rich sequence surrounding AAUAAA enhances signal use and that, of the two potential downstream GU-rich elements, both of which appear suboptimally located, only the proximal GU-rich sequence contributes substantially to use of this signal. A GU-rich sequence placed at a more standard location did not improve μs poly(A) signal use. All μ genes tested that contained modified μs poly(A) signals were developmentally regulated, indicating that the GU-rich sequences, the sequences between them previously identified as suboptimal U1A binding sites, and an upstream suboptimal U1A site do not contribute to μ mRNA processing regulation. Expression of wild-type and modified μ genes in HeLa cells overexpressing U1A also failed to demonstrate that U1A contributes to μs poly(A) signal regulation.

scholarly journals Developmental Regulation of Transcription ofwhiE, a Locus Specifying the Polyketide Spore Pigment in Streptomyces coelicolor A3(2)

1998 ◽  
Vol 180 (9) ◽  
pp. 2515-2521 ◽  
Author(s):  
Gabriella H. Kelemen ◽  
Paul Brian ◽  
Klas Flärdh ◽  
Leony Chamberlin ◽  
Keith F. Chater ◽  
...  
Keyword(s):  
Biosynthetic Pathway ◽  
Developmental Regulation ◽  
Streptomyces Coelicolor ◽  
Colony Development ◽  
Regulation Of Transcription ◽  
Wild Type ◽  
Developmentally Regulated ◽  
Complex Locus ◽  
Spore Pigment

ABSTRACT whiE is a complex locus that specifies the polyketide spore pigment in Streptomyces coelicolor A3(2). Two divergently oriented promoters, whiEP1 andwhiEP2, were identified in the whiE gene cluster, and their activities were analyzed during colony development in wild-type and sporulation-deficient strains. Both promoters were developmentally regulated; whiEP1 and whiEP2transcripts were detected transiently at approximately the time when sporulation septa were observed in the aerial hyphae, and transcription from both promoters depended on each of the six known “early”whi genes required for sporulation septum formation (whiA, -B, -G, -H, -I, and -J). Mutation of the late sporulation-specific sigma factor gene, sigF, had no effect on the activity of whiEP1 but blocked transcription fromwhiEP2. However, ςF-containing holoenzyme was not sufficient to direct transcription of whiEP2 in vitro. The whiEP2 promoter controls expression of whiEORFVIII, encoding a putative flavin adenine dinucleotide-dependent hydroxylase that catalyzes a late tailoring step in the spore pigment biosynthetic pathway. Disruption of whiE ORFVIII causes a change in spore color, from grey to greenish (T.-W. Yu and D. A. Hopwood, Microbiology 141:2779–2791, 1995). Consistent with these observations, construction of a sigF null mutant ofS. coelicolor M145 caused the same change in spore color, showing that disruption of sigF in S. coelicolor changes the nature of the spore pigment rather than preventing its synthesis altogether.

scholarly journals Identification and developmental regulation of a neuron-specific subunit of cytoplasmic dynein.

1996 ◽  
Vol 7 (2) ◽  
pp. 331-343 ◽  
Author(s):  
K K Pfister ◽  
M W Salata ◽  
J F Dillman ◽  
E Torre ◽  
R J Lye
Keyword(s):  
Axonal Transport ◽  
Developmental Regulation ◽  
Cytoplasmic Dynein ◽  
Retrograde Axonal Transport ◽  
Protein Isoforms ◽  
Cultured Neurons ◽  
Developmentally Regulated ◽  
Time Period ◽  
Intermediate Chains

Cytoplasmic dynein is the microtubule minus-end-directed motor for the retrograde axonal transport of membranous organelles. Because of its similarity to the intermediate chains of flagellar dynein, the 74-kDa intermediate chain (IC74) subunit of dynein is thought to be involved in binding dynein to its membranous organelle cargo. Previously, we identified six isoforms of the IC74 cytoplasmic dynein subunit in the brain. We further demonstrated that cultured glia and neurons expressed different dynein IC74 isoforms and phospho-isoforms. Two isoforms were observed when dynein from glia was analyzed. When dynein from cultured neurons was analyzed, six IC74 isoforms were observed, although the relative amounts of the dynein isoforms from cultured neurons differed from those found in dynein from brain. To better understand the role of the neuronal IC74 isoforms and identify neuron-specific IC74 dynein subunits, the expression of the IC74 protein isoforms and mRNAs of various tissues were compared. As a result of this comparison, the identity of each of the isoform spots observed on two-dimensional gels was correlated with the products of each of the IC74 mRNAs. We also found that between the fifteenth day of gestation (E15) and the fifth day after birth (P5), the relative expression of the IC74 protein isoforms changes, demonstrating that the expression of IC74 isoforms is developmentally regulated in brain. During this time period, there is relatively little change in the abundance of the various IC74 mRNAs. The E15 to P5 time period is one of rapid process extension and initial pattern formation in the rat brain. This result indicates that the changes in neuronal IC74 isoforms coincide with neuronal differentiation, in particular the extension of processes. This suggests a role for the neuronal IC74 isoforms in the establishment or regulation of retrograde axonal transport.

scholarly journals Functional Promiscuity of Gene Regulation by Serpentine Receptors in Dictyostelium discoideum

1998 ◽  
Vol 18 (10) ◽  
pp. 5744-5749 ◽  
Author(s):  
Irene Verkerke-Van Wijk ◽  
Ji-Yun Kim ◽  
Raymond Brandt ◽  
Peter N. Devreotes ◽  
Pauline Schaap
Keyword(s):  
Gene Expression ◽  
Cell Fate ◽  
Dictyostelium Discoideum ◽  
Developmental Regulation ◽  
Mutant Cell ◽  
Gene Induction ◽  
Specific Gene ◽  
Wild Type ◽  
Animal Development ◽  
Camp Stimulation

ABSTRACT Serpentine receptors such as smoothened and frizzled play important roles in cell fate determination during animal development. InDictyostelium discoideum, four serpentine cyclic AMP (cAMP) receptors (cARs) regulate expression of multiple classes of developmental genes. To understand their function, it is essential to know whether each cAR is coupled to a specific gene regulatory pathway or whether specificity results from the different developmental regulation of individual cARs. To distinguish between these possibilities, we measured gene induction in car1 car3 double mutant cell lines that express equal levels of either cAR1, cAR2, or cAR3 under a constitutive promoter. We found that all cARs efficiently mediate both aggregative gene induction by cAMP pulses and induction of postaggregative and prespore genes by persistent cAMP stimulation. Two exceptions to this functional promiscuity were observed. (i) Only cAR1 can mediate adenosine inhibition of cAMP-induced prespore gene expression, a phenomenon that was found earlier in wild-type cells. cAR1’s mediation of adenosine inhibition suggests that cAR1 normally mediates prespore gene induction. (ii) Only cAR2 allows entry into the prestalk pathway. Prestalk gene expression is induced by differentiation-inducing factor (DIF) but only after cells have been prestimulated with cAMP. We found that DIF-induced prestalk gene expression is 10 times higher in constitutive cAR2 expressors than in constitutive cAR1 or cAR3 expressors (which still have endogenous cAR2), suggesting that cAR2 mediates induction of DIF competence. Since in wild-type slugs cAR2 is expressed only in anterior cells, this could explain the so far puzzling observations that prestalk cells differentiate at the anterior region but that DIF levels are actually higher at the posterior region. After the initial induction of DIF competence, cAMP becomes a repressor of prestalk gene expression. This function can again be mediated by cAR1, cAR2, and cAR3.

scholarly journals Rat lung lectin synthesis, degradation and activation. Developmental regulation and modulation by dexamethasone

1987 ◽  
Vol 245 (3) ◽  
pp. 683-690 ◽  
Author(s):  
L B Clerch ◽  
P L Whitney ◽  
D Massaro
Keyword(s):  
Binding Protein ◽  
Developmental Regulation ◽  
Fold Increase ◽  
Rat Lung ◽  
Absolute Rate ◽  
Lectin Activity ◽  
Developmentally Regulated ◽  
Rat Pups ◽  
The Absolute

Soluble lectins are widely distributed cell-agglutinating proteins. Their activity is developmentally regulated in several tissues, including the lung, but virtually nothing is known about the mechanisms of the developmental regulation or the turnover of these proteins. We studied mechanisms that might be responsible for the developmentally regulated changes in the activity of a lectin (beta-galactoside-binding protein) found in the lung, and determined if its activity or turnover could be modulated by treatment of rat pups with a glucocorticosteroid hormone (dexamethasone). Our studies on the activity and turnover of the lectin indicated that the peak of lectin activity (units/mg of protein) that occurred at age 12 days appeared to be brought about by two means: an increase in the activity of the lectin molecule itself (units/micrograms of lectin) that occurred at age 8 days, and 1.5-fold increase in the absolute rate of lectin synthesis at age 11 days. The decline in lectin activity was associated with a decrease in its rate of synthesis, return to the baseline extent of activation, and an increased rate of degradation. Treatment of rat pups with dexamethasone diminished the peak of lectin activity (units/mg of protein) by about 25%. This effect of dexamethasone was due, at least in part, to the complete prevention of activation of the lectin molecule (units/micrograms of lectin) and a premature increase in the rate of lectin degradation. Perhaps the normal fall in lectin activity after age 11 days is caused by mechanisms induced by the increase in serum corticosteroid that occurs at that age.

scholarly journals The Valine Anticodon and Valylatability of Peanut Clump Virus RNAs Are Not Essential but Provide a Modest Competitive Advantage in Plants

2000 ◽  
Vol 74 (18) ◽  
pp. 8720-8725 ◽  
Author(s):  
Daiki Matsuda ◽  
Patrice Dunoyer ◽  
Odile Hemmer ◽  
Christiane Fritsch ◽  
Theo W. Dreher
Keyword(s):  
Sequence Analysis ◽  
Nicotiana Benthamiana ◽  
General Characteristic ◽  
Wild Type ◽  
Genomic Rnas ◽  
Viral Rnas ◽  
Fold Reduction ◽  
Direct Competition

ABSTRACT The role of valine aminoacylation of the two genomic RNAs ofPeanut clump virus (PCV) was studied by comparing the amplification in vivo of RNAs with GAC, GΔC, or CCA anticodons in the tRNA-like structure (TLS) present at the 3′ end of each viral RNA. The PCV RNA1 TLS of isolate PCV2 possesses a GAC anticodon and is capable of highly efficient valylation, whereas the RNA2 TLS has a GΔC anticodon that does not support valylation. The presence in RNA1 of GΔC or CCA anticodons that conferred nonvalylatability resulted in about 2- to 4-fold and a 14- to 24-fold reduction, respectively, in RNA accumulations in tobacco BY-2 protoplasts inoculated with the RNA1 variants together with wild-type RNA2(GΔC). No differences in RNA levels were observed among protoplasts inoculated with the three variant RNA2s in the presence of wild-type RNA1(GAC). All combinations of valylatable and nonvalylatable RNAs 1 and 2 were similarly infectious in Nicotiana benthamiana plants, and viral RNAs accumulated to similar levels; all input TLS sequences were present unchanged in apical leaves. In direct competition experiments in N. benthamiana plants, however, both RNA1 and RNA2 with GAC valylatable anticodons outcompeted the nonvalylatable variants. We conclude that valylation provides a small but significant replicational advantage to both PCV RNAs. Sequence analysis of the TLS from RNA2 of a second PCV isolate, PO2A, revealed the presence of an intact GAC valine anticodon, suggesting that the differential valylation of the genomic RNAs of isolate PCV2 is not a general characteristic of PCV.

scholarly journals Timing of Development of Measles-Specific Immunoglobulin M and G after Primary Measles Vaccination

1999 ◽  
Vol 6 (2) ◽  
pp. 178-180 ◽  
Author(s):  
Rita F. Helfand ◽  
Senait Kebede ◽  
Howard E. Gary ◽  
Hagos Beyene ◽  
William J. Bellini
Keyword(s):  
Positive Result ◽  
Measles Virus ◽  
Primary Vaccination ◽  
Immunoglobulin M ◽  
Measles Vaccine ◽  
Wild Type ◽  
Specific Antibodies ◽  
Specific Immunoglobulin ◽  
Measles Vaccination ◽  
Antibody Capture

ABSTRACT A standard method for diagnosing measles is to detect measles-specific immunoglobulin M (IgM) in the serum of infected persons. Interpreting a positive IgM result from a person with suspected measles can be difficult if the person has recently received a measles vaccine. We have previously demonstrated that measles-specific IgM may persist for at least 8 weeks after primary vaccination, but it is unknown how quickly IgM appears. This study determined the timing of the rise of measles-specific IgM and IgG after primary measles vaccination with Schwartz vaccine. Two hundred eighty 9-month-old children from Ethiopia presenting for routine measles vaccination were enrolled. Sera were collected before and either 1, 2, 3, or 4 weeks after vaccination and tested for measles-specific antibodies by an IgM capture enzyme immunoassay (EIA) and by an indirect IgG EIA. A total of 209 of the 224 children who returned for the second visit had prevaccination sera that were both IgM and IgG negative. The postvaccination IgM positivity rates for these 209 children were 2% at 1 week, 61% at 2 weeks, 79% at 3 weeks, and 60% at 4 weeks. The postvaccination IgG positivity rates were 0% at 1 week, 14% at 2 weeks, 81% at 3 weeks, and 85% at 4 weeks. We conclude that an IgM-positive result obtained by this antibody capture EIA is difficult to interpret if serum is collected between 8 days and 8 weeks after vaccination; in this situation, the diagnosis of measles should be based on an epidemiologic linkage to a confirmed case or on the detection of wild-type measles virus.

Mutants of Polysphondylium pallidum showing delayed modifications of glycoproteins are altered in a regulatory signal for development

1987 ◽  
Vol 87 (1) ◽  
pp. 121-132
Author(s):  
K. Toda ◽  
D. Francis ◽  
G. Gerisch
Keyword(s):  
Monoclonal Antibody ◽  
Early Stage ◽  
Developmental Regulation ◽  
Cell Aggregation ◽  
Carbohydrate Structure ◽  
Wild Type ◽  
Polysphondylium Pallidum ◽  
Carbohydrate Epitope ◽  
Regulatory Signal ◽  
Cell Surface Glycoproteins

Binding of a monoclonal antibody, mAb293, to cell-surface glycoproteins of Polysphondylium pallidum is known to be blocked by L-fucose, and Fab of this antibody has been shown to inhibit intercellular adhesion of aggregation-competent cells. Mutants with delayed expression of the carbohydrate epitope, ep293, recognized by the antibody, have been shown to be retarded and altered in cell aggregation. The present study shows that ep293 is a modification of carbohydrate structure that is subject to regulation not only in mutant but also in wild-type cells; ep293 is expressed at an early stage of exponential growth in wild-type and only after 12 h of starvation in mutant PN6002. Proteins are already glycosylated before the epitope is expressed. The developmental regulation of pallidin, a lectin known to be an unglycosylated protein, was investigated in parallel with ep293 using a monoclonal antibody. Pallidin was expressed at about the same time as the carbohydrate epitope in cells of the wild-type as well as the mutant. These results indicate a regulatory signal to which various events are coupled. Induction of ep293 and expression of pallidin are two of these events, and mutants such as PN6002 are altered in the timing of the signal.

Developmental regulation of a novel repetitive protein of Trypanosoma brucei

1987 ◽  
Vol 7 (8) ◽  
pp. 2838-2844
Author(s):  
M R Mowatt ◽  
C E Clayton
Keyword(s):  
Trypanosoma Brucei ◽  
Tandem Repeats ◽  
Signal Sequence ◽  
Developmental Regulation ◽  
Developmentally Regulated ◽  
Hydrophobic Domain ◽  
Reading Frame ◽  
Amino Terminal ◽  
Membrane Bound

Trypanosoma brucei undergoes many morphological and biochemical changes during transformation from the bloodstream trypomastigote to the insect procyclic trypomastigote form. We cloned and determined the complete nucleotide sequence of a developmentally regulated cDNA. The corresponding mRNA was abundant in in vitro-cultivated procyclics but absent in bloodstream forms. The trypanosome genome contains eight genes homologous to this cDNA, arranged as four unlinked pairs of tandem repeats. The longest open reading frame of the cDNA predicts a protein of 15 kilodaltons, the central portion of which consists of 29 tandem glutamate-proline dipeptides. The repetitive region is preceded by an amino-terminal signal sequence and followed by a hydrophobic domain that could serve as a membrane anchor; the mRNA was found on membrane-bound polyribosomes. These results suggest that the protein is membrane associated.

Pulmonary vascular response to normoxia and KCa channel activity is developmentally regulated

2001 ◽  
Vol 280 (6) ◽  
pp. L1250-L1257 ◽  
Author(s):  
Michael T. Rhodes ◽  
Valerie A. Porter ◽  
Connie B. Saqueton ◽  
Jean M. Herron ◽  
Ernesto R. Resnik ◽  
...  
Keyword(s):  
Developmental Regulation ◽  
Pulmonary Arteries ◽  
Critical Time ◽  
Pulmonary Vasculature ◽  
Mrna Levels ◽  
Channel Activity ◽  
Developmentally Regulated ◽  
Channel Expression ◽  
Acute Increase ◽  
Pulmonary Artery Smooth Muscle

To address developmental regulation of pulmonary vascular O2 sensing, we tested the hypotheses that 1) fetal but not adult pulmonary artery smooth muscle cells (PASMCs) can directly sense an acute increase in O2, 2) Ca2+-sensitive K+(KCa) channel activity decreases with maturation, and 3) PASMC KCa channel expression decreases with maturation. We used fluorescence microscopy to confirm that fetal but not adult PASMCs are able to sense an acute increase in O2tension. Acute normoxia induced a 22 ± 2% decrease in cytosolic Ca2+ concentration ([Ca2+]i) in fetal PASMCs and no change in [Ca2+]i in adult PASMCs ( P < 0.01). The effects of K+channel antagonists were studied on fetal and adult PASMC [Ca2+]i. Iberiotoxin (10−9 M) caused PASMC [Ca2+]i to increase by 694 ± 22% in the fetus and caused no change in adult PASMCs. KCa channel expression and mRNA levels in distal pulmonary arteries from fetal and adult sheep were examined. Both KCachannel protein and mRNA expression in the distal pulmonary vasculature decreased with maturation. We conclude that maturation-dependent changes in PASMC O2 sensing render the fetal PASMCs uniquely sensitive to an acute increase in O2 tension at a biologically critical time point.

scholarly journals Generation of Antibody Responses to Pneumococcal Capsular Polysaccharides Is Independent of CD1 Expression in Mice

2009 ◽  
Vol 77 (5) ◽  
pp. 1976-1980 ◽  
Author(s):  
Leen Moens ◽  
Axel Jeurissen ◽  
Stefan Nierkens ◽  
Louis Boon ◽  
Luc Van Kaer ◽  
...  
Keyword(s):  
Antibody Response ◽  
The Elderly ◽  
Immunoglobulin M ◽  
Antibody Responses ◽  
Capsular Polysaccharides ◽  
Wild Type ◽  
Igg Antibody ◽  
Antibody Treatment ◽  
Serious Infection ◽  
Protection Against Infection

ABSTRACT Streptococcus pneumoniae is a bacterial microorganism that frequently causes serious infection, particularly in children and the elderly. Protection against infection with S. pneumoniae is based mainly on the generation of antibodies to the pneumococcal capsular polysaccharides (caps-PS), but the mechanisms responsible for the generation of anticapsular antibodies remain incompletely understood. The aim of the present study was to evaluate the role of CD1-restricted T cells in the antibody response to caps-PS. When immunized with Pneumo23, wild-type mice and CD1 knockout mice on BALB/c and C57BL/6 backgrounds generated immunoglobulin M (IgM) and IgG antibody responses to soluble caps-PS that were comparable. Similar results were obtained after immunization with heat-inactivated S. pneumoniae. The IgM and IgG antibody response of wild-type mice to Pneumo23 was not affected by an antagonizing monoclonal anti-CD1 antibody treatment. In summary, our data provide evidence that the antibody response to caps-PS is generated independently of CD1 expression.

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