A repressor controls the timing and spatial localisation of stalk cell-specific gene expression in Dictyostelium

Development ◽  
1993 ◽  
Vol 118 (4) ◽  
pp. 1041-1048 ◽  
Author(s):  
A.J. Harwood ◽  
A. Early ◽  
J.G. Williams
Keyword(s):  
Gene Expression ◽  
Transcriptional Repression ◽  
Consensus Sequence ◽  
Matrix Proteins ◽  
Stalk Cell ◽  
Specific Gene ◽  
Gene Mutant ◽  
Dependent Protein ◽  
Apical Papilla ◽  
Repressor Element

The ecmA and ecmB genes of Dictyostelium encode related extracellular matrix proteins and both are induced by DIF, the stalk cell-specific morphogen. The ecmA gene is expressed throughout the prestalk region of the migrating slug but only later, at culmination, do the prestalk cells express the ecmB gene. Expression of the ecmB gene is induced at the entrance to the stalk tube and we have identified two, apparently redundant, promoter elements that control this process. They act as repressors, preventing transcription in the tip of the migrating slug and the apical papilla of the culminant. They have a semi-palindromic consensus sequence TTGnCAA, where n is in one case 2 and in the other 4 bp. Either element alone is able to repress ecmB promoter activity in prestalk cells. Introduction of a single repressor element into the promoter of the ecmA gene changes its expression pattern to resemble that of the ecmB gene. Mutant elements, where n is altered, cause repression during the slug stage but allow premature ecmB expression during culmination; suggesting that the effective strength of the inductive signal may increase during culmination. Inhibition of cAMP-dependent protein kinase (PKA) in prestalk cells blocks both stalk cell maturation and ecmB gene expression. We show that the block to gene expression correlates precisely with the presence of a functional repressor element and this is consistent with the notion that expression of the ecmB gene is controlled by a PKA-dependent release from transcriptional repression.

scholarly journals Cyclic AMP-dependent protein kinase inhibits the activity of myogenic helix-loop-helix proteins.

1992 ◽  
Vol 12 (10) ◽  
pp. 4478-4485 ◽  
Author(s):  
L Li ◽  
R Heller-Harrison ◽  
M Czech ◽  
E N Olson
Keyword(s):  
Protein Kinase ◽  
Cyclic Amp ◽  
Transcriptional Activation ◽  
Consensus Sequence ◽  
Signal Transduction Pathway ◽  
Specific Gene ◽  
Dependent Protein Kinase ◽  
Dependent Protein

Differentiation of skeletal muscle cells is inhibited by the cyclic AMP (cAMP) signal transduction pathway. Here we report that the catalytic subunit of cAMP-dependent protein kinase (PKA) can substitute for cAMP and suppress muscle-specific transcription by silencing the activity of the MyoD family of regulatory factors, which includes MyoD, myogenin, myf5, and MRF4. Repression by the PKA catalytic (C) subunit is directed at the consensus sequence CANNTG, the target for DNA binding and transcriptional activation by these myogenic regulators. Phosphopeptide mapping of myogenin in vitro and in vivo revealed two PKA phosphorylation sites, both within the basic region. However, repression of myogenin function by PKA does not require direct phosphorylation of these sites but instead involves an indirect mechanism with one or more intermediate steps. Regulation of the transcriptional activity of the MyoD family by modulation of the cAMP signaling pathway may account for the inhibitory effects of certain peptide growth factors on muscle-specific gene expression and may also determine the responsiveness of different cell types to myogenic conversion by these myogenic regulators.

Cyclic AMP-dependent protein kinase inhibits the activity of myogenic helix-loop-helix proteins

1992 ◽  
Vol 12 (10) ◽  
pp. 4478-4485
Author(s):  
L Li ◽  
R Heller-Harrison ◽  
M Czech ◽  
E N Olson
Keyword(s):  
Protein Kinase ◽  
Cyclic Amp ◽  
Transcriptional Activation ◽  
Consensus Sequence ◽  
Signal Transduction Pathway ◽  
Specific Gene ◽  
Dependent Protein Kinase ◽  
Dependent Protein

Differentiation of skeletal muscle cells is inhibited by the cyclic AMP (cAMP) signal transduction pathway. Here we report that the catalytic subunit of cAMP-dependent protein kinase (PKA) can substitute for cAMP and suppress muscle-specific transcription by silencing the activity of the MyoD family of regulatory factors, which includes MyoD, myogenin, myf5, and MRF4. Repression by the PKA catalytic (C) subunit is directed at the consensus sequence CANNTG, the target for DNA binding and transcriptional activation by these myogenic regulators. Phosphopeptide mapping of myogenin in vitro and in vivo revealed two PKA phosphorylation sites, both within the basic region. However, repression of myogenin function by PKA does not require direct phosphorylation of these sites but instead involves an indirect mechanism with one or more intermediate steps. Regulation of the transcriptional activity of the MyoD family by modulation of the cAMP signaling pathway may account for the inhibitory effects of certain peptide growth factors on muscle-specific gene expression and may also determine the responsiveness of different cell types to myogenic conversion by these myogenic regulators.

scholarly journals The Repressor Element 1-Silencing Transcription Factor Regulates Heart-Specific Gene Expression Using Multiple Chromatin-Modifying Complexes

2007 ◽  
Vol 27 (11) ◽  
pp. 4082-4092 ◽  
Author(s):  
Andrew J. Bingham ◽  
Lezanne Ooi ◽  
Lukasz Kozera ◽  
Edward White ◽  
Ian C. Wood
Keyword(s):  
Gene Expression ◽  
Transcription Factor ◽  
Cardiac Hypertrophy ◽  
Gene Expression Profile ◽  
Expression Profile ◽  
Molecular Mechanisms ◽  
Ventricular Myocytes ◽  
Specific Gene ◽  
Histone H4 Acetylation ◽  
Repressor Element

ABSTRACT Cardiac hypertrophy is associated with a dramatic change in the gene expression profile of cardiac myocytes. Many genes important during development of the fetal heart but repressed in the adult tissue are reexpressed, resulting in gross physiological changes that lead to arrhythmias, cardiac failure, and sudden death. One transcription factor thought to be important in repressing the expression of fetal genes in the adult heart is the transcriptional repressor REST (repressor element 1-silencing transcription factor). Although REST has been shown to repress several fetal cardiac genes and inhibition of REST function is sufficient to induce cardiac hypertrophy, the molecular mechanisms employed in this repression are not known. Here we show that continued REST expression prevents increases in the levels of the BNP (Nppb) and ANP (Nppa) genes, encoding brain and atrial natriuretic peptides, in adult rat ventricular myocytes in response to endothelin-1 and that inhibition of REST results in increased expression of these genes in H9c2 cells. Increased expression of Nppb and Nppa correlates with increased histone H4 acetylation and histone H3 lysine 4 methylation of promoter-proximal regions of these genes. Furthermore, using deletions of individual REST repression domains, we show that the combined activities of two domains of REST are required to efficiently repress transcription of the Nppb gene; however, a single repression domain is sufficient to repress the Nppa gene. These data provide some of the first insights into the molecular mechanism that may be important for the changes in gene expression profile seen in cardiac hypertrophy.

Genomic editing of intronic enhancers unveils their role in fine-tuning tissue-specific gene expression in Arabidopsis thaliana

2021 ◽  
Author(s):  
Fanli Meng ◽  
Hainan Zhao ◽  
Bo Zhu ◽  
Tao Zhang ◽  
Mingyu Yang ◽  
...  
Keyword(s):  
Gene Expression ◽  
Arabidopsis Thaliana ◽  
Transcriptional Repression ◽  
Regulation Of Gene Expression ◽  
Fine Tuning ◽  
Specific Gene ◽  
Open Chromatin ◽  
Floral Tissue ◽  
Deletion Lines ◽  
A Genome

Abstract Enhancers located in introns are abundant and play a major role in the regulation of gene expression in mammalian species. By contrast, the functions of intronic enhancers in plants have largely been unexplored and only a handful of plant intronic enhancers have been reported. We performed a genome-wide prediction of intronic enhancers in Arabidopsis thaliana using open chromatin signatures based on DNase I sequencing. We identified 941 candidate intronic enhancers associated with 806 genes in seedling tissue and 1,271 intronic enhancers associated with 1,069 genes in floral tissue. We validated the function of 15 of 21 (71%) of the predicted intronic enhancers in transgenic assays using a reporter gene. We also created deletion lines of three intronic enhancers associated with two different genes using CRISPR/Cas. Deletion of these enhancers, which span key transcription factor binding sites, did not abolish gene expression but caused varying levels of transcriptional repression of their cognate genes. Remarkably, the transcriptional repression of the deletion lines occurred at specific developmental stages and resulted in distinct phenotypic effects on plant morphology and development. Clearly, these three intronic enhancers are important in fine-tuning tissue- and development-specific expression of their cognate genes.

Identification and analysis of a gene that is essential for morphogenesis and prespore cell differentiation in Dictyostelium

Development ◽  
1998 ◽  
Vol 125 (14) ◽  
pp. 2565-2576 ◽  
Author(s):  
H. Yasukawa ◽  
S. Mohanty ◽  
R.A. Firtel
Keyword(s):  
Gene Expression ◽  
Cell Differentiation ◽  
Cell Fate ◽  
Stalk Cell ◽  
Specific Gene ◽  
Wild Type ◽  
Cell Type ◽  
Primary Defect ◽  
Experimental Conditions ◽  
Prespore Cell

We have identified a gene (PslA) that is expressed throughout Dictyostelium development and encodes a novel protein that is required for proper aggregation and subsequent cell-type differentiation and morphogenesis. pslA null (pslA-) cells produce large aggregation streams under conditions in which wild-type cells form discrete aggregates. Tips form along the stream, elongate to produce a finger, and eventually form a terminal structure that lacks a true sorus (spore head). More than half of the cells remain as a mass at the base of the developing fingers. The primary defect in the pslA- strain is the inability to induce prespore cell differentiation. Analyses of gene expression show a complete lack of prespore-specific gene expression and no mature spores are produced. In chimeras with wild-type cells, pslA- cells form the prestalk domain and normal, properly proportioned fruiting bodies can be produced. This indicates that pslA- cells are able to interact with wild-type cells and regulate patterning, even though pslA- cells are unable to express prespore cell-type-specific genes, do not participate in prespore cell differentiation and do not produce pslA- spores in the chimeras. While pslA- cells produce mature, vacuolated stalk cells during multicellular development, pslA- cells are unable to do so in vitro in response to exogenous DIF (a morphogen required for prestalk and stalk cell differentiation). These results indicate that pslA- cells exhibit a defect in the prestalk/stalk cell pathways under these experimental conditions. Our results suggest that PslA's primary function is to regulate prespore cell determination very early in the prespore pathway via a cell-autonomous mechanism, possibly at the time of the initial prestalk/prespore cell-fate decision. Indirect immunofluorescence of myc-tagged PslA localizes the protein to the nucleus, suggesting that PslA may function to control the prespore pathway at the level of transcription.

scholarly journals cGMP-dependent protein kinase and the regulation of vascular smooth muscle cell gene expression: possible involvement of Elk-1 sumoylation

2010 ◽  
Vol 299 (5) ◽  
pp. H1660-H1670 ◽  
Author(s):  
ChungSik Choi ◽  
Hassan Sellak ◽  
Felricia M. Brown ◽  
Thomas M. Lincoln
Keyword(s):  
Gene Expression ◽  
Smooth Muscle ◽  
Protein Kinase ◽  
Smooth Muscle Cell ◽  
Muscle Cell ◽  
Specific Gene ◽  
Dependent Protein Kinase ◽  
Cgmp Dependent Protein Kinase ◽  
Vascular Smcs ◽  
Dependent Protein

Although the regulation of smooth muscle cell (SMC) gene expression by cGMP-dependent protein kinase (PKG) is now recognized, the mechanisms underlying these effects are not fully understood. In this study, we report that PKG-I stimulates myocardin/serum response factor (SRF)-dependent gene expression in vascular SMCs. The expression of PKG in PKG-deficient cells enhanced myocardin-induced SM22 promoter activity in a concentration-dependent fashion. However, neither SRF nor myocardin expression was affected. To investigate alternative mechanisms, we examined whether PKG affects the phosphorylation of E26-like protein-1 (Elk-1), a SRF/myocardin transcription antagonist. The activation of PKG caused an increase in a higher molecular mass form of phospho-Elk-1 that was determined to be small ubiquitin-related modifier (sumo)ylated Elk-1. PKG increased Elk-1 sumoylation twofold compared with the PKG-deficient cells, and Elk-1 sumoylation was reduced using dominant-negative sumo-conjugating enzyme, DN-Ubc9, confirming PKG-dependent sumoylation of phospho-Elk-1 in vascular SMCs. In addition, PKG stimulated Elk-1 sumoylation in COS-7 cells overexpressing Elk-1, sumo-1, and PKG-I. The increased expression of PKG in vascular SMCs inhibited Elk-1 binding to SMC-specific promoters, SM22 and smooth muscle myosin heavy chain, as measured by EMSA and chromatin immunoprecipitation assay, and PKG suppressed the Elk-1 inhibition of SM22 reporter gene expression. Taken together, these data suggest that PKG-I decreases Elk-1 activity by sumo modification of Elk-1, thereby increasing myocardin-SRF activity on SMC-specific gene expression.

Characterisation of a DNA sequence element that directs Dictyostelium stalk cell-specific gene expression

2000 ◽  
Vol 66 (4-5) ◽  
pp. 189-196 ◽  
Author(s):  
A. Ceccarelli ◽  
N. Zhukovskaya ◽  
T. Kawata ◽  
S. Bozzaro ◽  
J. Williams
Keyword(s):  
Gene Expression ◽  
Dna Sequence ◽  
Stalk Cell ◽  
Specific Gene ◽  
Sequence Element ◽  
Specific Gene Expression

Prospective isolation and global gene expression analysis of the erythrocyte colony-forming unit (CFU-E)

Blood ◽  
2005 ◽  
Vol 105 (5) ◽  
pp. 1937-1945 ◽  
Author(s):  
Grzegorz Terszowski ◽  
Claudia Waskow ◽  
Peter Conradt ◽  
Dido Lenze ◽  
Jessica Koenigsmann ◽  
...  
Keyword(s):  
Gene Expression ◽  
Consensus Sequence ◽  
Gene Expression Pattern ◽  
Global Gene Expression ◽  
Specific Gene ◽  
Erythroid Progenitor ◽  
Colony Forming Unit ◽  
Global Gene Expression Analysis ◽  
Prospective Isolation

Abstract The erythrocyte colony-forming unit (CFU-E) is a rare bone marrow (BM) progenitor that generates erythrocyte colonies in 48 hours. The existence of CFU-Es is based on these colonies, but CFU-Es have not been purified prospectively by phenotype. We have separated the “nonstem,” “nonlymphoid” compartment (lineage marker [lin]–c-Kit+Sca-1–IL-7Rα–) into interleukin 3 receptor α negative (IL-3Rα–) and IL-3Rα+ subsets. Within IL-3Rα– but not IL-3Rα+ cells we have identified TER119–CD41–CD71+ erythrocyte-committed progenitors (EPs). EPs generate CFU-E colonies at about 70% efficiency and generate reticulocytes in vivo. Depletion of EPs from BM strongly reduces CFU-E frequencies. EPs lack potential for erythrocyte burst-forming unit, megakaryocyte, granulocyte (G), and monocyte (M) colonies, and for spleen colony-forming units. Chronically suppressed erythropoiesis in interferon consensus sequence-binding protein (ICSBP)–deficient BM is associated with reduced frequencies of both the EP population and CFU-E colonies. During phenylhydrazine-induced acute anemia, numbers of both the EP population and CFU-E colonies increase. Collectively, EPs (lin–c-Kit+Sca-1–IL-7Rα–IL-3Rα–CD41–CD71+) account for most, if not all, CFU-E activity in BM. As a first molecular characterization, we have compared global gene expression in EPs and nonerythroid GM progenitors. These analyses define an erythroid progenitor-specific gene expression pattern. The prospective isolation of EPs is an important step to analyze physiologic and pathologic erythropoiesis.

scholarly journals A Cysteine-rich LIM-only Protein Mediates Regulation of Smooth Muscle-specific Gene Expression by cGMP-dependent Protein Kinase

2007 ◽  
Vol 282 (46) ◽  
pp. 33367-33380 ◽  
Author(s):  
Tong Zhang ◽  
Shunhui Zhuang ◽  
Darren E. Casteel ◽  
David J. Looney ◽  
Gerry R. Boss ◽  
...  
Keyword(s):  
Gene Expression ◽  
Smooth Muscle ◽  
Specific Gene ◽  
Dependent Protein Kinase ◽  
Small Interference Rna ◽  
Specific Gene Expression ◽  
Cgmp Dependent Protein Kinase ◽  
Dependent Protein ◽  
Actin Promoter ◽  
Stimulation Of

Vascular smooth muscle cells (VSMCs) undergo phenotypic modulation, changing from a differentiated, contractile to a de-differentiated, synthetic phenotype; the change is associated with decreased expression of smooth muscle (SM)-specific genes and loss of cGMP-dependent protein kinase (PKG), but transfection of PKG into de-differentiated VSMCs restores SM-specific gene expression. We show that small interference RNA-mediated down-regulation or pharmacologic inhibition of PKG reduced SM-specific gene expression in differentiated VSMCs and provide a mechanism for cGMP/PKG regulation of SM-specific genes involving the cysteine-rich LIM-only protein CRP4. PKG associated with CRP4 and phosphorylated the protein in intact cells. CRP4 had no intrinsic transcriptional activity, but exhibited adaptor function, because it acted synergistically with serum response factor (SRF) and GATA6 to activate the SM-α-actin promoter. cGMP stimulation of the promoter required PKG and CRP4 co-expression with SRF and GATA6. A phosphorylation-deficient mutant CRP4 and a CRP4 deletion mutant deficient in PKG binding did not support cGMP/PKG stimulation of the SM-α-actin promoter. In the presence of wild-type but not mutant CRP4, cGMP/PKG enhanced SRF binding to a probe encoding the distal SM-α-actin promoter CArG (CC(AT)6GG) element. CRP4 and SRF associated with CArG elements of endogenous SM-specific genes in intact chromatin. Small interference RNA-mediated down-regulation of CRP4 prevented the positive effects of cGMP/PKG on SM-specific gene expression. In the presence of CRP4, cGMP/PKG increased SRF- and GATA6-dependent expression of endogenous SM-specific genes in pluripotent 10T1/2 cells. Thus, CRP4 mediates cGMP/PKG stimulation of SM-specific gene expression, and PKG plays an important role in regulating the phenotype of VSMCs.

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