Differential regulation of the levels of three gap junction mRNAs in Xenopus embryos.

Xenopus mRNAs that potentially encode gap junction proteins in the oocyte and early embryo have been identified by low-stringency screening of cDNA libraries with cloned mammalian gap junction cDNAs. The levels of these mRNAs show strikingly different temporal regulation and tissue distribution. Using a nomenclature designed to stress important structural similarities of distinct gap junction gene products, the deduced polypeptides have been designated the Xenopus alpha 1 and alpha 2 gap junction proteins. The alpha 2 gap junction mRNA is a maternal transcript that disappears by the late gastrula stage. It is not detected in any organ of the adult except the ovary, and resides primarily, if not exclusively, in the oocytes and early embryos. The alpha 1 gap junction mRNA appears during organogenesis, and is detected in RNA from a wide variety of organs. It is also found in full-grown oocytes, but is rapidly degraded upon oocyte maturation, both in vivo and in vitro. The alpha 1 and alpha 2 mRNAs encode proteins with different degrees of amino acid sequence similarity to the predominant gap junction subunit of the mammalian heart (connexin 43). Together with our earlier report of a mid-embryonic (beta 1) gap junction mRNA, the results suggest that intercellular communication during oocyte growth and postfertilization development is a complex phenomenon involving the coordinated regulation of several genes.

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Photoperiod-Dependent Effects of 4-tert-Octylphenol on Adherens and Gap Junction Proteins in Bank Vole Seminiferous Tubules

International Journal of Endocrinology ◽

10.1155/2013/134589 ◽

2013 ◽

Vol 2013 ◽

pp. 1-11 ◽

Cited By ~ 11

Author(s):

Anna Hejmej ◽

Malgorzata Kotula-Balak ◽

Katarzyna Chojnacka ◽

Paulina Kuras ◽

Marta Lydka-Zarzycka ◽

...

Keyword(s):

Estrogen Receptor ◽

Gap Junction ◽

Bank Vole ◽

Connexin 43 ◽

Biological Effects ◽

Seminiferous Tubules ◽

Long Term Treatment ◽

Gap Junction Proteins ◽

Junction Proteins

In the present study we evaluatedin vivoandin vitroeffects of 4-tert-octylphenol (OP) on the expression and distribution of adherens and gap junction proteins, N-cadherin,β-catenin, and connexin 43 (Cx43), in testes of seasonally breeding rodents, bank voles. We found that in bank vole testes expression and distribution of N-cadherin,β-catenin, and Cx43 were photoperiod dependent. Long-term treatment with OP (200 mg/kg b.w.) resulted in the reduction of junction proteins expressions (P<0.05,P<0.01) and their delocalization in the testes of males kept in long photoperiod, whereas in short-day animals slight increase of Cx43 (P<0.05), N-cadherin, andβ-catenin (statistically nonsignificant) levels was observed. Effects of OP appeared to be independent of FSH and were maintained duringin vitroorgan culture, indicating that OP acts directly on adherens and gap junction proteins in the testes. An experiment performed using an antiestrogen ICI 182,780 demonstrated that the biological effects of OP onβ-catenin and Cx43 involve an estrogen receptor-mediated response. Taken together, in bank vole organization of adherens and gap junctions and their susceptibility to OP are related to the length of photoperiod. Alterations in cadherin/catenin and Cx43-based junction may partially result from activation of estrogen receptorαand/orβsignaling pathway.

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A COUP-TF/Svp homolog is highly expressed during vitellogenesis in the mosquito Aedes aegypti

Journal of Molecular Endocrinology ◽

10.1677/jme.0.0290223 ◽

2002 ◽

Vol 29 (2) ◽

pp. 223-238 ◽

Cited By ~ 22

Author(s):

K Miura ◽

J Zhu ◽

NT Dittmer ◽

L Chen ◽

AS Raikhel

Keyword(s):

Aedes Aegypti ◽

Blood Meal ◽

Fat Body ◽

Sequence Similarity ◽

Amino Acid Sequence Similarity ◽

Receptor Complex ◽

Ecdysone Receptor ◽

Ecdysteroid Receptor

In the mosquito Aedes aegypti, vitellogenesis is activated via an ecdysteroid hormonal cascade initiated by a blood meal. The functional ecdysone receptor is a heterodimer composed of the ecdysone receptor (EcR) and ultraspiracle, the homolog of the retinoid X receptor. The precise tuning of this hormonal response requires participation of both positive and negative transcriptional regulators. In Drosophila, Svp, a homolog of chicken ovalbumin upstream promoter transcription factor (COUP-TF), inhibits ecdysone receptor complex-mediated transactivation in vitro and in vivo. Here we report the cloning and characterization of the Svp homolog in mosquito Aedes aegypti, AaSvp. It possesses a high degree of amino acid sequence similarity to the members of the COUP-TF/Svp subfamily. AaSvp transcripts and protein are present in the fat body at high levels from the state of arrest to about 60 h post blood meal. AaSvp binds strongly to a variety of direct repeats of the sequence AGGTCA, but weakly to inverted repeats such as hsp27 EcRE. Transient transfection assays in Drosophila S2 cells showed that AaSvp was able to repress 20-hydroxyecdysone (20E)-dependent transactivation mediated by the mosquito ecdysteroid receptor complex. These data suggest that AaSvp negatively regulates the 20E signaling in the fat body during mosquito vitellogenesis.

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The Bacterial Actin-Like Cytoskeleton

Microbiology and Molecular Biology Reviews ◽

10.1128/mmbr.00014-06 ◽

2006 ◽

Vol 70 (4) ◽

pp. 888-909 ◽

Cited By ~ 132

Author(s):

Rut Carballido-López

Keyword(s):

Sequence Similarity ◽

Amino Acid Sequence Similarity ◽

Bacterial Cells ◽

Cell Morphogenesis ◽

Cellular Processes ◽

Macromolecular Trafficking ◽

Nucleoprotein Complexes ◽

Dna Partitioning

SUMMARY Recent advances have shown conclusively that bacterial cells possess distant but true homologues of actin (MreB, ParM, and the recently uncovered MamK protein). Despite weak amino acid sequence similarity, MreB and ParM exhibit high structural homology to actin. Just like F-actin in eukaryotes, MreB and ParM assemble into highly dynamic filamentous structures in vivo and in vitro. MreB-like proteins are essential for cell viability and have been implicated in major cellular processes, including cell morphogenesis, chromosome segregation, and cell polarity. ParM (a plasmid-encoded actin homologue) is responsible for driving plasmid-DNA partitioning. The dynamic prokaryotic actin-like cytoskeleton is thought to serve as a central organizer for the targeting and accurate positioning of proteins and nucleoprotein complexes, thereby (and by analogy to the eukaryotic cytoskeleton) spatially and temporally controlling macromolecular trafficking in bacterial cells. In this paper, the general properties and known functions of the actin orthologues in bacteria are reviewed.

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Unilateral Effects of Pregnancy on Differential Expression of the Gap Junction Proteins Connexin 43 and 37 in Ovine Uterine Artery Endothelium.

Biology of Reproduction ◽

10.1093/biolreprod/83.s1.477 ◽

2010 ◽

Vol 83 (Suppl_1) ◽

pp. 477-477

Author(s):

Timothy J. Morschauser ◽

Jayanth Ramadoss ◽

Jill M. Koch ◽

Gladys E. Lopez ◽

Ian M. Bird ◽

...

Keyword(s):

Gap Junction ◽

Differential Expression ◽

Connexin 43 ◽

Uterine Artery ◽

Unilateral Effects ◽

Gap Junction Proteins ◽

Junction Proteins

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Sympathetic Overactivity in CKD Disrupts Buffering of Neurotransmission by Endothelium-Derived Hyperpolarizing Factor and Enhances Vasoconstriction

Journal of the American Society of Nephrology ◽

10.1681/asn.2020030234 ◽

2020 ◽

Vol 31 (10) ◽

pp. 2312-2325

Author(s):

Wei Cao ◽

Liling Wu ◽

Xiaodong Zhang ◽

Jing Zhou ◽

Jian Wang ◽

...

Keyword(s):

Gap Junction ◽

Vascular Resistance ◽

Connexin 43 ◽

Structural Changes ◽

Ex Vivo ◽

Resistance Arteries ◽

Cx43 Expression ◽

Neurovascular Transmission

BackgroundHypertension commonly complicates CKD. Vascular smooth muscle cells (VSMCs) of resistance arteries receive signals from the sympathetic nervous system that induce an endothelial cell (EC)–dependent anticontractile response that moderates vasoconstriction. However, the specific role of this pathway in the enhanced vasoconstriction in CKD is unknown.MethodsA mouse model of CKD hypertension generated with 5/6-nephrectomy (5/6Nx) was used to investigate the hypothesis that an impaired anticontractile mechanism enhances sympathetic vasoconstriction. In vivo, ex vivo (isolated mesenteric resistance arteries), and in vitro (VSMC and EC coculture) models demonstrated neurovascular transmission and its contribution to vascular resistance.ResultsBy 4 weeks, 5/6Nx mice (versus sham) had augmented increases in mesenteric vascular resistance and mean arterial pressure with carotid artery occlusion, accompanied by decreased connexin 43 (Cx43) expression at myoendothelial junctions (MEJs), impaired gap junction function, decreased EC-dependent hyperpolarization (EDH), and enhanced contractions. Exposure of VSMCs to NE for 24 hours in a vascular cell coculture decreased MEJ Cx43 expression and MEJ gap junction function. These changes preceded vascular structural changes evident only at week 8. Inhibition of central sympathetic outflow or transfection of Cx43 normalized neurovascular transmission and vasoconstriction in 5/6Nx mice.Conclusions5/6Nx mice have enhanced neurovascular transmission and vasoconstriction from an impaired EDH anticontractile component before vascular structural changes. These neurovascular changes depend on an enhanced sympathetic discharge that impairs the expression of Cx43 in gap junctions at MEJs, thereby interrupting EDH responses that normally moderate vascular tone. Dysregulation of neurovascular transmission may contribute to the development of hypertension in CKD.

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Differential Regulation of Gap Junction Proteins Connexin 40 and Connexin 43 in Cardiomyocytes

International Journal of Pharmacology ◽

10.3923/ijp.2005.44.54 ◽

2004 ◽

Vol 1 (1) ◽

pp. 44-54 ◽

Cited By ~ 3

Author(s):

A. Salameh ◽

K. Muhlberg . ◽

P. Schneider . ◽

S. Dhein . ◽

D. Pfeiffer .

Keyword(s):

Gap Junction ◽

Connexin 43 ◽

Differential Regulation ◽

Connexin 40 ◽

Gap Junction Proteins ◽

Junction Proteins

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Connexin 43 gap junction proteins are up-regulated in remyelinating spinal cord

Journal of Neuroscience Research ◽

10.1002/jnr.21194 ◽

2007 ◽

Vol 85 (5) ◽

pp. 945-953 ◽

Cited By ~ 22

Author(s):

W.A. Roscoe ◽

E. Messersmith ◽

A. Meyer-Franke ◽

B. Wipke ◽

S.J. Karlik

Keyword(s):

Spinal Cord ◽

Gap Junction ◽

Connexin 43 ◽

Gap Junction Proteins ◽

Junction Proteins

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Toll-Like Receptor-Mediated Cardiac Injury during Experimental Sepsis

Mediators of Inflammation ◽

10.1155/2020/6051983 ◽

2020 ◽

Vol 2020 ◽

pp. 1-12

Author(s):

Ina Lackner ◽

Birte Weber ◽

Shinjini Chakraborty ◽

Sonja Braumüller ◽

Markus Huber-Lang ◽

...

Keyword(s):

Gap Junction ◽

Mrna Expression ◽

Troponin I ◽

Receptor Subtype ◽

Septic Cardiomyopathy ◽

Cardiac Structure ◽

Human Cardiomyocytes ◽

Gap Junction Proteins ◽

Junction Proteins

Sepsis is associated with global cardiac dysfunction and with high mortality rate. The development of septic cardiomyopathy is due to complex interactions of damage-associated molecular patters, cytokines, and complement activation products. The aim of this study was to define the effects of sepsis on cardiac structure, gap junction, and tight junction (TJ) proteins. Sepsis was induced by cecal ligation and puncture in male C57BL/6 mice. After a period of 24 h, the expression of cardiac structure, gap junction, and TJ proteins was determined. Murine HL-1 cells were stimulated with LPS, and mRNA expression of cardiac structure and gap junction proteins, intracellular reactive oxygen species, and troponin I release was analyzed. Furthermore, pyrogenic receptor subtype 7 (P2X7) expression and troponin I release of human cardiomyocytes (iPS) were determined after LPS exposure. In vivo, protein expression of connexin43 and α-actinin was decreased after the onset of polymicrobial sepsis, whereas in HL-1 cells, mRNA expression of connexin43, α-actinin, and desmin was increased in the presence of LPS. Expression of TJ proteins was not affected in vivo during sepsis. Although the presence of LPS and nigericin resulted in a significant troponin I release from HL-1 cells. Sepsis affected cardiac structure and gap junction proteins in mice, potentially contributing to compromised cardiac function.

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Characterization of the novel OXA-213-like β-lactamase OXA-822 from Acinetobacter calcoaceticus

Journal of Antimicrobial Chemotherapy ◽

10.1093/jac/dkaa488 ◽

2020 ◽

Author(s):

Manuela Tietgen ◽

Laura Leukert ◽

Julian Sommer ◽

Jan S Kramer ◽

Steffen Brunst ◽

...

Keyword(s):

Galleria Mellonella ◽

Sequence Similarity ◽

Acinetobacter Calcoaceticus ◽

Amino Acid Sequence Similarity ◽

Control Group ◽

Infection Model ◽

The Novel ◽

High Turnover

Abstract Objectives This study analysed the novel carbapenem-hydrolysing class D β-lactamase OXA-822 identified in the clinical Acinetobacter calcoaceticus isolate AC_2117. Methods WGS was employed for identification of β-lactamases. Micro-broth dilution was used for evaluation of antibiotic susceptibility of AC_2117 and transformants containing blaOXA-822. After heterologous purification of OXA-822, OXA-359 and OXA-213, enzyme kinetics were determined using spectrometry. The effect of OXA-822 upon meropenem treatment was analysed in the Galleria mellonella in vivo infection model. Results OXA-822 is a member of the intrinsic OXA-213-like family found in A. calcoaceticus and Acinetobacter pittii. Amino acid sequence similarity to the nearest related OXA-359 was 97%. Production of OXA-822, OXA-359 and OXA-213 in Acinetobacter baumannii ATCC® 19606T resulted in elevated MICs for carbapenems (up to 16-fold). Penicillinase activity of the purified OXA-822 revealed high KM values, in the millimolar range, combined with high turnover numbers. OXA-822 showed the highest affinity to carbapenems, but affinity to imipenem was ∼10-fold lower compared with other carbapenems. Molecular modelling revealed that imipenem does not interact with a negatively charged side chain of OXA-822, as doripenem does, leading to the lower affinity. Presence of OXA-822 decreased survival of infected Galleria mellonella larvae after treatment with meropenem. Only 52.7% ± 7.7% of the larvae survived after 24 h compared with 90.9% ± 3.7% survival in the control group. Conclusions The novel OXA-822 from a clinical A. calcoaceticus isolate displayed penicillinase and carbapenemase activity in vitro, elevated MICs in different species and decreased carbapenem susceptibility in A. baumannii in vivo.

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