scholarly journals A RhoA and Rnd3 cycle regulates actin reassembly during membrane blebbing

2016 ◽  
Vol 113 (13) ◽  
pp. E1863-E1871 ◽  
Author(s):  
Kana Aoki ◽  
Fumiyo Maeda ◽  
Tomoya Nagasako ◽  
Yuki Mochizuki ◽  
Seiichi Uchida ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Actin Cytoskeleton ◽  
Molecular Mechanisms ◽  
Growth Factor Receptor ◽  
Kinase Substrate ◽  
Membrane Blebbing ◽  
Actin Cortex ◽  
Membrane Blebs ◽  
Epidermal Growth ◽  
Intracellular Pressure

The actin cytoskeleton usually lies beneath the plasma membrane. When the membrane-associated actin cytoskeleton is transiently disrupted or the intracellular pressure is increased, the plasma membrane detaches from the cortex and protrudes. Such protruded membrane regions are called blebs. However, the molecular mechanisms underlying membrane blebbing are poorly understood. This study revealed that epidermal growth factor receptor kinase substrate 8 (Eps8) and ezrin are important regulators of rapid actin reassembly for the initiation and retraction of protruded blebs. Live-cell imaging of membrane blebbing revealed that local reassembly of actin filaments occurred at Eps8- and activated ezrin-positive foci of membrane blebs. Furthermore, we found that a RhoA–ROCK–Rnd3 feedback loop determined the local reassembly sites of the actin cortex during membrane blebbing.

scholarly journals Cell motility through plasma membrane blebbing

2008 ◽  
Vol 181 (6) ◽  
pp. 879-884 ◽  
Author(s):  
Oliver T. Fackler ◽  
Robert Grosse
Keyword(s):  
Plasma Membrane ◽  
Cell Motility ◽  
Molecular Mechanisms ◽  
Cell Movement ◽  
Core Component ◽  
Membrane Blebbing ◽  
Membrane Blebs ◽  
Bleb Formation ◽  
Guanosine Triphosphatase

Plasma membrane blebs are dynamic cytoskeleton-regulated cell protrusions that have been implicated in apoptosis, cytokinesis, and cell movement. Influencing Rho–guanosine triphosphatase activities and subsequent actomyosin dynamics appears to constitute a core component for bleb formation. In this paper, we discuss recent evidence in support of a central role of nonapoptotic membrane blebbing for cell migration and cancer cell invasion as well as advances in our understanding of the underlying molecular mechanisms. Based on these studies, we propose that in a physiological context, bleb-associated cell motility reflects a cell's response to reduced substratum adhesion. The importance of blebbing as a functional protrusion is underscored by the existence of multiple molecular mechanisms that govern actin-mediated bleb retraction.

scholarly journals Epidermal Growth Factor Receptor Distribution during Chemotactic Responses

2000 ◽  
Vol 11 (11) ◽  
pp. 3873-3883 ◽  
Author(s):  
Maryse Bailly ◽  
Jeffrey Wyckoff ◽  
Boumediene Bouzahzah ◽  
Ross Hammerman ◽  
Vonetta Sylvestre ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Egf Receptor ◽  
Fluorescent Protein ◽  
Growth Factor Receptor ◽  
Spatial Gradient ◽  
Spatial Gradients ◽  
Epidermal Growth ◽  
Green Fluorescent

To determine the distribution of the epidermal growth factor (EGF) receptor (EGFR) on the surface of cells responding to EGF as a chemoattractant, an EGFR-green fluorescent protein chimera was expressed in the MTLn3 mammary carcinoma cell line. The chimera was functional and easily visualized on the cell surface. In contrast to other studies indicating that the EGFR might be localized to certain regions of the plasma membrane, we found that the chimera is homogeneously distributed on the plasma membrane and becomes most concentrated in vesicles after endocytosis. In spatial gradients of EGF, endocytosed receptor accumulates on the upgradient side of the cell. Visualization of the binding of fluorescent EGF to cells reveals that the affinity properties of the receptor, together with its expression level on cells, can provide an initial amplification step in spatial gradient sensing.

Orientation of the v-erb-B gene product in the plasma membrane

1986 ◽  
Vol 6 (4) ◽  
pp. 1329-1333
Author(s):  
R C Schatzman ◽  
G I Evan ◽  
M L Privalsky ◽  
J M Bishop
Keyword(s):  
Endoplasmic Reticulum ◽  
Epidermal Growth Factor Receptor ◽  
Plasma Membrane ◽  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Growth Factor Receptor ◽  
Kinase Domain ◽  
Amino Terminus ◽  
Protein Kinase Domain ◽  
Epidermal Growth

The retroviral oncogene v-erb-B encodes a truncated version of the receptor for epidermal growth factor. To define the disposition of the v-erb-B protein within cells and across the plasma membrane, we raised antibodies against defined epitopes in the protein and used these in immunofluorescence to analyze cells transformed by v-erb-B. A small fraction of the v-erb-B protein was found on the plasma membrane in a clustered configuration. The bulk of the protein was located in the endoplasmic reticulum and Golgi apparatus. Epitopes near the amino terminus of the v-erb-B protein were displayed on the surface of the cell, whereas epitopes in the protein kinase domain were located exclusively within cells. We conclude that the v-erb-B protein spans the plasma membrane in a manner similar or identical to that of the epidermal growth factor receptor, even though the viral transforming protein does not possess the signal peptide that is thought to direct insertion of the receptor into the membrane.

scholarly journals Molecular mechanisms of epidermal growth factor receptor overexpression in patients with cervical cancer

2011 ◽  
Vol 24 (5) ◽  
pp. 720-728 ◽  
Author(s):  
Marlies Schrevel ◽  
Arko Gorter ◽  
Sandra M Kolkman-Uljee ◽  
J Baptist M Z Trimbos ◽  
Gert Jan Fleuren ◽  
...  
Keyword(s):  
Cervical Cancer ◽  
Epidermal Growth Factor Receptor ◽  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Molecular Mechanisms ◽  
Growth Factor Receptor ◽  
Epidermal Growth

scholarly journals The chemotactic factor N-formylmethionyl-leucyl-phenylalanine activates microtubule-associated protein 2 (MAP) kinase and a MAP kinase kinase in polymorphonuclear leucocytes

1993 ◽  
Vol 290 (2) ◽  
pp. 483-488 ◽  
Author(s):  
H L Thompson ◽  
M Shiroo ◽  
J Saklatvala
Keyword(s):  
Map Kinase ◽  
Map Kinases ◽  
Gel Filtration ◽  
Growth Factor Receptor ◽  
Chemotactic Factor ◽  
Polymorphonuclear Leucocytes ◽  
Kinase Substrate ◽  
Extracellular Signal ◽  
Epidermal Growth ◽  
Kinase Substrates

Incubation of human polymorphonuclear leucocytes (PMN) with either the chemotactic factor N-formylmethionyl-leucylphenylalanine (FMLP) or phorbol 12-myristate 13-acetate (PMA) activates a kinase with phosphorylating activity towards a known microtubule-associated protein-2 (MAP) kinase substrate, the epidermal growth factor receptor peptide (T669). Activation of this enzyme by FMLP was maximal at 1 min, decreasing by 10 min. Activation by PMA was slightly slower than that by FMLP, but more prolonged (maximal at 5 min, with no significant decrease by 20 min). The enzyme induced by either stimulant bound strongly to phenyl-Sepharose, had a molecular mass of 40 kDa on gel filtration and phosphorylated three MAP kinase substrates, i.e. MAP, myelin basic protein and the T669 peptide. By use of antibodies to MAP kinases and phosphotyrosine, the enzyme was identified as the 42 kDa MAP kinase (also known as extracellular-signal-regulated kinase 2, ERK2). Stimulation of PMN with FMLP or PMA was also found to induce a kinase kinase which phosphorylated human recombinant MAP kinase on threonine and tyrosine, with concomitant activation. These results suggest that MAP kinase and the kinase kinase are involved in the activation of PMN by chemotactic factors such as FMLP.

Drug-induced alterations in Mg2+ homoeostasis

2012 ◽  
Vol 123 (1) ◽  
pp. 1-14 ◽  
Author(s):  
Anke L. Lameris ◽  
Leo A. Monnens ◽  
René J. Bindels ◽  
Joost G. J. Hoenderop
Keyword(s):  
Adverse Effects ◽  
Molecular Mechanisms ◽  
Growth Factor Receptor ◽  
Calcineurin Inhibitors ◽  
Drug Induced ◽  
Neuromuscular Abnormalities ◽  
Broad Variety ◽  
Epidermal Growth ◽  
High Doses ◽  
Insight Into

Magnesium (Mg2+) balance is tightly regulated by the concerted actions of the intestine, bone and kidneys. This balance can be disturbed by a broad variety of drugs. Diuretics, modulators of the EGFR (epidermal growth factor receptor), proton pump inhibitors, antimicrobials, calcineurin inhibitors and cytostatics may all cause hypomagnesaemia, potentially leading to tetany, seizures and cardiac arrhythmias. Conversely, high doses of Mg2+ salts, frequently administered as an antacid or a laxative, may lead to hypermagnesaemia causing various cardiovascular and neuromuscular abnormalities. A better understanding of the molecular mechanisms underlying the adverse effects of these medications on Mg2+ balance will indicate ways of prevention and treatment of these adverse effects and could potentially provide more insight into Mg2+ homoeostasis.

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