Molecular properties of cardiac tail-anchored membrane protein SLMAP are consistent with structural role in arrangement of excitation-contraction coupling apparatus

2005 ◽  
Vol 288 (4) ◽  
pp. H1810-H1819 ◽  
Author(s):  
Rosa M. Guzzo ◽  
Maysoon Salih ◽  
Edwin D. Moore ◽  
Balwant S. Tuana
Keyword(s):  
Potential Role ◽  
Cardiac Myocyte ◽  
Interaction Analysis ◽  
Coiled Coil ◽  
Spatial Arrangement ◽  
Coupling Mechanism ◽  
Developmentally Regulated ◽  
Specific Expression ◽  
Molecular Determinants ◽  
Effective Excitation

The spatial arrangement of the cell-surface membranes (sarcolemma and transverse tubules) and internal membranes of the sarcoplasmic reticulum relative to the myofibril is critical for effective excitation-contraction (E-C) coupling in cardiac myocytes; however, the molecular determinants of this order remain to be defined. Here, we ascribe molecular and cellular properties to the coiled-coil, tail-anchored sarcolemmal membrane-associated protein (SLMAP) that are consistent with a potential role in organizing the E-C coupling apparatus of the cardiomyocyte. The expression of SLMAP was developmentally regulated and its localization was distinctly apparent at the level of the membranes involved in regulating the E-C coupling mechanism. Several SLMAP isoforms were expressed in the cardiac myocyte with unique COOH-terminal membrane anchors that could target this molecule to distinct subcellular membranes. Protein interaction analysis indicated that SLMAPs could self assemble and bind myosin in cardiac muscle. The cardiac-specific expression of SLMAP isoforms that can be targeted to distinct subcellular membranes, self assemble, and interact with the myofibril suggests a potential role for this molecule in the structural arrangement of the E-C coupling apparatus.

scholarly journals Function of Circular RNAs in Fish and Their Potential Application as Biomarkers

2021 ◽  
Vol 22 (13) ◽  
pp. 7119
Author(s):  
Golam Rbbani ◽  
Artem Nedoluzhko ◽  
Jorge Galindo-Villegas ◽  
Jorge M. O. Fernandes
Keyword(s):  
Growth Regulation ◽  
Functional Characterization ◽  
Circular Rnas ◽  
Farmed Fish ◽  
Developmentally Regulated ◽  
Specific Expression ◽  
Cell Type Specific Expression ◽  
Cell Type Specific ◽  
Taxonomic Groups ◽  
And Function

Circular RNAs (circRNAs) are an emerging class of regulatory RNAs with a covalently closed-loop structure formed during pre-mRNA splicing. Recent advances in high-throughput RNA sequencing and circRNA-specific computational tools have driven the development of novel approaches to their identification and functional characterization. CircRNAs are stable, developmentally regulated, and show tissue- and cell-type-specific expression across different taxonomic groups. They play a crucial role in regulating various biological processes at post-transcriptional and translational levels. However, the involvement of circRNAs in fish immunity has only recently been recognized. There is also broad evidence in mammals that the timely expression of circRNAs in muscle plays an essential role in growth regulation but our understanding of their expression and function in teleosts is still very limited. Here, we discuss the available knowledge about circRNAs and their role in growth and immunity in vertebrates from a comparative perspective, with emphasis on cultured teleost fish. We expect that the interest in teleost circRNAs will increase substantially soon, and we propose that they may be used as biomarkers for selective breeding of farmed fish, thus contributing to the sustainability of the aquaculture sector.

scholarly journals Tissue-Restricted Expression of the Cardiac α-Myosin Heavy Chain Gene Is Controlled by a Downstream Repressor Element Containing a Palindrome of Two Ets-Binding Sites

1998 ◽  
Vol 18 (12) ◽  
pp. 7243-7258 ◽  
Author(s):  
Madhu Gupta ◽  
Radovan Zak ◽  
Towia A. Libermann ◽  
Mahesh P. Gupta
Keyword(s):  
Gene Regulation ◽  
Myosin Heavy Chain ◽  
Cardiac Myocytes ◽  
Heavy Chain ◽  
Binding Sites ◽  
Cardiac Myocyte ◽  
Specific Expression ◽  
Tissue Specific Expression ◽  
Nonmuscle Cells ◽  
Muscle Gene

ABSTRACT The expression of the α-myosin heavy chain (MHC) gene is restricted primarily to cardiac myocytes. To date, several positive regulatory elements and their binding factors involved in α-MHC gene regulation have been identified; however, the mechanism restricting the expression of this gene to cardiac myocytes has yet to be elucidated. In this study, we have identified by using sequential deletion mutants of the rat cardiac α-MHC gene a 30-bp purine-rich negative regulatory (PNR) element located in the first intronic region that appeared to be essential for the tissue-specific expression of the α-MHC gene. Removal of this element alone elevated (20- to 30-fold) the expression of the α-MHC gene in cardiac myocyte cultures and in heart muscle directly injected with plasmid DNA. Surprisingly, this deletion also allowed a significant expression of the α-MHC gene in HeLa and other nonmuscle cells, where it is normally inactive. The PNR element required upstream sequences of the α-MHC gene for negative gene regulation. By DNase I footprint analysis of the PNR element, a palindrome of two high-affinity Ets-binding sites (CTTCCCTGGAAG) was identified. Furthermore, by analyses of site-specific base-pair mutation, mobility gel shift competition, and UV cross-linking, two different Ets-like proteins from cardiac and HeLa cell nuclear extracts were found to bind to the PNR motif. Moreover, the activity of the PNR-binding factor was found to be increased two- to threefold in adult rat hearts subjected to pressure overload hypertrophy, where the α-MHC gene is usually suppressed. These data demonstrate that the PNR element plays a dual role, both downregulating the expression of the α-MHC gene in cardiac myocytes and silencing the muscle gene activity in nonmuscle cells. Similar palindromic Ets-binding motifs are found conserved in the α-MHC genes from different species and in other cardiac myocyte-restricted genes. These results are the first to reveal a role of the Ets class of proteins in controlling the tissue-specific expression of a cardiac muscle gene.

Stage-specific expression of a developmentally regulated gene in Dirofilaria immitis

1992 ◽  
Vol 66 (1) ◽  
pp. 62-67 ◽  
Author(s):  
S. Sun ◽  
T. Matsuura ◽  
K. Sugane
Keyword(s):  
Gene Expression ◽  
Cdna Clone ◽  
Dirofilaria Immitis ◽  
Mrna Level ◽  
Specific Antigen ◽  
Specific Gene ◽  
Developmentally Regulated ◽  
Specific Expression ◽  
Specific Gene Expression

ABSTRACTA previously reported cDNA clone encoding 34 kDa antigenic polypeptide of Dirofilaria immitis (λ cD34) was studied to elucidate the mechanism of stage-specific gene expression. The 34 kDa polypeptide was a larva-specific antigen and the mRNA was detectable in microfilariae but not in adult worms and eggs. The λ cD34 gene was not sex linked and was contained in the genome of D. immitis at each stage. The stage-specific expression of the developmentally regulated gene in D. immitis may be controlled primarily at the mRNA level.

scholarly journals Apoptotic Fragmentation of Tricellulin

2019 ◽  
Vol 20 (19) ◽  
pp. 4882 ◽  
Author(s):  
Susanne Janke ◽  
Sonnhild Mittag ◽  
Juliane Reiche ◽  
Otmar Huber
Keyword(s):  
Coiled Coil ◽  
Apoptotic Cells ◽  
Cleavage Sites ◽  
Central Importance ◽  
Specific Expression ◽  
Caspase Cleavage ◽  
Epithelial Homeostasis ◽  
Cell Layers ◽  
Specific Localization ◽  
Terminal Amino

Apoptotic extrusion of cells from epithelial cell layers is of central importance for epithelial homeostasis. As a prerequisite cell–cell contacts between apoptotic cells and their neighbors have to be dissociated. Tricellular tight junctions (tTJs) represent specialized structures that seal polarized epithelial cells at sites where three cells meet and are characterized by the specific expression of tricellulin and angulins. Here, we specifically addressed the fate of tricellulin in apoptotic cells. Methods: Apoptosis was induced by staurosporine or camptothecin in MDCKII and RT-112 cells. The fate of tricellulin was analyzed by Western blotting and immunofluorescence microscopy. Caspase activity was inhibited by Z-VAD-FMK or Z-DEVD-FMK. Results: Induction of apoptosis induces the degradation of tricellulin with time. Aspartate residues 487 and 441 were identified as caspase cleavage-sites in the C-terminal coiled-coil domain of human tricellulin. Fragmentation of tricellulin was inhibited in the presence of caspase inhibitors or when Asp487 or Asp441 were mutated to asparagine. Deletion of the tricellulin C-terminal amino acids prevented binding to lipolysis-stimulated lipoprotein receptor (LSR)/angulin-1 and thus should impair specific localization of tricellulin to tTJs. Conclusions: Tricellulin is a substrate of caspases and its cleavage in consequence contributes to the dissolution of tTJs during apoptosis.

Multimerization and tubulin binding are required for the SPIRAL2 protein to localize to and stabilize microtubule minus ends

2021 ◽  
Author(s):  
YUANWEI FAN ◽  
Natasha Bilkey ◽  
Ram Dixit
Keyword(s):  
Coiled Coil ◽  
Spatial Arrangement ◽  
In Planta ◽  
Structural Determinants ◽  
Coiled Coil Domain ◽  
Tubulin Binding ◽  
And Function ◽  
Necessary And Sufficient ◽  
Basic Region

Accruing evidence points to the control of microtubule minus-end dynamics as being crucial for the spatial arrangement and function of the microtubule cytoskeleton. In plants, the SPIRAL2 (SPR2) protein has emerged as a microtubule minus-end regulator that is structurally distinct from the animal minus-end regulators. Previously, SPR2 was shown to autonomously localize to microtubule minus ends and decrease their depolymerization rate. Here, we used in vitro and in planta experiments to identify the structural determinants required for SPR2 to recognize and stabilize microtubule minus ends. We show that SPR2 contains a single N-terminal TOG domain that binds to soluble tubulin. The TOG domain, a basic region, and coiled-coil domain are necessary and sufficient to target and stabilize microtubule minus ends. We demonstrate that the coiled-coil domain mediates multimerization of SPR2 that provides avidity for microtubule binding and is essential for binding to soluble tubulin. While TOG domain-containing proteins are traditionally thought to function as microtubule plus-end regulators, our results reveal that nature has repurposed the TOG domain of SPR2 to regulate microtubule minus ends.

GATA factor activity is required for the trophoblast-specific transcriptional regulation of the mouse placental lactogen I gene

Development ◽  
1994 ◽  
Vol 120 (11) ◽  
pp. 3257-3266 ◽  
Author(s):  
Y.K. Ng ◽  
K.M. George ◽  
J.D. Engel ◽  
D.I. Linzer
Keyword(s):  
Gene Promoter ◽  
Placental Lactogen ◽  
Specific Gene ◽  
Gata Factor ◽  
Specific Expression ◽  
Gata Factors ◽  
Transcriptional Regulatory ◽  
Molecular Determinants ◽  
I Gene

The molecular determinants governing tissue-specific gene expression in the placenta are at present only poorly defined, particularly with respect to the regulation of specific hormone genes whose products are vital to embryonic development and the maintenance of a nurturing maternal environment. In continuing our analysis of the trophoblast-specific expression of the mouse placental lactogen I gene, we now demonstrate that the transcription factors GATA-2 and GATA-3 regulate the activity of this gene promoter. These factors are expressed in placental trophoblast cells, with peak levels of the GATA-2, GATA-3 and placental lactogen I mRNAs each accumulating at midgestation. Analysis of a region of the placental lactogen I gene promoter, previously shown to be sufficient for directing trophoblast-specific transcription, revealed the presence of three consensus binding sites for GATA-2 or GATA-3. Both GATA-2 and GATA-3 bind to these sites in vitro and mutation of these sites results in a significant decrease in promoter activity as assayed by transient transfection into the choriocarcinoma-derived cell line Rcho-1, which expresses endogenous GATA-2 and GATA-3. Furthermore, overexpression of GATA factors in Rcho-1 cells stimulates transcription from a co-transfected placental lactogen I gene promoter. Most significantly, expression of GATA-2 or GATA-3 was found to induce transcription from this promoter in transfected non-trophoblast (fibroblast) cells. These data indicate that GATA factors are both limiting and required transcriptional regulatory molecules in placental trophoblasts, and that the tissue specificity of the placental lactogen I gene is determined, at least in part, by GATA-2 and/or GATA-3.

scholarly journals Developmentally regulated and non-sex-specific expression of autosomal dmrt genes in embryos of the Medaka fish (Oryzias latipes)

2004 ◽  
Vol 121 (7-8) ◽  
pp. 997-1005 ◽  
Author(s):  
Christoph Winkler ◽  
Ute Hornung ◽  
Mariko Kondo ◽  
Cordula Neuner ◽  
Jutta Duschl ◽  
...  
Keyword(s):  
Oryzias Latipes ◽  
Medaka Fish ◽  
Developmentally Regulated ◽  
Specific Expression

The mouse Na+-K+-ATPase γ-subunit gene (Fxyd2) encodes three developmentally regulated transcripts

2001 ◽  
Vol 6 (3) ◽  
pp. 129-135 ◽  
Author(s):  
D. HOLSTEAD JONES ◽  
MICHAEL C. GOLDING ◽  
KEVIN J. BARR ◽  
GUO-HUA FONG ◽  
GERALD M. KIDDER
Keyword(s):  
Expression Patterns ◽  
Subunit Gene ◽  
Differential Splicing ◽  
Cloning And Sequencing ◽  
Developmentally Regulated ◽  
Specific Expression ◽  
Catalytic Function ◽  
Γ Subunit ◽  
Alternate Promoter ◽  
Promoter Usage

The Na+-K+-ATPase is understood to function as a hetero-oligomer of α- and β-subunits, but a third subunit, γ, has been proposed to influence the enzyme’s catalytic function. Recently, two variants of the γ-subunit have been described in kidney, raising the possibility of multiple γ-subunits with diverse functions. We now report the cloning and sequencing of the mouse γ-subunit gene ( Fxyd2). Analysis of the structure of the gene shows that it encodes three mRNAs that have distinct NH2-terminal (extracellular) encoding sequences but common transmembrane and COOH-terminal-encoding sequences resulting from differential splicing and, probably, alternate promoter usage. The three mRNAs have tissue-specific expression patterns. The existence of three different extracellular domains of the γ-variants and how they may interact with the sodium pump to alter its cation transport properties must now be taken into account for future understanding of the modulation of the Na+-K+-ATPase by its γ-subunit.

Sign in / Sign up

Export Citation Format

Share Document