scholarly journals Feedback Microtubule Control and Microtubule-Actin Cross-talk inArabidopsisRevealed by Integrative Proteomic and Cell Biology Analysis ofKATANIN 1Mutants

2017 ◽  
Vol 16 (9) ◽  
pp. 1591-1609 ◽  
Author(s):  
Tomáš Takáč ◽  
Olga Šamajová ◽  
Tibor Pechan ◽  
Ivan Luptovčiak ◽  
Jozef Šamaj
Keyword(s):  
Cross Talk ◽  
Cell Biology

scholarly journals Insulin signalling: putting the G- in protein-protein interactions

2004 ◽  
Vol 380 (1) ◽  
pp. e11-e12 ◽  
Author(s):  
Craig C. MALBON
Keyword(s):  
Insulin Receptor ◽  
Cross Talk ◽  
Protein Interactions ◽  
Tyrosine Kinases ◽  
Cell Biology ◽  
Receptor Tyrosine Kinases ◽  
Insulin Signalling ◽  
Cell Signalling ◽  
Protein Protein Interactions ◽  
Proximal Point

Cell signalling via receptor tyrosine kinases, such as the insulin receptor, and via heterotrimeric G-proteins, such as Gαi, Gαs and Gαq family members, constitute two of most avidly studied paradigms in cell biology. That elements of these two populous signalling pathways must cross-talk to achieve proper signalling in the regulation of cell proliferation, differentiation and metabolism has been anticipated, but the evolution of our thinking and the analysis of such cross-talk have lagged behind the ever-expanding troupe of players and the recognition of multivalency as the rule, rather than the exception, in signalling biology. New insights have been provided by Kreuzer et al. in this issue of the Biochemical Journal, in which insulin is shown to provoke recruitment of Gαi-proteins to insulin-receptor-based complexes that can regulate the gain of insulin-receptor-catalysed autophosphorylation, a proximal point in the insulin-sensitive cascade of signalling. Understanding the convergence and cross-talk of signals from the receptor tyrosine kinases and G-protein-coupled receptor pathways in physical, spatial and temporal contexts will remain a major challenge of cell biology.

Mechanisms behind the puzzle: microtubule–microfilament cross-talk in pavement cell formationThis review is one of a selection of papers published in the Special Issue on Plant Cell Biology.

2006 ◽  
Vol 84 (4) ◽  
pp. 594-603 ◽  
Author(s):  
A.M. Kotzer ◽  
G.O. Wasteneys
Keyword(s):  
Cross Talk ◽  
Cell Biology ◽  
Actin Polymerization ◽  
Small Gtpases ◽  
Wall Material ◽  
Pavement Cell ◽  
Pavement Cells ◽  
Actin Microfilament ◽  
Wide Range ◽  
Actin Patch

Recent studies are revealing plausible mechanisms that help explain how the two major cytoskeletal systems of plant cells interact to co-ordinate morphogenesis in diffusely expanding cells. In this article, we focus on the development of pavement cells typically found in the leaf epidermis, and highlight work that provides insights into the mechanisms that generate their complex morphology. Pavement cells interdigitate with adjacent cells, forming narrow neck regions interspersed with lobe-like projections. Earlier analysis demonstrated that distinct banding of cortical microtubules and associated accumulation of cell wall material was responsible for maintaining the neck regions during expansion. More recently, it has been determined that patches of fine actin microfilaments regulate the formation of lobing regions. This zonation into microtubule-rich bands and actin patches is coordinated by the activity of Rops, small GTPases that control a wide range of signalling pathways including ones that remodel both actin microfilament and microtubule arrays. Moreover, the formation of microtubule bands and actin patches seems to be self-reinforcing. Loss of microtubule polymers by drug treatment or mutation broadens actin patch formation, apparently by enhancing Rop interactions with a positive regulator of actin polymerization. Thus, cross-talk between microtubule and actin microfilament networks is essential for coordinating and reinforcing pavement cell morphogenesis.

scholarly journals Cross-talk between Rho and Rac GTPases drives deterministic exploration of cellular shape space and morphological heterogeneity

Open Biology ◽  
2014 ◽  
Vol 4 (1) ◽  
pp. 130132 ◽  
Author(s):  
Heba Sailem ◽  
Vicky Bousgouni ◽  
Sam Cooper ◽  
Chris Bakal
Keyword(s):  
Cross Talk ◽  
Rho Gtpases ◽  
Cell Biology ◽  
Cell Shape ◽  
Graphical Model ◽  
Shape Space ◽  
Boolean Model ◽  
Complex Nature ◽  
Morphological Heterogeneity ◽  
Cell Shapes

One goal of cell biology is to understand how cells adopt different shapes in response to varying environmental and cellular conditions. Achieving a comprehensive understanding of the relationship between cell shape and environment requires a systems-level understanding of the signalling networks that respond to external cues and regulate the cytoskeleton. Classical biochemical and genetic approaches have identified thousands of individual components that contribute to cell shape, but it remains difficult to predict how cell shape is generated by the activity of these components using bottom-up approaches because of the complex nature of their interactions in space and time. Here, we describe the regulation of cellular shape by signalling systems using a top-down approach. We first exploit the shape diversity generated by systematic RNAi screening and comprehensively define the shape space a migratory cell explores. We suggest a simple Boolean model involving the activation of Rac and Rho GTPases in two compartments to explain the basis for all cell shapes in the dataset. Critically, we also generate a probabilistic graphical model to show how cells explore this space in a deterministic, rather than a stochastic, fashion. We validate the predictions made by our model using live-cell imaging. Our work explains how cross-talk between Rho and Rac can generate different cell shapes, and thus morphological heterogeneity, in genetically identical populations.

scholarly journals The Effect of Orthognathic Surgery on Osteoprotegerin as Immunological Caliper of Bone Healing

2016 ◽  
Vol 4 (4) ◽  
pp. 705-708
Author(s):  
Sara Soliman ◽  
Mamdouh Ahmed
Keyword(s):  
Bone Mass ◽  
Cross Talk ◽  
Bone Healing ◽  
Cell Biology ◽  
Orthognathic Surgery ◽  
Healing Process ◽  
Bone Cell ◽  
Control Group ◽  
Blood Samples ◽  
Healing Period

BACKGROUND: Osteoprotegerin (OPG) is considered to be the cytokine that plays an important role in the healing process. OPG regulates bone cell biology, osteoblast–osteoclast, bone-immune cross-talk and maintenance of bone mass. It plays an important role in the development, induction, and repair of bone. Orthognathic surgery as multiples segmental osteotomies has been taken as a model surgery to assess the changes in osteoprotegerin levels in the post-operative bone healing period.AIM: The aim of the study was to evaluate OPG as immunological caliper of bone healing.MATERIAL AND METHODS: OPG was evaluated in nine patients seeking orthognathic surgery. Patients were examined and checked to be medically and immunologically free prior to surgery. Blood samples were collected immediate pre-operative as control group and for six weeks post-operative as study group.RESULTS: Data were collected from nine consecutive patients. The results showed higher levels of OPG. it showed significant increase in the immediate post-operative value (p = 0.001) which started to increase gradually during the six weeks (p < 0.001).CONCLUSIONS: Significant higher levels of OPG during the healing period of orthognathic surgery suggest the its use as immunological caliper of bone healing.

The Esophageal Cancer and the PI3K/AKT/mTOR Signaling Regulatory microRNAs: a Novel Marker for Prognosis, and a Possible Target for Immunotherapy

2019 ◽  
Vol 24 (39) ◽  
pp. 4646-4651 ◽  
Author(s):  
Seyed A. Javadinia ◽  
Soodabeh Shahidsales ◽  
Azar Fanipakdel ◽  
Asma Mostafapour ◽  
Mona Joudi-Mashhad ◽  
...  
Keyword(s):  
Esophageal Cancer ◽  
Cross Talk ◽  
Therapeutic Target ◽  
Cell Biology ◽  
Current Knowledge ◽  
Mammalian Target Of Rapamycin ◽  
Mtor Pathway ◽  
Mtor Signaling ◽  
Phosphatidylinositol 3 Kinase ◽  
Potential Therapeutic Target

The Phosphatidylinositol 3-kinase/AKT/Mammalian Target of Rapamycin (PI3K/AKT/mTOR) pathway has a critical regulatory role in cell biology including translation, transcription, and autophagy. Dysregulation of this pathway is involved in the pathogenesis, development, and prognosis of esophageal cancer that has been assessed in the recent years and its potential as a target in therapy. This report summarizes the current knowledge about PI3K/AKT/mTOR pathway and its cross-talk with a focus on the value of targeting this pathway as a potential therapeutic target in the treatment of esophageal cancer.

scholarly journals Effect of Ganglioside and Tetraspanins in Microdomains on Interaction of Integrins with Fibroblast Growth Factor Receptor

2005 ◽  
Vol 280 (16) ◽  
pp. 16227-16234 ◽  
Author(s):  
Marcos S. Toledo ◽  
Erika Suzuki ◽  
Kazuko Handa ◽  
Senitiroh Hakomori
Keyword(s):  
Growth Factor ◽  
Fibroblast Growth Factor ◽  
Tyrosine Phosphorylation ◽  
Cross Talk ◽  
Cell Biology ◽  
Time Course ◽  
Basic Mechanism ◽  
Fibroblast Growth ◽  
Ganglioside Gm3 ◽  
Ceramide Level

The functional interaction (“cross-talk”) of integrins with growth factor receptors has become increasingly clear as a basic mechanism in cell biology, defining cell growth, adhesion, and motility. However, no studies have addressed the microdomains in which such interaction takes place nor the effect of gangliosides and tetraspanins (TSPs) on such interaction. Growth of human embryonal WI38 fibroblasts is highly dependent on fibroblast growth factor (FGF) and its receptor (FGFR), stably associated with ganglioside GM3 and TSPs CD9 and CD81 in the ganglioside-enriched microdomain. Adhesion and motility of these cells are mediated by laminin-5 ((LN5) and fibronectin (FN) through α3β1 and α5β1 integrin receptors, respectively. When WI38 cells or its transformant VA13 cells were adhered to LN5 or FN, α3β1 or α5β1 were stimulated, giving rise to signaling to activate FGFR through tyrosine phosphorylation and inducing cell proliferation under serum-free conditions without FGF addition. Types and intensity of signaling during the time course differed significantly depending on the type of integrin stimulated (α3β1versusα5β1), and on cell type (WI38versusVA13). Such effect of cross-talk between integrins and FGFR was influenced strongly by the change of GM3 and TSPs. (i) GM3 depletion by P4 caused enhanced tyrosine phosphorylation of FGFR and Akt followed by MAPK activation, without significant change of ceramide level. GM3 depletion also caused enhanced co-immunoprecipitation of FGFR with α3/α5/β1 and of these integrins with CD9/CD81. (ii) LN5- or FN-dependent proliferation of both WI38 and VA13 was strongly enhanced by GM3 depletion and by CD9/CD81 knockdown by siRNA. Thus, integrin-FGFR cross-talk is strongly influenced by GM3 and/or TSPs within the ganglioside-enriched microdomain.

scholarly journals Cross talk between microRNA and epigenetic regulation in adult neurogenesis

2010 ◽  
Vol 189 (1) ◽  
pp. 127-141 ◽  
Author(s):  
Keith E. Szulwach ◽  
Xuekun Li ◽  
Richard D. Smrt ◽  
Yujing Li ◽  
Yuping Luo ◽  
...  
Keyword(s):  
Stem Cells ◽  
Epigenetic Regulation ◽  
Cross Talk ◽  
Adult Neurogenesis ◽  
Cell Biology ◽  
Polycomb Group ◽  
Stem Cell Biology ◽  
Proliferation And Differentiation

Both microRNAs (miRNAs) and epigenetic regulation have important functions in stem cell biology, although the interactions between these two pathways are not well understood. Here, we show that MeCP2, a DNA methyl-CpG–binding protein, can epigenetically regulate specific miRNAs in adult neural stem cells (aNSCs). MeCP2-mediated epigenetic regulation of one such miRNA, miR-137, involves coregulation by Sox2, a core transcription factor in stem cells. miR-137 modulates the proliferation and differentiation of aNSCs in vitro and in vivo. Overexpression of miR-137 promotes the proliferation of aNSCs, whereas a reduction of miR-137 enhances aNSC differentiation. We further show that miR-137 post-transcriptionally represses the expression of Ezh2, a histone methyltransferase and Polycomb group (PcG) protein. The miR-137–mediated repression of Ezh2 feeds back to chromatin, resulting in a global decrease in histone H3 trimethyl lysine 27. Coexpression of Ezh2 can rescue phenotypes associated with miR-137 overexpression. These results demonstrate that cross talk between miRNA and epigenetic regulation contributes to the modulation of adult neurogenesis.

Ultrastructure of Some Planktonic Formainifera

1974 ◽  
Vol 32 ◽  
pp. 190-191
Author(s):  
William H. Zucker
Keyword(s):  
Cell Biology ◽  
Water Mass ◽  
Planktonic Foraminifera ◽  
Uranyl Acetate ◽  
Ethanol Dehydration ◽  
Globigerinoides Ruber ◽  
Light Microscope Level ◽  
Globigerina Bulloides ◽  
Glutaraldehyde Solution ◽  
Diamond Knife

Planktonic foraminifera are widely-distributed and abundant zooplankters. They are significant as water mass indicators and provide evidence of paleotemperatures and events which occurred during Pleistocene glaciation. In spite of their ecological and paleological significance, little is known of their cell biology. There are few cytological studies of these organisms at the light microscope level and some recent reports of their ultrastructure.Specimens of Globigerinoides ruber, Globigerina bulloides, Globigerinoides conglobatus and Globigerinita glutinata were collected in Bermuda waters and fixed in a cold cacodylate-buffered 6% glutaraldehyde solution for two hours. They were then rinsed, post-fixed in Palade's fluid, rinsed again and stained with uranyl acetate. This was followed by graded ethanol dehydration, during which they were identified and picked clean of debris. The specimens were finally embedded in Epon 812 by placing each organism in a separate BEEM capsule. After sectioning with a diamond knife, stained sections were viewed in a Philips 200 electron microscope.

Introduction

1978 ◽  
Vol 36 (3) ◽  
pp. 543-544
Author(s):  
W. Bernard
Keyword(s):  
Molecular Weight ◽  
Electron Microscope ◽  
Nucleic Acid ◽  
Gene Mapping ◽  
Molecular Genetics ◽  
Cell Biology ◽  
Gene Activity ◽  
Close Connection ◽  
Basic Information ◽  
Simple Systems

In comparison to many other fields of ultrastructural research in Cell Biology, the successful exploration of genes and gene activity with the electron microscope in higher organisms is a late conquest. Nucleic acid molecules of Prokaryotes could be successfully visualized already since the early sixties, thanks to the Kleinschmidt spreading technique - and much basic information was obtained concerning the shape, length, molecular weight of viral, mitochondrial and chloroplast nucleic acid. Later, additonal methods revealed denaturation profiles, distinction between single and double strandedness and the use of heteroduplexes-led to gene mapping of relatively simple systems carried out in close connection with other methods of molecular genetics.

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