Extracellular cAMP can restore development in Dictyostelium cells lacking one, but not two subtypes of early cAMP receptors (cARs). Evidence for involvement of cAR1 in aggregative gene expression

Development ◽  
1994 ◽  
Vol 120 (7) ◽  
pp. 1997-2002
Author(s):  
R.D. Soede ◽  
R.H. Insall ◽  
P.N. Devreotes ◽  
P. Schaap
Keyword(s):  
Gene Expression ◽  
Cell Lines ◽  
Gene Disruption ◽  
Developmentally Regulated ◽  
Developmental Gene Expression ◽  
Genes Expression ◽  
Affinity Receptor ◽  
Car1 Gene ◽  
Camp Receptor ◽  
Extracellular Camp

Extracellular cAMP induces expression of several classes of developmentally regulated genes in Dictyostelium. Four highly homologous surface cAMP receptors (cARs) were identified earlier, but involvement of specific cARs in gene regulation has not been clarified. Cells lacking the chemotactic receptor, cAR1, neither aggregate nor express developmentally regulated genes. Expression of aggregative genes is in wild-type cells induced by nanomolar cAMP pulses and repressed by persistent micromolar cAMP stimuli, which induce expression of prespore and prestalk-enriched genes during the postaggregative stages of development. We show here that in cell lines carrying a cAR1 gene disruption, nanomolar pulses cannot induce aggregative gene expression. Remarkably, micromolar cAMP can induce expression of aggregative genes in car1- cells as well as expression of prespore and prestalk-enriched genes, and furthermore restores their ability to form normal slugs and fruiting bodies. These data indicate that cAR1 mediates aggregative but not postaggregative gene expression and morphogenesis, and suggest that after gene disruption, its function is partially taken over by a lower affinity receptor that is not subjected to desensitization. The absence of another early cAMP receptor, cAR3, does not affect development. However, in a car1-/car3- double mutant, cAMP stimulation cannot restore any developmental gene expression, indicating that cAR3 may have substituted for cAR1 in car1- cell lines.

Sequence-specific protein interaction with a transcriptional enhancer involved in the autoregulated expression of cAMP receptor 1 in Dictyostelium

Development ◽  
1998 ◽  
Vol 125 (18) ◽  
pp. 3689-3698
Author(s):  
X. Mu ◽  
B. Lee ◽  
J.M. Louis ◽  
A.R. Kimmel
Keyword(s):  
Gene Expression ◽  
Early Development ◽  
Specific Interaction ◽  
Early Gene ◽  
Specific Gene ◽  
Critical Element ◽  
Molecular Response ◽  
Continuous Exposure ◽  
Camp Receptor ◽  
Extracellular Camp

Major stages of Dictyostelium development are regulated by secreted, extracellular cAMP through activation of a serpentine receptor family. During early development, oscillations of extracellular cAMP mobilize cells for aggregation; later, continuous exposure to higher extracellular cAMP concentrations downregulates early gene expression and promotes cytodifferentiation and cell-specific gene expression. The cAMP receptor 1 gene CAR1 has two promoters that are differentially responsive to these extracellular cAMP stimuli. The early CAR1 promoter is induced by nM pulses of cAMP, which in turn are generated by CAR1-dependent activation of adenylyl cyclase (AC). Higher, non-fluctuating concentrations of cAMP will adapt this AC stimulus-response, repress the activated early promoter and induce the dormant late promoter. We now identify a critical element of the pulse-induced CAR1 promoter and a nuclear factor with sequence-specific interaction. Mutation of four nucleotides within the element prevents both in vitro protein binding and in vivo expression of an otherwise fully active early CAR1 promoter and multimerization of the wild-type, but not mutant, sequence will confer cAMP regulation to a quiescent heterologous promoter. These cis and trans elements, thus, constitute a part of the molecular response to the cAMP transmembrane signal cascade that regulates early development of Dictyostelium.

scholarly journals c-Maf Interacts with c-Myb To Regulate Transcription of an Early Myeloid Gene during Differentiation

1998 ◽  
Vol 18 (5) ◽  
pp. 2729-2737 ◽  
Author(s):  
Shrikanth P. Hegde ◽  
Alok Kumar ◽  
Cornelia Kurschner ◽  
Linda H. Shapiro
Keyword(s):  
Gene Expression ◽  
Cell Lines ◽  
Reporter Gene ◽  
Developmental Stages ◽  
Myeloid Cells ◽  
Myeloid Cell ◽  
Specific Gene ◽  
Developmentally Regulated ◽  
Protein Levels ◽  
Transcription Expression

ABSTRACT The MafB transcriptional activator plays a pivotal role in regulating lineage-specific gene expression during hematopoiesis by repressing Ets-1-mediated transcription of key erythroid-specific genes in myeloid cells. To determine the effects of Maf family proteins on the transactivation of myeloid-specific genes in myeloid cells, we tested the ability of c-Maf to influence Ets-1- and c-Myb-dependentCD13/APN transcription. Expression of c-Maf in human immature myeloblastic cells inhibited CD13/APN-driven reporter gene activity (85 to 95% reduction) and required the binding of both c-Myb and Ets, but not Maf, to the promoter fragment. c-Maf’s inhibition of CD13/APN expression correlates with its ability to physically associate with c-Myb. While c-Maf mRNA and protein levels remain constant during myeloid differentiation, formation of inhibitory Myb-Maf complexes was developmentally regulated, with their levels being highest in immature myeloid cell lines and markedly decreased in cell lines representing later developmental stages. This pattern matched that of CD13/APNreporter gene expression, indicating that Maf modulation of c-Myb activity may be an important mechanism for the control of gene transcription during hematopoietic cell development.

scholarly journals Extracellular cAMP is sufficient to restore developmental gene expression and morphogenesis in Dictyostelium cells lacking the aggregation adenylyl cyclase (ACA).

1993 ◽  
Vol 7 (11) ◽  
pp. 2172-2180 ◽  
Author(s):  
G S Pitt ◽  
R Brandt ◽  
K C Lin ◽  
P N Devreotes ◽  
P Schaap
Keyword(s):  
Gene Expression ◽  
Adenylyl Cyclase ◽  
Developmental Gene ◽  
Developmental Gene Expression ◽  
Extracellular Camp

scholarly journals Cell-specific transcriptional regulation and reactivation of galectin-1 gene expression are controlled by DNA methylation of the promoter region.

1996 ◽  
Vol 16 (6) ◽  
pp. 2736-2743 ◽  
Author(s):  
G Benvenuto ◽  
M L Carpentieri ◽  
P Salvatore ◽  
L Cindolo ◽  
C B Bruni ◽  
...  
Keyword(s):  
Gene Expression ◽  
Dna Methylation ◽  
Cell Lines ◽  
Promoter Region ◽  
Close Correlation ◽  
Small Region ◽  
Developmentally Regulated ◽  
Endogenous Gene ◽  
Highly Active

The galectin-1 gene is developmentally regulated gene whose activity is strongly modulated during cell differentiation and transformation. We have previously shown that galectin-1 promoter constructs are highly active when transiently transfected in cells both expressing and not expressing the endogenous gene and that the basal activity is determined by a small region encompassing the transcription start site (from positions -50 to +50). We have now investigated the role of DNA methylation in galectin-1 gene expression. Southern blot analysis with HpaII and MspI endonucleases and sodium bisulfite analysis of genomic DNA from expressing and nonexpressing cell lines and cell hybrids showed a close correlation between gene activity and demethylation of the 5' region of the galectin-1 gene. We found that the galectin-1 promoter region is fully methylated, at every CpG site on both strands, in nonexpressing differentiated rat liver (FAO) and thyroid (PC C13) cells and unmethylated in the expressing undifferentiated liver (BRL3A) and thyroid transformed (PC myc/raf) cell lines. In addition, reactivation of the silent FAO alleles in FAO-human osteosarcoma (143tk-) hybrid cells is accompanied by a complete demethylation of the promoter region. Finally, when galectin-1 chloramphenicol acetyltransferase (CAT) promoter constructs were methylated in vitro by SssI methylase at every cytosine residue of the CpG doublets and transfected into mouse fibroblasts, the transcription of the CAT reporter gene was strongly inhibited.

Identification of Differentially Expressed Genes Using cDNA-AFLP During Six Days In Vitro Tuberization of Potato

Zuriat ◽  
2015 ◽  
Vol 14 (1) ◽  
Author(s):  
Nono Carsono ◽  
Christian Bachem
Keyword(s):  
Gene Expression ◽  
Developmental Process ◽  
Expression Patterns ◽  
Induction Medium ◽  
In Vitro Tuberization ◽  
Storage Organ ◽  
Developmentally Regulated ◽  
Study Gene Expression ◽  
Differential Pattern

Tuberization in potato is a complex developmental process resulting in the differentiation of stolon into the storage organ, tuber. During tuberization, change in gene expression has been known to occur. To study gene expression during tuberization over the time, in vitro tuberization system provides a suitable tool, due to its synchronous in tuber formation. An early six days axillary bud growing on tuber induction medium is a crucial development since a large number of genes change in their expression patterns during this period. In order to identify, isolate and sequencing the genes which displaying differential pattern between tuberizing and non-tuberizing potato explants during six days in vitro tuberization, cDNA-AFLP fingerprint, method for the visualization of gene expression using cDNA as template which is amplified to generate an RNA-fingerprinting, was used in this experiment. Seventeen primer combinations were chosen based on their expression profile from cDNA-AFLP fingerprint. Forty five TDFs (transcript derived fragment), which displayed differential expressions, were obtained. Tuberizing explants had much more TDFs, which developmentally regulated, than those from non tuberizing explants. Seven TDFs were isolated, cloned and then sequenced. One TDF did not find similarity in the current databases. The nucleotide sequence of TDF F showed best similarity to invertase ezymes from the databases. The homology of six TDFs with known sequences is discussed in this paper.

DNA Methylation Inhibites ANXA1 Gene Expression in Nasopharyngeal Carcinoma Cell Lines*

2009 ◽  
Vol 36 (10) ◽  
pp. 1319-1326 ◽  
Author(s):  
Shuang-Xiang TAN ◽  
Rui-Cheng HU ◽  
Ai-Guo DAI ◽  
Cen-E TANG ◽  
Hong YI ◽  
...  
Keyword(s):  
Gene Expression ◽  
Dna Methylation ◽  
Nasopharyngeal Carcinoma ◽  
Cell Lines ◽  
Carcinoma Cell ◽  
Nasopharyngeal Carcinoma Cell ◽  
Carcinoma Cell Lines
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