scholarly journals Tissue-specific expression and developmental regulation of the human fgr proto-oncogene.

1989 ◽  
Vol 9 (1) ◽  
pp. 92-99 ◽  
Author(s):  
T J Ley ◽  
N L Connolly ◽  
S Katamine ◽  
M S Cheah ◽  
R M Senior ◽  
...  
Keyword(s):  
Transcriptional Activation ◽  
Developmental Regulation ◽  
Constitutive Expression ◽  
U937 Cells ◽  
Induced Differentiation ◽  
Specific Expression ◽  
Normal Peripheral Blood ◽  
Rna Molecules ◽  
Low Levels ◽  
Fgr Gene

In this study, we show that c-fgr proto-oncogene expression is limited to normal peripheral blood granulocytes, monocytes, and alveolar macrophages, all of which contain 50 to 100 copies of c-fgr mRNA per cell. The c-fgr RNA molecules in these cells consisted of partially spliced transcripts containing intron 7 and completely spliced molecules capable of encoding the predicted p55 c-fgr protein. The splicing of intron 7 appeared to occur after the splicing of most of the other introns; partially spliced molecules containing intron 7 did not appear to be transported into the cytoplasm. Very low levels of fgr transcripts were also present in U937 promonocytic cells and increased in abundance with 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced differentiation. The level of fgr transcripts began to increase 2 to 4 h after TPA addition, peaked at 8 h, and subsequently declined. Since we found that the half-life of fgr mRNA was longer than 8 h, these changes are best explained by transient transcriptional activation of fgr during TPA-induced differentiation, although nuclear runoff experiments were not sensitive enough to detect this event. Cycloheximide also caused accumulation of c-fgr transcripts in U937 cells; no superinduction was observed when TPA and cycloheximide were added at the same time. Induction by either agent was blocked with actinomycin D. These results demonstrate that the c-fgr gene is expressed in a tissue- and development-specific fashion and suggest that constitutive expression of c-fgr in U937 cells is regulated by a labile transcriptional repressor.

Tissue-specific expression and developmental regulation of the human fgr proto-oncogene

1989 ◽  
Vol 9 (1) ◽  
pp. 92-99
Author(s):  
T J Ley ◽  
N L Connolly ◽  
S Katamine ◽  
M S Cheah ◽  
R M Senior ◽  
...  
Keyword(s):  
Transcriptional Activation ◽  
Developmental Regulation ◽  
Constitutive Expression ◽  
U937 Cells ◽  
Induced Differentiation ◽  
Specific Expression ◽  
Normal Peripheral Blood ◽  
Rna Molecules ◽  
Low Levels ◽  
Fgr Gene

In this study, we show that c-fgr proto-oncogene expression is limited to normal peripheral blood granulocytes, monocytes, and alveolar macrophages, all of which contain 50 to 100 copies of c-fgr mRNA per cell. The c-fgr RNA molecules in these cells consisted of partially spliced transcripts containing intron 7 and completely spliced molecules capable of encoding the predicted p55 c-fgr protein. The splicing of intron 7 appeared to occur after the splicing of most of the other introns; partially spliced molecules containing intron 7 did not appear to be transported into the cytoplasm. Very low levels of fgr transcripts were also present in U937 promonocytic cells and increased in abundance with 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced differentiation. The level of fgr transcripts began to increase 2 to 4 h after TPA addition, peaked at 8 h, and subsequently declined. Since we found that the half-life of fgr mRNA was longer than 8 h, these changes are best explained by transient transcriptional activation of fgr during TPA-induced differentiation, although nuclear runoff experiments were not sensitive enough to detect this event. Cycloheximide also caused accumulation of c-fgr transcripts in U937 cells; no superinduction was observed when TPA and cycloheximide were added at the same time. Induction by either agent was blocked with actinomycin D. These results demonstrate that the c-fgr gene is expressed in a tissue- and development-specific fashion and suggest that constitutive expression of c-fgr in U937 cells is regulated by a labile transcriptional repressor.

scholarly journals In VivoStudies Suggest that Induction of VanS-Dependent Vancomycin Resistance Requires Binding of the Drug to d-Ala-d-Ala Termini in the Peptidoglycan Cell Wall

2013 ◽  
Vol 57 (9) ◽  
pp. 4470-4480 ◽  
Author(s):  
Min Jung Kwun ◽  
Gabriela Novotna ◽  
Andrew R. Hesketh ◽  
Lionel Hill ◽  
Hee-Jeon Hong
Keyword(s):  
Cell Wall ◽  
Transcriptional Activation ◽  
Streptomyces Coelicolor ◽  
Constitutive Expression ◽  
Transcriptional Response ◽  
Vancomycin Resistance ◽  
Content Type ◽  
Expression Of Genes ◽  
Peptidoglycan Cell Wall

ABSTRACTVanRS two-component regulatory systems are key elements required for the transcriptional activation of inducible vancomycin resistance genes in bacteria, but the precise nature of the ligand signal that activates these systems has remained undefined. Using the resistance system inStreptomyces coelicoloras a model, we have undertaken a series ofin vivostudies which indicate that the VanS sensor kinase in VanB-type resistance systems is activated by vancomycin in complex with thed-alanyl-d-alanine (d-Ala-d-Ala) termini of cell wall peptidoglycan (PG) precursors. Complementation of an essentiald-Ala-d-Ala ligase activity by constitutive expression ofvanAencoding a bifunctionald-Ala-d-Ala andd-alanyl-d-lactate (d-Ala-d-Lac) ligase activity allowed construction of strains that synthesized variable amounts of PG precursors containingd-Ala-d-Ala. Assays quantifying the expression of genes under VanRS control showed that the response to vancomycin in these strains correlated with the abundance ofd-Ala-d-Ala-containing PG precursors; strains producing a lower proportion of PG precursors terminating ind-Ala-d-Ala consistently exhibited a lower response to vancomycin. Pretreatment of wild-type cells with vancomycin or teicoplanin to saturate and mask thed-Ala-d-Ala binding sites in nascent PG also blocked the transcriptional response to subsequent vancomycin exposure, and desleucyl vancomycin, a vancomycin analogue incapable of interacting withd-Ala-d-Ala residues, failed to inducevangene expression. Activation of resistance by a vancomycin–d-Ala-d-Ala PG complex predicts a limit to the proportion of PG that can be derived from precursors terminating ind-Ala-d-Lac, a restriction also enforced by the bifunctional activity of the VanA ligase.

Expression of SMRTβ promotes ligand-induced activation of mutated and wild-type retinoid receptors

Blood ◽  
2004 ◽  
Vol 104 (13) ◽  
pp. 4226-4235 ◽  
Author(s):  
Sylvie Côté ◽  
Suzan McNamara ◽  
Daria Brambilla ◽  
Andrea Bianchini ◽  
Giovanni Rizzo ◽  
...  
Keyword(s):  
Ligand Binding ◽  
Nuclear Receptors ◽  
Transcriptional Activation ◽  
Leukemic Cell ◽  
Wild Type ◽  
Specific Expression ◽  
Retinoid Receptors ◽  
Leukemic Cell Lines ◽  
All Trans Retinoic Acid ◽  
New Evidence

Abstract Nuclear receptors are ligand-modulated transcription factors regulated by interactions with corepressors and coactivators, whose functions are not fully understood. Acute promyelocytic leukemia (APL) is characterized by a translocation, t(15;17), that produces a PML/RARα fusion oncoprotein, whose abnormal transcriptional function is successfully targeted by pharmacologic levels of all-trans-retinoic acid (ATRA). Mutations in the ligand-binding domain of PML/RARα that confer resistance to ATRA have been studied by expression in nonhematopoietic cells, such as Cos-1. Here, we show that ATRA binding and transcriptional activation by the same PML/RARα mutant differ markedly between nonhematopoietic and leukemic cell lines. Differential expression of the corepressor isoform silencing mediator for retinoid and thyroid receptors β (SMRTβ) correlates with increased ligand binding and transcription by the mutant PML/RARα. Transient and stable overexpression of SMRTβ in hematopoietic cells that only express SMRTα increased ATRA binding, ligand-induced transcription, and ATRA-induced cell differentiation. This effect may not be limited to abnormal nuclear receptors, because overexpression of SMRTβ increased ATRA-induced binding and transcriptional activation of wild-type receptors PML/RARα and RARα. Our results suggest a novel role for the SMRTβ isoform whereby its cell-specific expression may influence the binding and transcriptional capacities of nuclear receptors, thus providing new evidence of distinct functions of corepressor isoforms and adding complexity to transcriptional regulation.

A γGT-AT1A receptor transgene protects renal cortical structure in AT1 receptor-deficient mice

2004 ◽  
Vol 18 (3) ◽  
pp. 290-298 ◽  
Author(s):  
Thu H. Le ◽  
Michael I. Oliverio ◽  
Hyung-Suk Kim ◽  
Harmony Salzler ◽  
Rajesh C. Dash ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Transgenic Mice ◽  
Proximal Tubule ◽  
Physiological Role ◽  
Renal Proximal Tubule ◽  
Hypoxanthine Phosphoribosyl Transferase ◽  
Wild Type ◽  
Specific Expression ◽  
Low Levels ◽  
Deficient Mice

To understand the physiological role of angiotensin type 1 (AT1) receptors in the proximal tubule of the kidney, we generated a transgenic mouse line in which the major murine AT1 receptor isoform, AT1A, was expressed under the control of the P1 portion of the γ-glutamyl transpeptidase (γGT) promoter. In transgenic mice, this promoter has been shown to confer cell-specific expression in epithelial cells of the renal proximal tubule. To avoid random integration of multiple copies of the transgene, we used gene targeting to produce mice with a single-copy transgene insertion at the hypoxanthine phosphoribosyl transferase ( Hprt) locus on the X chromosome. The physiological effects of the γGT-AT1A transgene were examined on a wild-type background and in mice with targeted disruption of one or both of the murine AT1 receptor genes ( Agtr1a and Agtr1b). On all three backgrounds, γGT-AT1A transgenic mice were healthy and viable. On the wild-type background, the presence of the transgene did not affect development, blood pressure, or kidney structure. Despite relatively low levels of expression in the proximal tubule, the transgene blunted the increase in renin expression typically seen in AT1-deficient mice and partially rescued the kidney phenotype associated with Agtr1a−/− Agtr1b−/− mice, significantly reducing cortical cyst formation by more than threefold. However, these low levels of cell-specific expression of AT1 receptors in the renal proximal tubule did not increase the low blood pressures or abolish sodium sensitivity, which are characteristic of AT1 receptor-deficient mice. Although our studies do not clearly identify a role for AT1 receptors in the proximal tubules of the kidney in blood pressure homeostasis, they support a major role for these receptors in modulating renin expression and in maintaining structural integrity of the renal cortex.

scholarly journals Promoter-specific regulation of PPARGC1A gene expression in human skeletal muscle

2015 ◽  
Vol 55 (2) ◽  
pp. 159-168 ◽  
Author(s):  
Daniil V Popov ◽  
Evgeny A Lysenko ◽  
Tatiana F Vepkhvadze ◽  
Nadia S Kurochkina ◽  
Pavel A Maknovskii ◽  
...  
Keyword(s):  
Gene Expression ◽  
Skeletal Muscle ◽  
Human Skeletal Muscle ◽  
Stop Codon ◽  
Constitutive Expression ◽  
Alternative Promoter ◽  
Specific Expression ◽  
Post Exercise ◽  
Specific Regulation ◽  
Intensity Of Exercise

The goal of this study was to identify unknown transcription start sites of thePPARGC1A(PGC-1α) gene in human skeletal muscle and investigate the promoter-specific regulation ofPGC-1αgene expression in human skeletal muscle. Ten amateur endurance-trained athletes performed high- and low-intensity exercise sessions (70 min, 70% or 50%o2max). High-throughput RNA sequencing and exon–exon junction mapping were applied to analyse muscle samples obtained at rest and after exercise.PGC-1αpromoter-specific expression and activation of regulators of PGC-1α gene expression (AMPK, p38 MAPK, CaMKII, PKA and CREB1) after exercise were evaluated using qPCR and western blot. Our study has demonstrated that during post-exercise recovery, human skeletal muscle expresses thePGC-1αgene via two promoters only. As previously described, the additional exon 7a that contains a stop codon was found in all samples. Importantly, only minor levels of other splice site variants were found (and not in all samples). Constitutive expressionPGC-1αgene occurs via the canonical promoter, independent of exercise intensity and exercise-induced increase of AMPKThr172phosphorylation level. Expression ofPGC-1αgene via the alternative promoter is increased of two orders after exercise. This post-exercise expression is highly dependent on the intensity of exercise. There is an apparent association between expression via the alternative promoter and activation of CREB1.

Developmental stage- and spermatogenic cycle-specific expression of transcription factor GATA-1 in mouse Sertoli cells

Development ◽  
1994 ◽  
Vol 120 (7) ◽  
pp. 1759-1766 ◽  
Author(s):  
K. Yomogida ◽  
H. Ohtani ◽  
H. Harigae ◽  
E. Ito ◽  
Y. Nishimune ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Developmental Stage ◽  
Sertoli Cell ◽  
Germ Cells ◽  
Sertoli Cells ◽  
Transcriptional Activation ◽  
Germ Line ◽  
Mouse Testis ◽  
Seminiferous Tubules ◽  
Specific Expression

GATA-1 is an essential factor for the transcriptional activation of erythroid-specific genes, and is also abundantly expressed in a discrete subset of cells bordering the seminiferous epithelium in tubules of the murine testis. In examining normal and germ-line defective mutant mice, we show here that GATA-1 is expressed only in the Sertoli cell lineage in mouse testis. GATA-1 expression in Sertoli cells is induced concomitantly with the first wave of spermatogenesis, and GATA-1-positive cells are uniformly distributed among all tubules during prepubertal testis development. However, the number of GATA-1-positive cells declines thereafter and were found only in the peripheral zone of seminiferous tubules in stages VII, VIII and IX of spermatogenesis in the adult mouse testis. In contrast, virtually every Sertoli cell in mutant W/Wv, jsd/jsd or cryptorchid mice (all of which lack significant numbers of germ cells) expresses GATA-1, thus showing that the expression of this transcription factor is negatively controlled by the maturing germ cells. These observations suggest that transcription factor GATA-1 is a developmental stage- and spermatogenic cycle-specific regulator of gene expression in Sertoli cells.

scholarly journals Characteristics and Expression Pattern of MYC Genes in Triticum aestivum, Oryza sativa, and Brachypodium distachyon

Plants ◽  
2019 ◽  
Vol 8 (8) ◽  
pp. 274 ◽  
Author(s):  
Shoukun Chen ◽  
Hongyan Zhao ◽  
Tengli Luo ◽  
Yue Liu ◽  
Xiaojun Nie ◽  
...  
Keyword(s):  
Transcriptional Activation ◽  
Leucine Zipper ◽  
Brachypodium Distachyon ◽  
Expression Patterns ◽  
Terminal Region ◽  
Gene Promoters ◽  
Interaction Domain ◽  
Specific Expression ◽  
Systematic Analysis ◽  
Transcriptional Activation Domain

Myelocytomatosis oncogenes (MYC) transcription factors (TFs) belong to basic helix-loop-helix (bHLH) TF family and have a special bHLH_MYC_N domain in the N-terminal region. Presently, there is no detailed and systematic analysis of MYC TFs in wheat, rice, and Brachypodium distachyon. In this study, 26 TaMYC, 7 OsMYC, and 7 BdMYC TFs were identified and their features were characterized. Firstly, they contain a JAZ interaction domain (JID) and a putative transcriptional activation domain (TAD) in the bHLH_MYC_N region and a BhlH region in the C-terminal region. In some cases, the bHLH region is followed by a leucine zipper region; secondly, they display tissue-specific expression patterns: wheat MYC genes are mainly expressed in leaves, rice MYC genes are highly expressed in stems, and B. distachyon MYC genes are mainly expressed in inflorescences. In addition, three types of cis-elements, including plant development/growth-related, hormone-related, and abiotic stresses-related were identified in different MYC gene promoters. In combination with the previous studies, these results indicate that MYC TFs mainly function in growth and development, as well as in response to stresses. This study laid a foundation for the further functional elucidation of MYC genes.

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