scholarly journals Characterization of two atypical promoters and alternate mRNA processing in the mouse Thy-1.2 glycoprotein gene.

1986 ◽  
Vol 6 (8) ◽  
pp. 2923-2931 ◽  
Author(s):  
H A Ingraham ◽  
G A Evans

The promoter and 5' flanking region of the mouse Thy-1.2 glycoprotein gene were characterized by DNA sequencing, primer extension analysis, and deletion analysis. Transcriptional initiation sites were identified which corresponded to two separate exons upstream of the portion of the gene encoding the Thy-1.2 glycoprotein. We demonstrated that the mouse Thy-1.2 gene was transcribed from two atypical promoters separated by 260 base pairs in the genomic sequence. These promoters contained neither TATAAG nor GGPyCCAATCT homologous sequences but defined a conserved nonamer CTCCCTGCT at -48 from each initiation site. Two Thy-1.2 mRNA species of 1,835 and 1,939 nucleotides, differing in the 5' untranslated region of the mRNA, were thus transcribed from the single Thy-1.2 gene by mRNA splicing to the same downstream exon. Recombinant genomes in which the bacterial chloramphenicol acetyltransferase gene was expressed from either of the two Thy-1.2 promoters demonstrated that each promoter functioned independently and did not direct cell-specific expression in lymphoid cells. The 5' flanking region of the Thy-1.2 gene upstream of -68 could be eliminated without altering cell-type-specific expression. This suggests that regulatory elements responsible for tissue and developmental stage-specific expression of the Thy-1.2 gene are not present in the 5' flanking DNA but may reside downstream of the promoters.

1986 ◽  
Vol 6 (8) ◽  
pp. 2923-2931
Author(s):  
H A Ingraham ◽  
G A Evans

The promoter and 5' flanking region of the mouse Thy-1.2 glycoprotein gene were characterized by DNA sequencing, primer extension analysis, and deletion analysis. Transcriptional initiation sites were identified which corresponded to two separate exons upstream of the portion of the gene encoding the Thy-1.2 glycoprotein. We demonstrated that the mouse Thy-1.2 gene was transcribed from two atypical promoters separated by 260 base pairs in the genomic sequence. These promoters contained neither TATAAG nor GGPyCCAATCT homologous sequences but defined a conserved nonamer CTCCCTGCT at -48 from each initiation site. Two Thy-1.2 mRNA species of 1,835 and 1,939 nucleotides, differing in the 5' untranslated region of the mRNA, were thus transcribed from the single Thy-1.2 gene by mRNA splicing to the same downstream exon. Recombinant genomes in which the bacterial chloramphenicol acetyltransferase gene was expressed from either of the two Thy-1.2 promoters demonstrated that each promoter functioned independently and did not direct cell-specific expression in lymphoid cells. The 5' flanking region of the Thy-1.2 gene upstream of -68 could be eliminated without altering cell-type-specific expression. This suggests that regulatory elements responsible for tissue and developmental stage-specific expression of the Thy-1.2 gene are not present in the 5' flanking DNA but may reside downstream of the promoters.


1994 ◽  
Vol 301 (3) ◽  
pp. 835-845 ◽  
Author(s):  
Z Y Zhang-Keck ◽  
M Srivastava ◽  
C A Kozak ◽  
H Caohuy ◽  
A Shirvan ◽  
...  

We have isolated and characterized the gene encoding mouse synexin, which consists of 14 exons and spans approximately 30 kbp of genomic DNA. The protein's unique N-terminal domain is encoded by six exons, and the C-terminal tetrad repeat, the site of the membrane-fusion and ion-channel domain, is encoded by seven exons. The first exon encodes the 5′-untranslated region. Analysis of synexin-gene expression in different mouse tissues shows that mRNA with exon 6 is only present in brain, heart and skeletal muscle. mRNA lacking exon 6 is expressed in all tissues we have examined. The initiation site for transcription was determined by primer-extension analysis and S1 nuclease mapping. Sequence analysis of the 1.3 kb 5′-flanking region revealed that the promoter has a TATA box located at position -25 and a number of potential promoter and regulatory elements. A CCAAT motif was not observed but CCATT is located in an appropriate position for the CCAAT motif upstream from the transcription-initiation start site. In addition, the 5′-flanking region contains two sets of palindromic sequences. Finally, we have determined that the functional synexin gene (Anx7) is located on mouse chromosome 14 and that a pseudogene (Anx7-ps1) is located on chromosome 10.


1988 ◽  
Vol 8 (3) ◽  
pp. 1113-1122 ◽  
Author(s):  
E Czarnecka ◽  
R T Nagao ◽  
J L Key ◽  
W B Gurley

We determined the DNA sequence and mapped the corresponding transcripts of a genomic clone containing the Gmhsp26-A gene of soybean. This gene is homologous to the previously characterized cDNA clone pCE54 (E. Czarnecka, L. Edelman, F. Schöffl, and J. L. Key, Plant Mol. Biol. 3:45-58, 1984) and is expressed in response to a wide variety of physiological stresses including heat shock (HS). S1 nuclease mapping of transcripts and a comparison of the cDNA sequence with the genomic sequence indicated the presence of a soybean seedlings with either CdCl2 or CuSO4. Analysis of the 5' termini of transcripts indicated the presence of one major and at least two minor start sites. In each case, initiation occurred 27 to 30 base pairs downstream from a TATA-like motif, and thus each initiation site appears to be promoted by the activity of a separate subpromoter. The three subpromoters are all associated with sequences showing low homology to the HS consensus element of Drosophila melanogaster HS genes and are differentially induced in response to various stresses. Within the carboxyl-terminal half of the protein, hydropathy analysis of the deduced amino acid sequence indicated a high degree of relatedness to the small HS proteins. A comparison of the primary amino acid sequence of hsp26-A with sequences of the small HS proteins suggested that this stress protein is highly diverged and may therefore be specialized for stress adaptation in soybean.


1988 ◽  
Vol 8 (7) ◽  
pp. 2896-2909 ◽  
Author(s):  
E A Sternberg ◽  
G Spizz ◽  
W M Perry ◽  
D Vizard ◽  
T Weil ◽  
...  

Terminal differentiation of skeletal myoblasts is accompanied by induction of a series of tissue-specific gene products, which includes the muscle isoenzyme of creatine kinase (MCK). To begin to define the sequences and signals involved in MCK regulation in developing muscle cells, the mouse MCK gene has been isolated. Sequence analysis of 4,147 bases of DNA surrounding the transcription initiation site revealed several interesting structural features, some of which are common to other muscle-specific genes and to cellular and viral enhancers. To test for sequences required for regulated expression, a region upstream of the MCK gene from -4800 to +1 base pairs, relative to the transcription initiation site, was linked to the coding sequences of the bacterial chloramphenicol acetyltransferase (CAT) gene. Introduction of this MCK-CAT fusion gene into C2 muscle cells resulted in high-level expression of CAT activity in differentiated myotubes and no detectable expression in proliferating undifferentiated myoblasts or in nonmyogenic cell lines. Deletion mutagenesis of sequences between -4800 and the transcription start site showed that the region between -1351 and -1050 was sufficient to confer cell type-specific and developmentally regulated expression on the MCK promoter. This upstream regulatory element functioned independently of position, orientation, or distance from the promoter and therefore exhibited the properties of a classical enhancer. This upstream enhancer also was able to confer muscle-specific regulation on the simian virus 40 promoter, although it exhibited a 3- to 5-fold preference for its own promoter. In contrast to the cell type- and differentiation-specific expression of the upstream enhancer, the MCK promoter was able to function in myoblasts and myotubes and in nonmyogenic cell lines when combined with the simian virus 40 enhancer. An additional positive regulatory element was identified within the first intron of the MCK gene. Like the upstream enhancer, this intragenic element functioned independently of position, orientation, and distance with respect to the MCK promoter and was active in differentiated myotubes but not in myoblasts. These results demonstrate that expression of the MCK gene in developing muscle cells is controlled by complex interactions among multiple upstream and intragenic regulatory elements that are functional only in the appropriate cellular context.


2018 ◽  
Vol 41 (1) ◽  
pp. 323-348 ◽  
Author(s):  
Claire N. Bedbrook ◽  
Benjamin E. Deverman ◽  
Viviana Gradinaru

Recombinant viruses allow for targeted transgene expression in specific cell populations throughout the nervous system. The adeno-associated virus (AAV) is among the most commonly used viruses for neuroscience research. Recombinant AAVs (rAAVs) are highly versatile and can package most cargo composed of desired genes within the capsid's ∼5-kb carrying capacity. Numerous regulatory elements and intersectional strategies have been validated in rAAVs to enable cell type–specific expression. rAAVs can be delivered to specific neuronal populations or globally throughout the animal. The AAV capsids have natural cell type or tissue tropism and trafficking that can be modified for increased specificity. Here, we describe recently engineered AAV capsids and associated cargo that have extended the utility of AAVs in targeting molecularly defined neurons throughout the nervous system, which will further facilitate neuronal circuit interrogation and discovery.


1988 ◽  
Vol 8 (3) ◽  
pp. 1113-1122
Author(s):  
E Czarnecka ◽  
R T Nagao ◽  
J L Key ◽  
W B Gurley

We determined the DNA sequence and mapped the corresponding transcripts of a genomic clone containing the Gmhsp26-A gene of soybean. This gene is homologous to the previously characterized cDNA clone pCE54 (E. Czarnecka, L. Edelman, F. Schöffl, and J. L. Key, Plant Mol. Biol. 3:45-58, 1984) and is expressed in response to a wide variety of physiological stresses including heat shock (HS). S1 nuclease mapping of transcripts and a comparison of the cDNA sequence with the genomic sequence indicated the presence of a soybean seedlings with either CdCl2 or CuSO4. Analysis of the 5' termini of transcripts indicated the presence of one major and at least two minor start sites. In each case, initiation occurred 27 to 30 base pairs downstream from a TATA-like motif, and thus each initiation site appears to be promoted by the activity of a separate subpromoter. The three subpromoters are all associated with sequences showing low homology to the HS consensus element of Drosophila melanogaster HS genes and are differentially induced in response to various stresses. Within the carboxyl-terminal half of the protein, hydropathy analysis of the deduced amino acid sequence indicated a high degree of relatedness to the small HS proteins. A comparison of the primary amino acid sequence of hsp26-A with sequences of the small HS proteins suggested that this stress protein is highly diverged and may therefore be specialized for stress adaptation in soybean.


2019 ◽  
Vol 20 (8) ◽  
pp. 1845 ◽  
Author(s):  
Vichithra R.B. Liyanage ◽  
Carl O. Olson ◽  
Robby M. Zachariah ◽  
James R. Davie ◽  
Mojgan Rastegar

Methyl CpG binding protein-2 (MeCP2) isoforms (E1 and E2) are important epigenetic regulators in brain cells. Accordingly, MeCP2 loss- or gain-of-function mutation causes neurodevelopmental disorders, including Rett syndrome (RTT), MECP2 duplication syndrome (MDS), and autism spectrum disorders (ASD). Within different types of brain cells, highest MeCP2 levels are detected in neurons and the lowest in astrocytes. However, our current knowledge of Mecp2/MeCP2 regulatory mechanisms remains largely elusive. It appears that there is a sex-dependent effect in X-linked MeCP2-associated disorders, as RTT primarily affects females, whereas MDS is found almost exclusively in males. This suggests that Mecp2 expression levels in brain cells might be sex-dependent. Here, we investigated the sex- and cell type-specific expression of Mecp2 isoforms in male and female primary neurons and astrocytes isolated from the murine forebrain. Previously, we reported that DNA methylation of six Mecp2 regulatory elements correlated with Mecp2 levels in the brain. We now show that in male brain cells, DNA methylation is significantly correlated with the transcript expression of these two isoforms. We show that both Mecp2 isoforms are highly expressed in male neurons compared to male astrocytes, with Mecp2e1 expressed at higher levels than Mecp2e2. Our data indicate that higher DNA methylation at the Mecp2 regulatory element(s) is associated with lower levels of Mecp2 isoforms in male astrocytes compared to male neurons.


Microbiology ◽  
2014 ◽  
Vol 160 (8) ◽  
pp. 1618-1627 ◽  
Author(s):  
Ci Fu ◽  
Asuma Tanaka ◽  
Stephen J. Free

The Neurospora crassa genome encodes two 1,3-α-glucan synthases. One of these 1,3-α-glucan synthase genes, ags-1, was shown to be required for the synthesis of 1,3-α-glucan in the aerial hyphae and macroconidia cell walls. 1,3-α-Glucan was found in the conidia cell wall, but was absent from the vegetative hyphae cell wall. Deletion of ags-1 affected conidial development. Δags-1 produced only 5 % as many conidia as the WT and most of the conidia produced by Δags-1 were not viable. The ags-1 upstream regulatory elements were shown to direct cell-type-specific expression of red fluorescent protein in conidia and aerial hyphae. A haemagglutinin-tagged AGS-1 was found to be expressed in aerial hyphae and conidia. The research showed that 1,3-α-glucan is an aerial hyphae and conidia cell wall component, and is required for normal conidial differentiation.


2003 ◽  
Vol 370 (3) ◽  
pp. 771-784 ◽  
Author(s):  
Cristina PÉREZ-GÓMEZ ◽  
José M. MATÉS ◽  
Pedro M. GÓMEZ-FABRE ◽  
Antonio del CASTILLO-OLIVARES ◽  
Francisco J. ALONSO ◽  
...  

In mammals, glutaminase (GA) is expressed in most tissues, but the regulation of organ-specific expression is largely unknown. Therefore, as an essential step towards studying the regulation of GA expression, the human liver-type GA (hLGA) gene has been characterized. LGA genomic sequences were isolated using the genome walking technique. Analysis and comparison of these sequences with two LGA cDNA clones and the Human Genome Project database, allowed the determination of the genomic organization of the LGA gene. The gene has 18 exons and is approx. 18kb long. All exon/intron junction sequences conform to the GT/AG rule. Progressive deletion analysis of LGA promoter—luciferase constructs indicated that the core promoter is located between nt −141 and +410, with several potential regulatory elements: CAAT, GC, TATA-like, Ras-responsive element binding protein and specificity protein 1 (Sp1) sites. The minimal promoter was mapped within +107 and +410, where only an Sp1 binding site is present. Mutation experiments suggested that two CAAT recognition elements near the transcription-initiation site (-138 and −87), play a crucial role for optimal promoter activity. Electrophoretic mobility-shift assays confirmed the importance of CAAT- and TATA-like boxes to enhance basal transcription, and demonstrated that HNF-1 motif is a significant distal element for transcriptional regulation of the hLGA gene.


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