scholarly journals Armc8 is an evolutionarily conserved armadillo protein involved in cell–cell adhesion complexes through multiple molecular interactions

2019 ◽  
Vol 39 (8) ◽  
Author(s):  
Ismail Sahin Gul ◽  
Paco Hulpiau ◽  
Ellen Sanders ◽  
Frans van Roy ◽  
Jolanda van Hengel

Abstract Armadillo-repeat-containing protein 8 (Armc8) belongs to the family of armadillo-repeat containing proteins, which have been found to be involved in diverse cellular functions including cell–cell contacts and intracellular signaling. By comparative analyses of armadillo repeat protein structures and genomes from various premetazoan and metazoan species, we identified orthologs of human Armc8 and analyzed in detail the evolutionary relationship of Armc8 genes and their encoded proteins. Armc8 is a highly ancestral armadillo protein although not present in yeast. Consequently, Armc8 is not the human ortholog of yeast Gid5/Vid28. Further, we performed a candidate approach to characterize new protein interactors of Armc8. Interactions between Armc8 and specific δ-catenins (plakophilins-1, -2, -3 and p0071) were observed by the yeast two-hybrid approach and confirmed by co-immunoprecipitation and co-localization. We also showed that Armc8 interacts specifically with αE-catenin but neither with αN-catenin nor with αT-catenin. Degradation of αE-catenin has been reported to be important in cancer and to be regulated by Armc8. A similar process may occur with respect to plakophilins in desmosomes. Deregulation of desmosomal proteins has been considered to contribute to tumorigenesis.

Author(s):  
Pawan Kumar Jayaswal ◽  
Asheesh Shanker ◽  
Nagendra Kumar Singh

Actin and tubulin are cytoskeleton proteins, which are important components of the celland are conserved across species. Despite their crucial significance in cell motility and cell division the distribution and phylogeny of actin and tubulin genes across taxa is poorly understood. Here we used publicly available genomic data of 49 model species of plants, animals, fungi and Protista for further understanding the distribution of these genes among diverse eukaryotic species using rice as reference. The highest numbers of rice actin and tubulin gene homologs were present in plants followed by animals, fungi and Protista species, whereas ten actin and nine tubulin genes were conserved in all 49 species. Phylogenetic analysis of 19 actin and 18 tubulin genes clustered them into four major groups each. One each of the actin and tubulin gene clusters was conserved across eukaryotic species. Species trees based on the conserved actin and tubulin genes showed evolutionary relationship of 49 different taxa clustered into plants, animals, fungi and Protista. This study provides a phylogenetic insight into the evolution of actin and tubulin genes in diverse eukaryotic species.


1998 ◽  
Vol 275 (2) ◽  
pp. L203-L222 ◽  
Author(s):  
Timothy M. Moore ◽  
Paul M. Chetham ◽  
John J. Kelly ◽  
Troy Stevens

Pulmonary endothelium forms a semiselective barrier that regulates fluid balance and leukocyte trafficking. During the course of lung inflammation, neurohumoral mediators and oxidants act on endothelial cells to induce intercellular gaps permissive for transudation of proteinaceous fluid from blood into the interstitium. Intracellular signals activated by neurohumoral mediators and oxidants that evoke intercellular gap formation are incompletely understood. Cytosolic Ca2+ concentration ([Ca2+]i) and cAMP are two signals that importantly dictate cell-cell apposition. Although increased [Ca2+]ipromotes disruption of the macrovascular endothelial cell barrier, increased cAMP enhances endothelial barrier function. Furthermore, during the course of inflammation, elevated endothelial cell [Ca2+]idecreases cAMP to facilitate intercellular gap formation. Given the significance of both [Ca2+]iand cAMP in mediating cell-cell apposition, this review addresses potential sites of cross talk between these two intracellular signaling pathways. Emerging data also indicate that endothelial cells derived from different vascular sites within the pulmonary circulation exhibit distinct sensitivities to permeability-inducing stimuli; that is, elevated [Ca2+]ipromotes macrovascular but not microvascular barrier disruption. Thus this review also considers the roles of [Ca2+]iand cAMP in mediating site-specific alterations in endothelial permeability.


Author(s):  
Lehai Zhang ◽  
Shifu Wang ◽  
Qian Ren ◽  
Junjie Yang ◽  
Yanqin Lu ◽  
...  

AbstractIn the epidemic evolution of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the issues of mutation, origin, typing and the effect of mutation on molecular detection remain to be unrevealed. In order to identify the evolutionary relationship of SARS-CoV-2 and evaluate the detection efficiency of primers that are currently used in different countries, we retrieved genomic sequences of 373 SARS-CoV-2 strains from multiple databases and performed genome-wide variation analysis. According to the nucleotide C28144T variation, the SARS-CoV-2 can be divided into group A (117 strains) and group B (256 strains). The spike protein gene (S gene) coding region 1841 (total 23403) A1841G, formed a B1 subgroup (40 strains) in group B, of which 30 strains were from European and American countries in March (especially Washington, USA). These mutations are likely to be influenced by the environment or the immunization selection pressure of different populations. Although the mutation is not in the receptor binding region (RBD) and alkaline cleavage region, it may also affect the ability of transmission and pathogenicity; however, the significance is not yet clear. As the ratio of A / B strains in the epidemic months showed an increasing trend (0.35: 1 in January, 0.62: 1 in February and 0.76: 1 in March), it seems that the transmissibility of group A strains becomes stronger with time. Based on the variation of 11 nucleotide sites during the epidemic process, it is speculated that the Washington strain is more like an ancestor type, and the Wuhan strain is the offspring of the group A virus strain. By comparing the detection capabilities of primers in different countries, the SARS-CoV-2 nucleotide variation may only affect molecular detection of very few strains. The differences in the transmissibility, pathogenicity and clinical manifestations of different types of strains require further investigations.


1996 ◽  
Vol 132 (1) ◽  
pp. 181-193 ◽  
Author(s):  
S Yoshida ◽  
A Fujisawa-Sehara ◽  
T Taki ◽  
K Arai ◽  
Y Nabeshima

Myogenic cells provide excellent in vitro models for studying the cell growth and differentiation. In this study we report that lysophosphatidic acid (LPA), a bioactive phospholipid contained in serum, stimulates the growth and inhibits the differentiation of mouse C2C12 myoblast cells, in a distinct manner from basic fibroblast growth factor (bFGF) whose mitotic and anti-differentiation actions have been well investigated. These actions of LPA were both blocked by pertussis toxin, suggesting the involvement of Gi class of G proteins, whereas bFGF acts through receptor tyrosine kinases. Detailed analysis revealed that LPA and bFGF act differently in regulating the myogenic basic helix-loop-helix (bHLH) proteins, the key players in myogenic differentiation process. LPA stimulates the proliferation of undifferentiated myoblasts allowing the continued expression of MyoD, but in contrast, bFGF does so with the MyoD expression suppressed at the mRNA level. Both compounds maintain the myf-5 expression, and suppress the myogenin expression. In addition, while LPA did not inhibit cell-cell contact-induced differentiation, bFGF strongly inhibited this process. Furthermore, LPA and bFGF act cooperatively in their mitogenic and anti-differentiation abilities. These findings indicate that LPA and bFGF differently stimulate intracellular signaling pathways, resulting in proliferating myoblasts each bearing a distinct expression pattern of myogenic bHLH proteins and distinct differentiation potentials in response to cell-cell contact, and illustrate the biological significance of Gi-mediated and tyrosine kinase-mediated signals.


2004 ◽  
Vol 19 (1) ◽  
pp. 106-116 ◽  
Author(s):  
Damian G. Romero ◽  
Maria Plonczynski ◽  
Gaston R. Vergara ◽  
Elise P. Gomez-Sanchez ◽  
Celso E. Gomez-Sanchez

Evidence for the dysregulation of aldosterone synthesis in cardiovascular pathophysiology has renewed interest in the control of its production. Cellular mechanisms by which angiotensin II (ANG II) stimulates aldosterone synthesis in the adrenal zona glomerulosa are incompletely understood. To elucidate the mechanism of intracellular signaling by ANG II stimulation in the adrenal, we have studied immediate-early regulated genes in human adrenal H295R cells using cDNA microarrays. H295R cells were stimulated with ANG II for 3 h. Gene expression was analyzed by microarray technology and validated by real-time RT-PCR. Eleven genes were found to be upregulated by ANG II. These encode the proteins for ferredoxin, Nor1, Nurr1, c6orf37, CAT-1, A20, MBLL, M-Ras, RhoB, GADD45α, and a novel protein designated FLJ45273 . Maximum expression levels for all genes occurred 3–6 h after ANG II stimulation. This increase was dose dependent and preceded maximal aldosterone production. Other aldosterone secretagogues, K+and endothelin-1 (ET-1), also induced the expression of these genes with variable efficiency depending on the gene and with lower potency than ANG II. ACTH had negligible effect on gene expression except for the CAT-1 and Nurr1 genes. These ANG II-stimulated genes are involved in several cellular functions and are good candidate effectors and regulators of ANG II-mediated effects in adrenal zona glomerulosa.


Author(s):  
Haniyeh Gaffari-Nazari ◽  
Samira Karami ◽  
Leila Noorazar ◽  
Sayeh Parkhideh ◽  
Elham Roshandel ◽  
...  

Background: The PI3K/Akt/mTOR signaling pathway is one of the most important intracellular signaling pathways by regulating the cell cycle process. The direct relationship of this pathway with important mechanisms such as cell quiescence, longevity, and proliferation has been established. The overactive PI3K pathway with decreased and increased apoptosis and cell proliferation respectively is involved in pathogenesis of many cancers, including blood malignancies such as leukemia. Methods: Laboratory findings have shown that different factors, such as miRNAs, play a role in regulating PI3K signaling pathway. These molecules can alter the fate of a cell by interfering in suppression/overexpression of mRNA, transcription factors or stimulating the transcription of some genes. In this article, we reviewed the role of miRNAs in regulating the PI3K/Akt/mTOR pathway and its effect on leukemic progression and treatment failure. Conclusion: At present, miRNAs are known to be one of the causes of treatment failure and relapse in cancers.


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