Post-transcriptional regulation of the Bacillus subtilis pst operon encoding a phosphate-specific ABC transporter

Microbiology ◽  
2004 ◽  
Vol 150 (8) ◽  
pp. 2619-2628 ◽  
Author(s):  
Nicholas E. E. Allenby ◽  
Nicola O'Connor ◽  
Zoltán Prágai ◽  
Noel M. Carter ◽  
Marcus Miethke ◽  
...  

During phosphate starvation, Bacillus subtilis regulates genes in the PhoP regulon to reduce the cell's requirement for this essential substrate and to facilitate the recovery of inorganic phosphate from organic sources such as teichoic and nucleic acids. Among the proteins that are highly induced under these conditions is PstS, the phosphate-binding lipoprotein component of a high-affinity ABC-type phosphate transporter. PstS is encoded by the first gene in the pst operon, the other four members of which encode the integral membrane and cytoplasmic components of the transporter. The transcription of the pst operon was analysed using a combination of methods, including transcriptional reporter gene technology, Northern blotting and DNA arrays. It is shown that the primary transcript of the pst operon is processed differentially to maintain higher concentrations of PstS relative to other components of the transporter. The comparative studies have revealed limitations in the use of reporter gene technology for analysing the transcription of operons in which the messenger RNA transcript is differentially processed.

Author(s):  
Iván Peñuelas ◽  
Shahriar S. Yaghoubi ◽  
Felipe Prósper ◽  
Sanjiv Sam Gambhir

Blood ◽  
2000 ◽  
Vol 95 (9) ◽  
pp. 2733-2741 ◽  
Author(s):  
David Peters ◽  
Masahiro Tsuchida ◽  
Eric R. Manthei ◽  
Tausif Alam ◽  
Clifford S. Cho ◽  
...  

The activation of blood cells, including T cells, triggers intracellular signals that control the expression of critical molecules, including cytokines and cytokine receptors. We show that T-cell receptor (TCR) ligation increases the cellular level of the protein linker for activation of T cells (LAT), a molecule critical for T-cell development and function. T-cell activation increased LAT messenger RNA, as determined by reverse transcription–polymerase chain reaction and by Northern blotting. The TCR-induced increase in LAT expression involved the activation of the serine/threonine kinases PKC and MEK, because inhibitors of these kinases blocked the increase in LAT. Accordingly, the PKC activator phorbol myristate acetate up-regulated LAT expression. Strikingly, the calcineurin inhibitors cyclosporin A (CsA) and FK506 strongly potentiated TCR-induced LAT expression, suggesting that the activation of calcineurin following TCR ligation negatively regulates LAT expression. Accordingly, Ca++ ionophores, which can activate calcineurin by increasing intracellular Ca++, blocked the TCR-induced increase in cellular LAT. CsA and FK506 blocked the Ca++ionophores' inhibitory effect on LAT expression. Notably, CsA and FK506 preferentially up-regulated TCR-induced LAT expression; under the same conditions, these compounds did not increase the expression of 14 other molecules that previously had been implicated in T-cell activation. These data show that TCR-induced LAT expression involves the activation of the PKC-Erk pathway and is negatively regulated by the activation of calcineurin. Furthermore, the potentiation of TCR-induced LAT expression by CsA and FK506 suggests that the action of these agents involves up-regulating the cellular level of critical signaling molecules. These findings may have important therapeutic implications.


Author(s):  
Xiang Yu ◽  
Bishwas Sharma ◽  
Brian D Gregory

Abstract Ribonucleotides within the various RNA molecules in eukaryotes are marked with more than 160 distinct covalent chemical modifications. These modifications include those that occur internally in messenger RNA (mRNA) molecules such as N6-methyladenosine (m6A) and 5-methylcytosine (m5C), as well as those that occur at the ends of the modified RNAs like the non-canonical 5′ end nicotinamide adenine dinucleotide (NAD+) cap modification of specific mRNAs. Recent findings have revealed that covalent RNA modifications can impact the secondary structure, translatability, functionality, stability and degradation of the RNA molecules in which they are included. Many of these covalent RNA additions have also been found to be dynamically added and removed through writer and eraser complexes, respectively, providing a new layer of epitranscriptome-mediated post-transcriptional regulation that regulates RNA quality and quantity in eukaryotic transcriptomes. Thus, it is not surprising that the regulation of RNA fate mediated by these epitranscriptomic marks has been demonstrated to have widespread effects on plant development and the responses of these organisms to abiotic and biotic stresses. In this review, we highlight recent progress focused on the study of the dynamic nature of these epitranscriptome marks and their roles in post-transcriptional regulation during plant development and response to environmental cues, with an emphasis on the mRNA modifications of non-canonical 5′ end NAD+ capping, m6A and several other internal RNA modifications.


1969 ◽  
Vol 113 (1) ◽  
pp. 29-37 ◽  
Author(s):  
Janet M. Sterlini ◽  
J. Mandelstam

1. Experiments to determine the point of commitment to sporulation were carried out by restoring nutrients at different times to suspensions of sporulating Bacillus subtilis. 2. No single point of commitment to the process as a whole was found. Instead, the cells became committed in turn to the following successive events connected with sporulation: formation of alkaline phosphatase, development of refractility, synthesis of dipicolinic acid and development of heat-resistance. 3. Each point of commitment was followed within about 30min. by a period in which the event concerned ceased to be inhibited by actinomycin D. 4. The implication of these results is that each point of commitment is probably due to the formation of a species of long-lived messenger RNA and that, in any case, sporulation is regulated at the level of both transcription and translation. 5. It is also shown that sporulation and growth are perhaps not mutually exclusive functions and that histidase, an enzyme typical of the vegetative state, can be induced in sporulating suspensions.


2001 ◽  
Vol 183 (24) ◽  
pp. 7329-7340 ◽  
Author(s):  
Robert Caldwell ◽  
Ron Sapolsky ◽  
Walter Weyler ◽  
Randal R. Maile ◽  
Stuart C. Causey ◽  
...  

ABSTRACT The availability of the complete sequence of the Bacillus subtilis chromosome (F. Kunst et al., Nature 390:249–256, 1997) makes possible the construction of genome-wide DNA arrays and the study of this organism on a global scale. Because we have a long-standing interest in the effects of scoC on late-stage developmental phenomena as they relate toaprE expression, we studied the genome-wide effects of ascoC null mutant with the goal of furthering the understanding of the role of scoC in growth and developmental processes. In the present work we compared the expression patterns of isogenic B. subtilis strains, one of which carries a null mutation in the scoC locus (scoC4). The results obtained indicate thatscoC regulates, either directly or indirectly, the expression of at least 560 genes in the B. subtilisgenome. ScoC appeared to repress as well as activate gene expression. Changes in expression were observed in genes encoding transport and binding proteins, those involved in amino acid, carbohydrate, and nucleotide and/or nucleoside metabolism, and those associated with motility, sporulation, and adaptation to atypical conditions. Changes in gene expression were also observed for transcriptional regulators, along with sigma factors, regulatory phosphatases and kinases, and members of sensor regulator systems. In this report, we discuss some of the phenotypes associated with the scoCmutant in light of the transcriptome changes observed.


2010 ◽  
Vol 298 (5) ◽  
pp. R1366-R1374 ◽  
Author(s):  
O. Khorram ◽  
G. Han ◽  
R. Bagherpour ◽  
T. R. Magee ◽  
M. Desai ◽  
...  

The aim of this study was to test the hypothesis that maternal undernutrition (MUN) alters offspring vascular expression of micro-RNAs (miRNAs), which, in turn, could regulate the expression of a host of genes involved with angiogenesis and extracellular matrix remodeling. The expression of miRNA and mRNA in the same aortic specimens in 1-day-old (P1) and 12-mo-old offspring aortas of dams, which had 50% food restriction from gestation day 10 to term, was determined by specific rat miRNA and DNA arrays. MUN significantly downregulated the expression of miRNAs 29c, 183, and 422b in the P1 group and 200a, 129, 215, and 200b in the 12-mo group, and upregulated the expression of miRNA 189 in the P1 group and 337 in the 12-mo group. The predicted target genes of the miRNAs altered in the two age groups fell into the categories of: 1) structural genes, such as collagen, elastin, and enzymes involved in ECM remodeling; and 2) angiogenic factors. MUN primarily altered the expression of mRNAs in the functional category of cell cycle/mitosis in the P1 group and anatomic structure and apoptosis in the 12-mo age group. Several of the predicted target genes of miRNAs altered in response to MUN were identified by the DNA array including integrin-β1 in the P1 aortas and stearoyl-CoA desaturase-1 in the 12-mo age groups. These results are consistent with the hypothesis that MUN modulation of offspring gene expression may be mediated in part by a miRNA mechanism.


1996 ◽  
Vol 133 (3) ◽  
pp. 667-681 ◽  
Author(s):  
Y Kanai ◽  
M Kanai-Azuma ◽  
T Noce ◽  
T C Saido ◽  
T Shiroishi ◽  
...  

The different mRNA isoforms of the mouse Sox17 gene were isolated from adult mouse testis cDNAs. One form (referred to as form Sox17) encodes an Sry-related protein of 419 amino acids containing a single high mobility group box near the NH2-terminus, while the other form (referred to as form t-Sox17) shows a unique mRNA isoform of the Sox17 gene with a partial deletion of the HMG box region. Analysis of genomic DNA revealed that these two isoforms were produced at least by alternative splicing of the exon corresponding to the 5' untranslated region and NH2-terminal 102 amino acids. RNA analyses in the testis revealed that form Sox17 began at the pachytene spermatocyte stage and was highly accumulated in round spermatids. Protein analyses revealed that t-Sox17 isoforms, as well as Sox17 isoforms, were translated into the protein products in the testis, although the amount of t-Sox17 products is lower in comparison to the high accumulation of t-Sox17 mRNA. By the electrophoretic mobility-shift assay and the random selection assay using recombinant Sox17 and t-Sox17 proteins, Sox17 protein is a DNA-binding protein with a similar sequence specificity to Sry and the other members of Sox family proteins, while t-Sox17 shows no apparent DNA-binding activity. Moreover, by a cotransfection experiment using a luciferase reporter gene, Sox17 could stimulate transcription through its binding site, but t-Sox17 had little effect on reporter gene expression. Thus, these findings suggest that Sox17 may function as a transcriptional activator in the premeiotic germ cells, and that a splicing switch into t-Sox17 may lead to the loss of its function in the postmeiotic germ cells.


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