1,046 research outputs found
Homeoprotein Hbx4 represses adhesion molecule governing cytokinesis and development
No full textHomeobox genes encode proteins with a highly conserved DNA-binding motif and provoke morphological diversification of body segments by differentially controlling the expression of downstream targets. Here, we have identified _hbx4_, one of many homeobox genes in _Dictyostelium discoideum_ and investigated its role during growth and development. In suspension, Hbx4-overexpressing cells, Hbx4^OE^, showed defects in cytokinesis and growth rate. During development, Hbx4^OE^ and _hbx4_-disrupting cells, _hbx4¯_ made differences in shape of mound and slug, cell-type proportioning from wild type KAx3 cells. These phenotypes were similar to those of mutant defective in _cadA_ encoding Ca^2+^-dependent cell adhesion molecule so that we investigated the relationship between _hbx4_ and _cadA_. Overexpression of Hbx4 inhibited the expression of _cadA_ and cAMP also failed to stimulate _cadA_ in Hbx4^OE^. Furthermore, gel mobility shift assay showed the promoter of _cadA_ contained Hbx4-binding site, indicating Hbx4 negatively regulates the expression of _cadA_. Proteome analysis revealed that overexpression of Hbx4 repressed the _rdiA_ and _abpB_ encoding rho guanine nucleotide dissociation inhibitor1, RhoGDI1 and actin bundling protein 34, ABP34, respectively. And the overexpression of _cadA_ in Hbx4^OE^ cells rescued the defects and increased mRNA level of _rdiA_, _abpB_ and one of Rho GTPase, _rac1b_. These results suggested that Hbx4 can modulate cytokinesis, cell sorting and cell-type proportioning by repressing _cadA_ that regulates GTPase-dependent signaling pathway
Rho GTPase signalling in cell migration
No full textCells migrate in multiple different ways depending on their environment, which includes the extracellular matrix composition, interactions with other cells, and chemical stimuli. For all types of cell migration, Rho GTPases play a central role, although the relative contribution of each Rho GTPase depends on the environment and cell type. Here, I review recent advances in our understanding of how Rho GTPases contribute to different types of migration, comparing lamellipodium-driven versus bleb-driven migration modes. I also describe how cells migrate across the endothelium. In addition to Rho, Rac and Cdc42, which are well known to regulate migration, I discuss the roles of other less-well characterized members of the Rho family
AMPylation of Rho GTPases Subverts Multiple Host Signaling Processes
No full textabstract: Rho GTPases are frequent targets of virulence factors as they are keystone signaling molecules. Herein, we demonstrate that AMPylation of Rho GTPases by VopS is a multifaceted virulence mechanism that counters several host immunity strategies. Activation of NFκB, Erk, and JNK kinase signaling pathways were inhibited in a VopS-dependent manner during infection with Vibrio parahaemolyticus. Phosphorylation and degradation of IKBα were inhibited in the presence of VopS as was nuclear translocation of the NFκB subunit p65. AMPylation also prevented the generation of superoxide by the phagocytic NADPH oxidase complex, potentially by inhibiting the interaction of Rac and p67. Furthermore, the interaction of GTPases with the E3 ubiquitin ligases cIAP1 and XIAP was hindered, leading to decreased degradation of Rac and RhoA during infection. Finally, we screened for novel Rac1 interactions using a nucleic acid programmable protein array and discovered that Rac1 binds to the protein C1QA, a protein known to promote immune signaling in the cytosol. Interestingly, this interaction was disrupted by AMPylation. We conclude that AMPylation of Rho Family GTPases by VopS results in diverse inhibitory consequences during infection beyond the most obvious phenotype, the collapse of the actin cytoskeleton.This research was originally published in JOURNAL OF BIOLOGICAL CHEMISTRY. Woolery, Andrew R., Yu, Xiaobo, LaBaer, Joshua, & Orth, Kim. [Title]. JOURNAL OF BIOLOGICAL CHEMISTRY. 2014; 289:0-0. © the American Society for Biochemistry and Molecular Biology
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The Small Rho GTPase TC10 Modulates B Cell Immune Responses
No full textRho family GTPases regulate diverse cellular events, such as cell motility, polarity, and vesicle traffic. Although a wealth of data exists on the canonical Rho GTPases RhoA, Rac1, and Cdc42, several other family members remain poorly studied. In B cells, we recently demonstrated a critical role for Cdc42 in plasma cell differentiation. In this study, we focus on a close homolog of Cdc42, TC10 (also known as RhoQ), and investigate its physiological role in B cells. By generating a TC10-deficient mouse model, we show that despite reduced total B cell numbers, B cell development in these mice occurs normally through distinct developmental stages. Upon immunization, IgM levels were reduced and, upon viral infection, germinal center responses were defective in TC10-deficient mice. BCR signaling was mildly affected, whereas cell migration remained normal in TC10-deficient B cells. Furthermore, by generating a TC10/Cdc42 double knockout mouse model, we found that TC10 can compensate for the lack of Cdc42 in TLR-induced cell activation and proliferation, so the two proteins play partly redundant roles. Taken together, by combining in vivo and in vitro analysis using TC10-deficient mice, we define the poorly studied Rho GTPase TC10 as an immunomodulatory molecule playing a role in physiological B cell responses.Version of Recor
RETRACTED: Nuclear Translocation of LIM Kinase Mediates Rho-Rho Kinase Regulation of Cyclin D1 Expression
No full textAbstractThis article has been retracted at the request of the authors.Reason: We have recently reviewed the primary source data for our paper entitled “Nuclear Translocation of LIM Kinase Mediates Rho-Rho Kinase Regulation of Cyclin D1 Expression” [Dev. Cell, 5: 273–284 (2003)]. We have found that portions of the figures assembled by the lead author are not fully supported by the primary data. We are therefore retracting this paper. We express our deep regret to the scientific community
FragGeneScan: Predicting genes in short and error-prone reads
No full textThe advances of next-generation sequencing technology have facilitated metagenomics research that attempts to determine directly the whole collection of genetic material within an environmental sample (i.e. the metagenome). Identification of genes directly from short reads has become an important yet challenging problem in annotating metagenomes, since the assembly of metagenomes is often not available. Gene predictors developed for whole genomes (e.g. Glimmer) and recently developed for metagenomic sequences (e.g. MetaGene) show a significant decrease in performance as the sequencing error rates increase, or as reads get shorter. We have developed a novel gene prediction method FragGeneScan, which combines sequencing error models and codon usages in a hidden Markov model to improve the prediction of protein-coding region in short reads. The performance of FragGeneScan was comparable to Glimmer and MetaGene for complete genomes. But for short reads, FragGeneScan consistently outperformed MetaGene (accuracy improved ���62% for reads of 400 bases with 1% sequencing errors, and ���18% for short reads of 100 bases that are error free). When applied to metagenomes, FragGeneScan recovered substantially more genes than MetaGene predicted (90% of the genes identified by homology search), and many novel genes with no homologs in current protein sequence database. �� The Author(s) 2010.Funding for open access charge: National Institutes of Health (1R01HG004908-02); National Science Foundation (CAREER award DBI-0845685)
Comparison of physicochemical properties of pork from 4 different pig breeds
No full textTitle: Comparison of physicochemical properties of pork from 4 different pig breeds Author(s): Kim, Y. B.; Rho, J. H.; Richardson, I., et al. Source: Journal of Animal Science and Technology Volume: 42 Issue: 2 Pages: 195-202 Published: April, 2000Title: Comparison of physicochemical properties of pork from 4 different pig breeds Author(s): Kim, Y. B.; Rho, J. H.; Richardson, I., et al. Source: Journal of Animal Science and Technology Volume: 42 Issue: 2 Pages: 195-202 Published: April, 200
Dispersive contribution of rho(1450,1700) decays and X(1576)
No full textWe study whether the broad enhancement X(1576) arises from the final state interaction (FSI) of rho(1450,1700) -> rho(+)rho(-) -> K+K- decays. Both the absorptive and dispersive contributions of the above amplitudes are considered since the intermediate states are very close to p(1450,1700). The same mechanism leads to a similar enhancement around 1580 MeV in the pi(+) pi(-) spectrum in the J/psi -> pi(0) pi(+) pi(-) channel, which can be used to test whether X(1576) can be ascribed to the FSI effect of rho(1450,1700) -> rho(+)rho(-).http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000248961100020&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=8e1609b174ce4e31116a60747a720701Physics, MultidisciplinarySCI(E)中国科技核心期刊(ISTIC)中国科学引文数据库(CSCD)13ARTICLE92537-25392
Application of the QCD light cone sum rule to tetraquarks: The strong vertices XbXb rho and XcXc rho
No full textAzizi, Kazem (Dogus Author)The full version of the QCD light-cone sum rule method is applied to tetraquarks containing a single heavy b or c quark. To this end, investigations of the strong vertices XbXb rho and XcXc rho are performed, where X-b = [su][(b) over bar(d) over bar] and X-c = [su][(c) over bar(d) over bar] are the exotic states built of four quarks of different flavors. The strong coupling constants G(XbXb rho) and G(XcXc rho) corresponding to these vertices are found using the rho-meson leading- and higher-twist distribution amplitudes. In the calculations, X-b and X-c are treated as scalar bound states of a diquark and antidiquark
Cellular Tango: How extracellular matrix adhesion choreographs Rac-Rho signaling and cell movement
No full textThe small GTPases Rac and Rho are known to regulate eukaryotic cell shape, promoting front protrusion (Rac) or rear retraction (Rho) of the cell edge. Such cell deformation changes the contact and adhesion of cell to the extracellular matrix (ECM), while ECM signaling through integrin receptors also affects GTPase activity. We develop and investigate a model for this three-way feedback loop in 1D and 2D spatial domains, as well as in a fully deforming 2D cell shapes with detailed adhesion-bond biophysics. The model consists of reaction-diffusion equations solved numerically with open-source software, Morpheus, and with custom-built cellular Potts model simulations. We find a variety of patterns and cell behaviors, including persistent polarity, flipped front-back cell polarity oscillations, spiral waves, and random protrusion-retraction.We show that the observed spatial patterns depend on the cell shape, and vice versa. Mathematical Physic
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