scholarly journals Phosphoinositide 3-Kinase C2β Regulates Cytoskeletal Organization and Cell Migration via Rac-dependent Mechanisms

2006 ◽  
Vol 17 (9) ◽  
pp. 3729-3744 ◽  
Author(s):  
Roy M. Katso ◽  
Olivier E. Pardo ◽  
Andrea Palamidessi ◽  
Clemens M. Franz ◽  
Marin Marinov ◽  
...  
Keyword(s):  
Cell Migration ◽  
Molecular Mechanisms ◽  
Egf Receptor ◽  
Human Tumor ◽  
Class Ii ◽  
Dominant Negative ◽  
Class I ◽  
Membrane Ruffling ◽  
And Migration ◽  
Phosphoinositide 3 Kinase

Receptor-linked class I phosphoinositide 3-kinases (PI3Ks) induce assembly of signal transduction complexes through protein–protein and protein–lipid interactions that mediate cell proliferation, survival, and migration. Although class II PI3Ks have the potential to make the same phosphoinositides as class I PI3Ks, their precise cellular role is currently unclear. In this report, we demonstrate that class II phosphoinositide 3-kinase C2β (PI3KC2β) associates with the Eps8/Abi1/Sos1 complex and is recruited to the EGF receptor as part of a multiprotein signaling complex also involving Shc and Grb2. Increased expression of PI3KC2β stimulated Rac activity in A-431 epidermoid carcinoma cells, resulting in enhanced membrane ruffling and migration speed of the cells. Conversely, expression of dominant negative PI3KC2β reduced Rac activity, membrane ruffling, and cell migration. Moreover, PI3KC2β-overexpressing cells were protected from anoikis and displayed enhanced proliferation, independently of Rac function. Taken together, these findings suggest that PI3KC2β regulates the migration and survival of human tumor cells by distinct molecular mechanisms.

scholarly journals Targeted Expression of the Class II Phosphoinositide 3-Kinase in Drosophila melanogaster Reveals Lipid Kinase-Dependent Effects on Patterning and Interactions with Receptor Signaling Pathways

2004 ◽  
Vol 24 (2) ◽  
pp. 796-808 ◽  
Author(s):  
Lindsay K. MacDougall ◽  
Mary Elizabeth Gagou ◽  
Sally J. Leevers ◽  
Ernst Hafen ◽  
Michael D. Waterfield
Keyword(s):  
Drosophila Melanogaster ◽  
Signaling Pathways ◽  
Egf Receptor ◽  
Adaptor Protein ◽  
Class Ii ◽  
Notch Receptor ◽  
Mitogen Activated Protein Kinase ◽  
Class I ◽  
Wing Venation ◽  
Receptor Signaling

ABSTRACT Phosphoinositide 3-kinases (PI3Ks) can be divided into three distinct classes (I, II, and III) on the basis of their domain structures and the lipid signals that they generate. Functions have been assigned to the class I and class III enzymes but have not been established for the class II PI3Ks. We have obtained the first evidence for a biological function for a class II PI3K by expressing this enzyme during Drosophila melanogaster development and by using deficiencies that remove the endogenous gene. Wild-type and catalytically inactive PI3K_68D transgenes have opposite effects on the number of sensory bristles and on wing venation phenotypes induced by modified epidermal growth factor (EGF) receptor signaling. These results indicate that the endogenous PI3K_68D may act antagonistically to the EGF receptor-stimulated Ras-mitogen-activated protein kinase pathway and downstream of, or parallel to, the Notch receptor. A class II polyproline motif in PI3K_68D can bind the Drk adaptor protein in vitro, primarily via the N-terminal SH3 domain of Drk. Drk may thus be important for the localization of PI3K_68D, allowing it to modify signaling pathways downstream of cell surface receptors. The phenotypes obtained are markedly distinct from those generated by expression of the Drosophila class I PI3K, which affects growth but not pattern formation.

scholarly journals R-Ras Controls Membrane Protrusion and Cell Migration through the Spatial Regulation of Rac and Rho

2005 ◽  
Vol 16 (1) ◽  
pp. 84-96 ◽  
Author(s):  
Michele A. Wozniak ◽  
Lina Kwong ◽  
David Chodniewicz ◽  
Richard L. Klemke ◽  
Patricia J. Keely
Keyword(s):  
Cell Migration ◽  
Molecular Mechanisms ◽  
Leading Edge ◽  
Pi3 Kinase ◽  
Dominant Negative ◽  
Cell Periphery ◽  
Membrane Protrusion ◽  
Spatial Regulation ◽  
Entire Cell ◽  
Migratory Cells

Although it is known that the spatial coordination of Rac and Rho activity is essential for cell migration, the molecular mechanisms regulating these GTPases during migration are unknown. We found that the expression of constitutively activated R-Ras (38V) blocked membrane protrusion and random migration. In contrast, expression of dominant negative R-Ras (41A) enhanced migrational persistence and membrane protrusion. Endogenous R-Ras is necessary for cell migration, as cells that were transfected with siRNA for R-Ras did not migrate. Expression of R-Ras (38V) decreased Rac activity and increased Rho activity around the entire cell periphery, whereas expression of dominant negative R-Ras (41A) showed the converse, suggesting that R-Ras can spatially activate Rho and inactivate Rac. Consistent with this role, endogenous R-Ras localized and was preferentially activated at the leading edge of migratory cells in response to adhesion. The effects of R-Ras on cell migration are mediated by PI3-Kinase, as an effector mutant that uncouples PI3-Kinase binding from R-Ras (38V) rescued migration. From these data, we hypothesize that R-Ras plays a key role in cell migration by locally regulating the switch from Rac to Rho activity after membrane protrusion and adhesion.

scholarly journals The Class II Phosphoinositide 3-Kinase C2β Is Not Essential for Epidermal Differentiation

2005 ◽  
Vol 25 (24) ◽  
pp. 11122-11130 ◽  
Author(s):  
Kazutoshi Harada ◽  
Amy B. Truong ◽  
Ti Cai ◽  
Paul A. Khavari
Keyword(s):  
Class Ii ◽  
Epidermal Cells ◽  
Epidermal Differentiation ◽  
Class I ◽  
Differentiation Markers ◽  
Cellular Processes ◽  
Targeted Gene Deletion ◽  
Epidermal Growth ◽  
Phosphoinositide 3 Kinase

ABSTRACT Phosphoinositide 3-kinases (PI3Ks) regulate an array of cellular processes and are comprised of three classes. Class I PI3Ks include the well-studied agonist-sensitive p110 isoforms; however, the functions of class II and III PI3Ks are less well characterized. Of the three class II PI3Ks, C2α and C2β are widely expressed in many tissues, including the epidermis, while C2γ is confined to the liver. In contrast to the class I PI3K p110α, which is expressed throughout the epidermis, C2β was found to be localized in suprabasal cells, suggesting a potential role for C2β in epidermal differentiation. Overexpressing C2β in epidermal cells in vitro induced differentiation markers. To study a role for C2β in tissue, we generated transgenic mice overexpressing C2β in both suprabasal and basal epidermal layers. These mice lacked epidermal abnormalities. Mice deficient in C2β were then generated by targeted gene deletion. C2β knockout mice were viable and fertile and displayed normal epidermal growth, differentiation, barrier function, and wound healing. To exclude compensation by C2α, RNA interference was then used to knock down both C2α and C2β in epidermal cells simultaneously. Induction of differentiation markers was unaffected in the absence of C2α and C2β. These findings indicate that class II PI3Ks are not essential for epidermal differentiation.

Antrodia cinnamomea Inhibits Migration in Human Hepatocellular Carcinoma Cells: The Role of ERp57 and PGK-1

2015 ◽  
Vol 43 (08) ◽  
pp. 1671-1696 ◽  
Author(s):  
Ying-Yi Chen ◽  
Fon-Chang Liu ◽  
Tian-Shung Wu ◽  
Ming-Jyh Sheu
Keyword(s):  
Hepatocellular Carcinoma ◽  
Cell Migration ◽  
Molecular Mechanisms ◽  
Ethanol Extract ◽  
Mapk Signaling ◽  
Active Ingredients ◽  
Down Regulation ◽  
Antrodia Cinnamomea ◽  
Protein Expressions ◽  
And Migration

Evidences suggest that ERp57 and PGK-1 signaling lead to cancer cell proliferation and migration. We hypothesized that ERp57 and PGK-1 down-regulation may inactivate matrix metalloproteinase (MMP)-2, -9 expressions and inhibit hepatocellular carcinoma (HCC) migration. Antrodia cinnamomea is widely prescribed as an adjuvant to treat HCC in Taiwan. We aimed to investigate if ethanol extract of fruiting bodies of Antrodia cinnamomea (EEAC) and its active ingredients (i.e., zhankuic acid A, cordycepin, and adenosine) can modulate HCC cancer cells migration through ERp57 and PGK-1 and other molecular pathways such as PI3K/Akt and MAPK. ERp57 and PGK-1 siRNA were transfected into HCC to determine effects on MMP-2/-9 expressions and cell migration. We then examined the inhibitory effects of EEAC and its active ingredients on HCC migration and its related mechanisms including ERp57, PGK-1, PI3K/Akt, and MAPK signaling pathways. Down-regulation of ERp57 and PGK-1 by siRNA decreased MMP-2, -9 expressions and Transwell cell migration in HCC. Nontoxic EEAC markedly inhibited migration of HCC, and significantly inhibited activities and protein expressions of MMP-2 and -9, while the expression of the endogenous inhibitors (TIMP-1 and TIMP-2) of these proteins increased. Nontoxic EEAC and its active ingredients decreased ERp57, GLUD-1, GST-pi, and PGK-1 protein expressions. Finally, nontoxic EEAC inhibited the phosphorylated FAK, PI3K/Akt, and MAPK signaling. Our findings first indicate that EEAC and its ingredients effectively suppress HCC migration. Additionally, the molecular mechanisms appear to be mediated, in part, through the down-regulation of ERp57, PGK-1, MAPK, and PI3K/Akt.

scholarly journals Mechanosensitive Expression of Lamellipodin Governs Cell Cycle Progression and Intracellular Stiffness

2020 ◽  
Author(s):  
Joseph A. Brazzo ◽  
Kwonmoo Lee ◽  
Yongho Bae
Keyword(s):  
Cell Cycle ◽  
Cell Proliferation ◽  
Cell Migration ◽  
Cell Cycle Progression ◽  
Molecular Mechanisms ◽  
Cycle Progression ◽  
Cellular Processes ◽  
M Phase ◽  
And Migration ◽  
In Cells

SUMMARYCells exhibit pathological behaviors in response to increased extracellular matrix (ECM) stiffness, including accelerated cell proliferation and migration [1–9], which are correlated with increased intracellular stiffness and tension [2, 3, 10–12]. The biomechanical signal transduction of ECM stiffness into relevant molecular signals and resultant cellular processes is mediated through multiple proteins associated with the actin cytoskeleton in lamellipodia [2, 3, 10, 11, 13]. However, the molecular mechanisms by which lamellipodial dynamics regulate cellular responses to ECM stiffening remain unclear. Previous work described that lamellipodin, a phosphoinositide- and actin filament-binding protein that is known mostly for controlling cell migration [14–21], promotes ECM stiffness-mediated early cell cycle progression [2], revealing a potential commonality between the mechanisms controlling stiffness-dependent cell migration and those controlling cell proliferation. However, i) whether and how ECM stiffness affects the levels of lamellipodin expression and ii) whether stiffness-mediated lamellipodin expression is required throughout cell cycle progression and for intracellular stiffness have not been explored. Here, we show that the levels of lamellipodin expression in cells are significantly increased by a stiff ECM and that this stiffness-mediated lamellipodin upregulation persistently stimulates cell cycle progression and intracellular stiffness throughout the cell cycle, from the early G1 phase to M phase. Finally, we show that both Rac activation and intracellular stiffening are required for the mechanosensitive induction of lamellipodin. More specifically, inhibiting Rac1 activation in cells on stiff ECM reduces the levels of lamellipodin expression, and this effect is reversed by the overexpression of activated Rac1 in cells on soft ECM. We thus propose that lamellipodin is a critical molecular lynchpin in the control of mechanosensitive cell cycle progression and intracellular stiffness.

scholarly journals Sphingosine 1-Phosphate-induced Endothelial Cell Migration Requires the Expression of EDG-1 and EDG-3 Receptors and Rho-dependent Activation of αvβ3- and β1-containing Integrins

2001 ◽  
Vol 276 (15) ◽  
pp. 11830-11837 ◽  
Author(s):  
Ji H. Paik ◽  
Sung-suk Chae ◽  
Menq-Jer Lee ◽  
Shobha Thangada ◽  
Timothy Hla
Keyword(s):  
Cell Migration ◽  
Endothelial Cell ◽  
Molecular Mechanisms ◽  
Cell Attachment ◽  
Endothelial Cell Migration ◽  
Endothelial Differentiation ◽  
Focal Contact ◽  
Sphingosine 1 Phosphate ◽  
And Migration ◽  
Differentiation Gene

Sphingosine 1-phosphate (SPP), a platelet-derived bioactive lysophospholipid, is a regulator of angiogenesis. However, molecular mechanisms involved in SPP-induced angiogenic responses are not fully defined. Here we report the molecular mechanisms involved in SPP-induced human umbilical vein endothelial cell (HUVEC) adhesion and migration. SPP-induced HUVEC migration is potently inhibited by antisense phosphothioate oligonucleotides against EDG-1 as well as EDG-3 receptors. In addition, C3 exotoxin blocked SPP-induced cell attachment, spreading and migration on fibronectin-, vitronectin- and Matrigel-coated surfaces, suggesting that endothelial differentiation gene receptor signaling via the Rho pathway is critical for SPP-induced cell migration. Indeed, SPP induced Rho activation in an adherence-independent manner, whereas Rac activation was dispensible for cell attachment and focal contact formation. Interestingly, both EDG-1 and -3 receptors were required for Rho activation. Since integrins are critical for cell adhesion, migration, and angiogenesis, we examined the effects of blocking antibodies against αvβ3, β1, or β3integrins. SPP induced Rho-dependent integrin clustering into focal contact sites, which was essential for cell adhesion, spreading and migration. Blockage of αvβ3- or β1-containing integrins inhibited SPP-induced HUVEC migration. Together our results suggest that endothelial differentiation gene receptor-mediated Rho signaling is required for the activation of integrin αvβ3as well as β1-containing integrins, leading to the formation of initial focal contacts and endothelial cell migration.

scholarly journals Transcriptome and DNA Methylation Analyses of the Molecular Mechanisms Underlying with Longissimus dorsi Muscles at Different Stages of Development in the Polled Yak

Genes ◽  
2019 ◽  
Vol 10 (12) ◽  
pp. 970 ◽  
Author(s):  
Ma ◽  
Jia ◽  
Chu ◽  
Fu ◽  
Lei ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Molecular Mechanisms ◽  
Expression Patterns ◽  
Methylation Status ◽  
Muscle Growth ◽  
Class Ii ◽  
Epigenetic Mechanism ◽  
Class I ◽  
Longissimus Dorsi ◽  
Growth Stages

DNA methylation modifications are implicated in many biological processes. As the most common epigenetic mechanism DNA methylation also affects muscle growth and development. The majority of previous studies have focused on different varieties of yak, but little is known about the epigenetic regulation mechanisms in different age groups of animals. The development of muscles in the different stages of yak growth remains unclear. In this study, we selected the longissimus dorsi muscle tissue at three different growth stages of the yak, namely, 90-day-old fetuses (group E), six months old (group M), and three years old (group A). Using RNA-Seq transcriptome sequencing and methyl-RAD whole-genome methylation sequencing technology, changes in gene expression levels and DNA methylation status throughout the genome were investigated during the stages of yak development. Each group was represented by three biological replicates. The intersections of expression patterns of 7694 differentially expressed genes (DEGs) were identified (padj < 0.01, |log2FC| > 1.2) at each of the three developmental periods. Time-series expression profile clustering analysis indicated that the DEGs were significantly arranged into eight clusters which could be divided into two classes (padj < 0.05), class I profiles that were downregulated and class II profiles that were upregulated. Based on this cluster analysis, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis revealed that DEGs from class I profiles were significantly (padj < 0.05) enriched in 21 pathways, the most enriched pathway being the Axon guidance signaling pathway. DEGs from the class II profile were significantly enriched in 58 pathways, the pathway most strongly enriched being Metabolic pathway. After establishing the methylation profiles of the whole genomes, and using two groups of comparisons, the three combinations of groups (M-vs.-E, M-vs.-A, A-vs.-E) were found to have 1344, 822, and 420 genes, respectively, that were differentially methylated at CCGG sites and 2282, 3056, and 537 genes, respectively, at CCWGG sites. The two sets of data were integrated and the negative correlations between DEGs and differentially methylated promoters (DMPs) analyzed, which confirmed that TMEM8C, IGF2, CACNA1S and MUSTN1 were methylated in the promoter region and that expression of the modified genes was negatively correlated. Interestingly, these four genes, from what was mentioned above, perform vital roles in yak muscle growth and represent a reference for future genomic and epigenomic studies in muscle development, in addition to enabling marker-assisted selection of growth traits.

scholarly journals Structurally related class I and class II receptor protein tyrosine kinases are down-regulated by the same E3 protein coded for by human group C adenoviruses.

1993 ◽  
Vol 120 (5) ◽  
pp. 1271-1279 ◽  
Author(s):  
E Kuivinen ◽  
B L Hoffman ◽  
P A Hoffman ◽  
C R Carlin
Keyword(s):  
Tyrosine Kinases ◽  
Egf Receptor ◽  
Class Ii ◽  
Class I ◽  
Receptor Protein ◽  
Egf Receptors ◽  
Class Iii ◽  
Human Group ◽  
Down Regulation ◽  
In Cells

Receptor tyrosine kinases (RTKs) are grouped into subcategories based on shared sequence and structural features. Human group C adenoviruses down-regulate EGF receptors, which are members of the class I family of RTKs, during the early stages of infection. Adenovirus appears to utilize a nonsaturable intracellular pathway since it causes EGF-R down-regulation even in cells that significantly overexpress EGF-R. Adenovirus-induced down-regulation is mediated by a small hydrophobic molecule coded for by the E3 early transcription region that has recently been localized to plasma membrane. Here we examine intracellular trafficking of other RTKs in adenovirus-infected cells, to better understand the molecular basis for the action of the E3 protein. Although p185c-neu, which is a class I RTK closely related to the EGF receptor, is down-regulated in cells expressing physiological concentrations of this molecule, it is not down-regulated in tumor cell lines that significantly overexpress p185c-neu. Cell surface receptors for insulin and IGF1, which are class II RTKs, are also reduced in cells expressing the E3 protein, although to a slightly lesser extent than the EGF receptor. Moreover, whereas EGF receptors are degraded between 3- and 9-h postinfection, insulin and IGF1 receptors are degraded between 6- and 12-h postinfection under identical conditions. In contrast to the class I and class II RTKs, there is no difference in the expression of the class III receptors for PDGF and aFGF in cells infected with a virus with an intact E3 region versus a virus mutant with an internal deletion in the relevant E3 gene. These results suggest that the E3 protein provides an internalization and degradative sorting signal for some class I and class II RTKs, although down-regulation of class II RTKs is somewhat less efficient. Molecular recognition of class I and class II RTKs during adenovirus infection may not be due strictly to amino acid structure, however, since EGF-R but not p185c-neu is down-regulated in cells where it is significantly overexpressed.

The class II phosphoinositide 3-kinase PI3K-C2β regulates cell migration by a PtdIns(3)P dependent mechanism

2005 ◽  
Vol 205 (3) ◽  
pp. 452-462 ◽  
Author(s):  
Jan Domin ◽  
Lisa Harper ◽  
Deborah Aubyn ◽  
Matthew Wheeler ◽  
Oliver Florey ◽  
...  
Keyword(s):  
Cell Migration ◽  
Class Ii ◽  
Phosphoinositide 3 Kinase ◽  
Dependent Mechanism
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