scholarly journals Splice-Junction Elements and Intronic Sequences Regulate Alternative Splicing of the Drosophila Myosin Heavy Chain Gene Transcript

Genetics ◽  
1997 ◽  
Vol 147 (2) ◽  
pp. 725-741 ◽  
Author(s):  
David M Standiford ◽  
Mary Beth Davis ◽  
Weitao Sun ◽  
Charles P Emerson
Keyword(s):  
Alternative Splicing ◽  
Myosin Heavy Chain ◽  
Heavy Chain ◽  
Mutational Analysis ◽  
Regulatory Elements ◽  
Alternative Exon ◽  
Chain Gene ◽  
Gene Transcript ◽  
Specific Alternative ◽  
Exon 11

The Drosophila muscle myosin heavy chain (Mhc) gene primary transcript contains five alternatively spliced exon groups (exons 3, 7, 9, 11 and 15), each of which contains two to five mutually exclusive members. Individual muscles typically select a specific alternative exon from each group for incorporation into the processed message. We report here on the cis-regulatory mechanisms that direct the processing of alternative exons in Mhc exon 11 in individual muscles using transgenic reporter constructs, RT-PCR and directed mutagenesis. The 6.0-kilobase exon 11 domain is sufficient to direct the correct processing of exon 11 alternatives, demonstrating that the alternative splicing cis-regulatory elements are local to Mhc exon 11. Mutational analysis of Mhc exon 11 reveals that the alternative exon nonconsensus 5′-splice donors are essential for alternative splicing regulation in general, but do not specify alternative exons for inclusion in individual muscles. Rather, we show, through exon substitutions and deletion analyses, that a 360-nucleotide intronic domain precisely directs the normal processing of one exon, Mhc exon 11e, in the indirect flight muscle. These and other data indicate that alternative exons are regulated in appropriate muscles through interactions between intronic alternative splice-specificity elements, nonconsensus exon 11 splice donors and, likely, novel exon-specific alternative splicing factors.

Positive and Negative Intronic Regulatory Elements Control Muscle-Specific Alternative Exon Splicing of Drosophila Myosin Heavy Chain Transcripts

Genetics ◽  
2001 ◽  
Vol 157 (1) ◽  
pp. 259-271 ◽  
Author(s):  
David M Standiford ◽  
Wei Tao Sun ◽  
Mary Beth Davis ◽  
Charles P Emerson
Keyword(s):  
Myosin Heavy Chain ◽  
Heavy Chain ◽  
Regulatory Element ◽  
Regulatory Elements ◽  
Alternative Exon ◽  
Regulatory Sequences ◽  
Splice Donor ◽  
Transgenic Expression ◽  
Specific Alternative ◽  
Exon 11

Abstract Alternative splicing of Drosophila muscle myosin heavy chain (MHC) transcripts is precisely regulated to ensure the expression of specific MHC isoforms required for the distinctive contractile activities of physiologically specialized muscles. We have used transgenic expression analysis in combination with mutagenesis to identify cis-regulatory sequences that are required for muscle-specific splicing of exon 11, which is encoded by five alternative exons that produce alternative “converter” domains in the MHC head. Here, we report the identification of three conserved intronic elements (CIE1, -2, and -3) that control splicing of exon 11e in the indirect flight muscle (IFM). Each of these CIE elements has a distinct function: CIE1 acts as a splice repressor, while CIE2 and CIE3 behave as splice enhancers. These CIE elements function in combination with a nonconsensus splice donor to direct IFM-specific splicing of exon 11e. An additional cis-regulatory element that is essential in coordinating the muscle-specific splicing of other alternative exon 11s is identified. Therefore, multiple interacting intronic and splice donor elements establish the muscle-specific splicing of alternative exon 11s.

scholarly journals Functional domains of the Drosophila melanogaster muscle myosin heavy-chain gene are encoded by alternatively spliced exons.

1989 ◽  
Vol 9 (7) ◽  
pp. 2957-2974 ◽  
Author(s):  
E L George ◽  
M B Ober ◽  
C P Emerson
Keyword(s):  
Myosin Heavy Chain ◽  
Heavy Chain ◽  
Rna Splicing ◽  
Single Copy ◽  
Alternative Exon ◽  
Chain Gene ◽  
Drosophila Genome ◽  
Alternatively Spliced ◽  
Muscle Myosin ◽  
Exon Structure

The single-copy Drosophila muscle myosin heavy-chain (MHC) gene, located at 36B(2L), has a complex exon structure that produces a diversity of larval and adult muscle MHC isoforms through regulated alternative RNA splicing. Genomic and cDNA sequence analyses revealed that this 21-kilobase MHC gene encodes these MHC isoforms in 19 exons. However, five sets of these exons, encoding portions of the S1 head and the hinge domains of the MHC protein, are tandemly repeated as two, three, four, or five divergent copies, which are individually spliced into RNA transcripts. RNA hybridization studies with exon-specific probes showed that at least 10 of the 480 possible MHC isoforms that could arise by alternative RNA splicing of these exons are expressed as MHC transcripts and that the expression of specific members of alternative exon sets is regulated, both in stage and in muscle-type specificity. This regulated expression of specific exons is of particular interest because the alternatively spliced exon sets encode discrete domains of the MHC protein that likely contribute to the specialized contractile activities of different Drosophila muscle types. The alternative exon structure of the Drosophila MHC gene and the single-copy nature of this gene in the Drosophila genome make possible transgenic experiments to test the physiological functions of specific MHC protein domains and genetic and molecular experiments to investigate the mechanisms that regulate alternative exon splicing of MHC and other muscle gene transcripts.

scholarly journals Multiple positive and negative 5' regulatory elements control the cell-type-specific expression of the embryonic skeletal myosin heavy-chain gene.

1987 ◽  
Vol 7 (12) ◽  
pp. 4377-4389 ◽  
Author(s):  
P F Bouvagnet ◽  
E E Strehler ◽  
G E White ◽  
M A Strehler-Page ◽  
B Nadal-Ginard ◽  
...  
Keyword(s):  
Myosin Heavy Chain ◽  
Heavy Chain ◽  
Dna Sequences ◽  
Transcription Initiation ◽  
Simian Virus 40 ◽  
Muscle Cells ◽  
Regulatory Elements ◽  
Simian Virus ◽  
Chain Gene ◽  
Specific Element

To identify the DNA sequences that regulate the expression of the sarcomeric myosin heavy-chain (MHC) genes in muscle cells, a series of deletion constructs of the rat embryonic MHC gene was assayed for transient expression after introduction into myogenic and nonmyogenic cells. The sequences in 1.4 kilobases of 5'-flanking DNA were found to be sufficient to direct expression of the MHC gene constructs in a tissue-specific manner (i.e., in differentiated muscle cells but not in undifferentiated muscle and nonmuscle cells). Three main distinct regulatory domains have been identified: (i) the upstream sequences from positions -1413 to -174, which determine the level of expression of the MHC gene and are constituted of three positive regulatory elements and two negative ones; (ii) a muscle-specific regulatory element from positions -173 to -142, which restricts the expression of the MHC gene to muscle cells; and (iii) the promoter region, downstream from position -102, which directs transcription initiation. Introduction of the simian virus 40 enhancer into constructs where subportions of or all of the upstream sequences are deleted (up to position -173) strongly increases the level of expression of such truncated constructs but without changing their muscle specificity. These upstream sequences, which can be substituted for by the simian virus 40 enhancer, function in an orientation-, position-, and promoter-dependent fashion. The muscle-specific element is also promoter specific but does not support efficient expression of the MHC gene. The MHC promoter in itself is not muscle specific. These results underline the importance of the concerted action of multiple regulatory elements that are likely to represent targets for DNA-binding-regulatory proteins.

scholarly journals A conserved GATA motif in a tissue-specific DNase I hypersensitive site of the cardiac α-myosin heavy chain gene

1997 ◽  
Vol 325 (1) ◽  
pp. 47-51 ◽  
Author(s):  
Weei-Yuarn HUANG ◽  
Choong-Chin LIEW
Keyword(s):  
Myosin Heavy Chain ◽  
Heavy Chain ◽  
Developmental Stages ◽  
Regulatory Elements ◽  
Dnase I ◽  
Upstream Region ◽  
Chain Gene ◽  
Nuclear Extracts ◽  
Hypersensitive Sites ◽  
Gata Motif

Transgenic analysis has indicated that far upstream regulatory elements of the cardiac α-myosin heavy chain (MyHC) gene are required for appropriate transgene expression [Subramaniam, Gulick, Neumann, Knotts and Robbins (1993) J. Biol. Chem. 268, 4331–4336]. In an attempt to identify these as-yet-undefined regulatory elements, we mapped the DNase I hypersensitive sites (DHSs) in the 4 kb upstream region of the hamster cardiac α-MyHC gene. When using nuclei isolated from late-gestational and adult heart ventricles, a strong DHS was identified in the -1.9 kb region (α-1.9 kb site). It cannot be detected in kidney, liver or cardiofibroblast nuclei. Within this site, we found a conserved GATA-motif that interacts specifically with GATA-binding factors in nuclear extracts of cardiomyocytes at various developmental stages. These data provide further evidence to support the role of GATA factors in the regulation of cardiac α-MyHC gene expression.

Functional domains of the Drosophila melanogaster muscle myosin heavy-chain gene are encoded by alternatively spliced exons

1989 ◽  
Vol 9 (7) ◽  
pp. 2957-2974
Author(s):  
E L George ◽  
M B Ober ◽  
C P Emerson
Keyword(s):  
Myosin Heavy Chain ◽  
Heavy Chain ◽  
Rna Splicing ◽  
Single Copy ◽  
Alternative Exon ◽  
Chain Gene ◽  
Drosophila Genome ◽  
Alternatively Spliced ◽  
Muscle Myosin ◽  
Exon Structure

The single-copy Drosophila muscle myosin heavy-chain (MHC) gene, located at 36B(2L), has a complex exon structure that produces a diversity of larval and adult muscle MHC isoforms through regulated alternative RNA splicing. Genomic and cDNA sequence analyses revealed that this 21-kilobase MHC gene encodes these MHC isoforms in 19 exons. However, five sets of these exons, encoding portions of the S1 head and the hinge domains of the MHC protein, are tandemly repeated as two, three, four, or five divergent copies, which are individually spliced into RNA transcripts. RNA hybridization studies with exon-specific probes showed that at least 10 of the 480 possible MHC isoforms that could arise by alternative RNA splicing of these exons are expressed as MHC transcripts and that the expression of specific members of alternative exon sets is regulated, both in stage and in muscle-type specificity. This regulated expression of specific exons is of particular interest because the alternatively spliced exon sets encode discrete domains of the MHC protein that likely contribute to the specialized contractile activities of different Drosophila muscle types. The alternative exon structure of the Drosophila MHC gene and the single-copy nature of this gene in the Drosophila genome make possible transgenic experiments to test the physiological functions of specific MHC protein domains and genetic and molecular experiments to investigate the mechanisms that regulate alternative exon splicing of MHC and other muscle gene transcripts.

scholarly journals Multiple muscle-specific regulatory elements are associated with a DNase I hypersensitive site of the cardiac β-myosin heavy-chain gene

1997 ◽  
Vol 327 (2) ◽  
pp. 507-512 ◽  
Author(s):  
Weei-Yuarn HUANG ◽  
Jin-Jer CHEN ◽  
N.-L. SHIH ◽  
Choong-Chin LIEW
Keyword(s):  
Myosin Heavy Chain ◽  
Heavy Chain ◽  
Specific Interaction ◽  
Regulatory Elements ◽  
Dnase I ◽  
Proximal Promoter ◽  
Upstream Region ◽  
Chain Gene ◽  
Kinase Gene ◽  
Mouse Muscle

Using nuclei isolated from neonatal cardiomyocytes, we have mapped the DNase I hypersensitive sites (DHSs) residing within the 5ʹ-upstream regions of the hamster cardiac myosin heavy-chain (MyHC) gene. Two cardiac-specific DHSs within the 5 kb upstream region of the cardiac MyHC gene were identified. One of the DHSs was mapped to the -2.3 kb (β-2.3 kb) region and the other to the proximal promoter region. We further localized the β-2.3 kb site to a range of 250 bp. Multiple, conserved, muscle regulatory motifs were found within the β-2.3 kb site, consisting of three E-boxes, one AP-2 site, one CArG motif, one CT/ACCC box and one myocyte-specific enhancer factor-2 site. This cluster of regulatory elements is strikingly similar to a cluster found in the enhancer of the mouse muscle creatine kinase gene (-1256 to -1050). The specific interaction of the motifs within the β-2.3 kb site and the cardiac nuclear proteins was demonstrated using gel mobility-shift assays and footprinting analysis. In addition, transfection analysis revealed a significant increase in chloramphenicol acetyltransferase activity when the β-2.3 kb site was linked to a heterologous promoter. These results suggest that previously undefined regulatory elements of the β-MyHC gene may be associated with the β-2.3 kb site.

Transcriptional regulation of the type I myosin heavy chain gene in denervated rat soleus

2003 ◽  
Vol 284 (3) ◽  
pp. C738-C748 ◽  
Author(s):  
K. A. Huey ◽  
F. Haddad ◽  
A. X. Qin ◽  
K. M. Baldwin
Keyword(s):  
Myosin Heavy Chain ◽  
Heavy Chain ◽  
Molecular Mechanisms ◽  
Mutational Analysis ◽  
Chain Gene ◽  
Type I ◽  
Slow Type ◽  
Actin Promoter ◽  
Mrna Analysis

Denervation (DEN) of rat soleus is associated with a decreased expression of slow type I myosin heavy chain (MHC) and an increased expression of the faster MHC isoforms. The molecular mechanisms behind these shifts remain unclear. We first investigated endogenous transcriptional activity of the type I MHC gene in normal and denervated soleus muscles via pre-mRNA analysis. Our results suggest that the type I MHC gene is regulated via transcriptional processes in the denervated soleus. Deletion and mutational analysis of the rat type I MHC promoter was then used to identify cis elements or regions of the promoter involved in this response. DEN significantly decreased in vivo activity of the −3,500, −2,500, −914, −408, −299, and −215 bp type I MHC promoters, relative to the α-skeletal actin promoter. In contrast, normalized −171 promoter activity was unchanged. Mutation of the βe3 element (−214/−190) in the −215 promoter and deletion of this element (−171 promoter) blunted type I downregulation with DEN. In contrast, βe3 mutation in the −408 promoters was not effective in attenuating the DEN response, suggesting the existence of additional DEN-responsive sites between −408 and −215. Western blotting and gel mobility supershift assays demonstrated decreased expression and DNA binding of transcription enhancer factor 1 (TEF-1) with DEN, suggesting that this decrease may contribute to type I MHC downregulation in denervated muscle.

Cushing’s syndrome in early infancy due to isolated sporadic bilateral micronodular adrenocortical disease associated with myosin heavy chain 8 mutation: diagnostic challenges, too many!

2020 ◽  
Vol 13 (10) ◽  
pp. e236850
Author(s):  
Sananda Majumder ◽  
Partha Pratim Chakraborty ◽  
Prakash Chandra Ghosh ◽  
Mitali Bera
Keyword(s):  
Myosin Heavy Chain ◽  
Cushing’S Syndrome ◽  
Heavy Chain ◽  
Mutational Analysis ◽  
Carney Complex ◽  
Cushing's Syndrome ◽  
Chromosome 17 ◽  
Chain Gene ◽  
High Dose ◽  
Diagnostic Challenge

Endogenous Cushing’s syndrome (CS) is rare in infancy. Bilateral micronodular adrenocortical disease (BMAD), either primary pigmented nodular adrenocortical disease or the non-pigmented isolated micronodular adrenocortical disease is an important aetiology of CS in this age group, which requires bilateral adrenalectomy for cure. BMAD may be isolated, or a component of Carney complex. Isolated sporadic BMAD without other systemic manifestations poses a diagnostic challenge. Paradoxical cortisol response to dexamethasone suggests, while adrenal histopathology and mutational analysis of the culprit genes confirm BMAD. BMAD was suspected in 6-year-old infant with midnormal adrenocorticotrophic hormone, inconclusive adrenal and pituitary imaging and paradoxical increase in cortisol following high dose of dexamethasone. Exome sequencing revealed heterozygous c.354+1G>C (5′ splice site) variant in the myosin heavy chain gene (MYH8), located in chromosome 17. This particular variant has not been reported in the literature. In view of suspected phenotype and its absence in the population databases, the variant was classified as pathogenic.

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