scholarly journals Gαs promotes EEA1 endosome maturation and shuts down proliferative signaling through interaction with GIV (Girdin)

2012 ◽  
Vol 23 (23) ◽  
pp. 4623-4634 ◽  
Author(s):  
Anthony O. Beas ◽  
Vanessa Taupin ◽  
Carmen Teodorof ◽  
Lien T. Nguyen ◽  
Mikel Garcia-Marcos ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Epidermal Growth Factor Receptor ◽  
Growth Factor ◽  
Growth Factor Receptor ◽  
Egfr Signaling ◽  
Early Endosomes ◽  
Epidermal Growth ◽  
Survival Signaling ◽  
Endosome Maturation ◽  
Proliferative Signaling

The organization of the endocytic system into biochemically distinct subcompartments allows for spatial and temporal control of the strength and duration of signaling. Recent work has established that Akt cell survival signaling via the epidermal growth factor receptor (EGFR) occurs from APPL early endosomes that mature into early EEA1 endosomes. Less is known about receptor signaling from EEA1 endosomes. We show here that EGF-induced, proliferative signaling occurs from EEA1 endosomes and is regulated by the heterotrimeric G protein Gαs through interaction with the signal transducing protein GIV (also known as Girdin). When Gαs or GIV is depleted, activated EGFR and its adaptors accumulate in EEA1 endosomes, and EGFR signaling is prolonged, EGFR down-regulation is delayed, and cell proliferation is greatly enhanced. Our findings define EEA1 endosomes as major sites for proliferative signaling and establish that Gαs and GIV regulate EEA1 but not APPL endosome maturation and determine the duration and strength of proliferative signaling from this compartment.

scholarly journals Stimulation of Cell Proliferation by Endosomal Epidermal Growth Factor Receptor As Revealed through Two Distinct Phases of Signaling

2003 ◽  
Vol 23 (16) ◽  
pp. 5803-5815 ◽  
Author(s):  
Steven Pennock ◽  
Zhixiang Wang
Keyword(s):  
Cell Proliferation ◽  
Epidermal Growth Factor Receptor ◽  
Growth Factor ◽  
Growth Factor Receptor ◽  
S Phase ◽  
Egfr Signaling ◽  
Short Pulses ◽  
Endosomal Signaling ◽  
Epidermal Growth ◽  
Stimulate Cell Proliferation

ABSTRACT Strong evidence indicates that endosome-localized epidermal growth factor receptor (EGFR) plays an important role in cell signaling. However, elimination of endosomal signaling does not attenuate EGF-induced physiological outcomes, arguing against physiological relevance. Recently we established a system to specifically activate endosome-associated EGFR in the absence of any plasma membrane activation of EGFR and showed that endosomal EGFR signaling is sufficient to support cell survival. However, this pure endosomal signaling of EGFR does not stimulate cell proliferation, because EGFR only remained activated for less than 2 h following its stimulation at endosomes, while DNA synthesis generally requires growth factor exposure for 8 h or more. Here we report that the prolonged requirement for EGF to stimulate epithelial cell proliferation can be substituted for with two short pulses of EGF. By combining the two short pulses of EGF stimulation with our previously established method to generate endosomal EGFR signaling, we are able to generate two pulses of endosomal EGFR signaling. In this way, we demonstrated that two pulses of endosomal EGFR signaling are sufficient to stimulate cell proliferation. The first pulse of EGFR signaling induces exit from quiescence into G1 phase and appears to render cells responsive to subsequent mitogenic stimulus. This second pulse, required several hours later, drives cells through the restriction point of late G1 and into S phase. We further showed that the two pulses of endosomal EGFR signaling engaged cell cycle machinery the same way as the two pulses of standard EGFR signaling. Moreover, two pulses of endosomal EGFR signaling stimulated downstream signaling cascades in a similar way to the two pulses of standard EGFR activation. The data therefore demonstrate that signals transduced from internalized EGFR, with or without a contribution from the plasma membrane, fully satisfy the physiological requirements for S-phase entry.

scholarly journals Regulation of Epidermal Growth Factor Receptor Signaling by Endocytosis and Intracellular Trafficking

2001 ◽  
Vol 12 (6) ◽  
pp. 1897-1910 ◽  
Author(s):  
Patrick Burke ◽  
Kevin Schooler ◽  
H. Steven Wiley
Keyword(s):  
Epidermal Growth Factor Receptor ◽  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Growth Factor Receptor ◽  
Egfr Signaling ◽  
Egfr Activation ◽  
Early Endosomes ◽  
Epidermal Growth ◽  
Growth Factor Receptor Signaling ◽  
Regulated Trafficking

Ligand activation of the epidermal growth factor receptor (EGFR) leads to its rapid internalization and eventual delivery to lysosomes. This process is thought to be a mechanism to attenuate signaling, but signals could potentially be generated after endocytosis. To directly evaluate EGFR signaling during receptor trafficking, we developed a technique to rapidly and selectively isolate internalized EGFR and associated molecules with the use of reversibly biotinylated anti-EGFR antibodies. In addition, we developed antibodies specific to tyrosine-phosphorylated EGFR. With the use of a combination of fluorescence imaging and affinity precipitation approaches, we evaluated the state of EGFR activation and substrate association during trafficking in epithelial cells. We found that after internalization, EGFR remained active in the early endosomes. However, receptors were inactivated before degradation, apparently due to ligand removal from endosomes. Adapter molecules, such as Shc, were associated with EGFR both at the cell surface and within endosomes. Some molecules, such as Grb2, were primarily found associated with surface EGFR, whereas others, such as Eps8, were found only with intracellular receptors. During the inactivation phase, c-Cbl became EGFR associated, consistent with its postulated role in receptor attenuation. We conclude that the association of the EGFR with different proteins is compartment specific. In addition, ligand loss is the proximal cause of EGFR inactivation. Thus, regulated trafficking could potentially influence the pattern as well as the duration of signal transduction.

scholarly journals Enterococcus faecalis Enhances Cell Proliferation through Hydrogen Peroxide-Mediated Epidermal Growth Factor Receptor Activation

2012 ◽  
Vol 80 (10) ◽  
pp. 3545-3558 ◽  
Author(s):  
Kanitsak Boonanantanasarn ◽  
Ann Lindley Gill ◽  
YoonSing Yap ◽  
Vijayvel Jayaprakash ◽  
Maureen A. Sullivan ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Epidermal Growth Factor Receptor ◽  
Growth Factor ◽  
Oral Cancer ◽  
Growth Factor Receptor ◽  
Egfr Signaling ◽  
Content Type ◽  
Oral Carcinogenesis ◽  
Egfr Activation ◽  
Epidermal Growth

ABSTRACTEnterococcus faecalisis a member of the intestinal and oral microbiota that may affect the etiology of colorectal and oral cancers. The mechanisms by whichE. faecalismay contribute to the initiation and progression of these cancers remain uncertain. Epidermal growth factor receptor (EGFR) signaling is postulated to play a crucial role in oral carcinogenesis. A link betweenE. faecalisand EGFR signaling in oral cancer has not been elucidated. The present study aimed to evaluate the association betweenE. faecalisand oral cancer and to determine the underlying mechanisms that linkE. faecalisto EGFR signaling. We report the high frequency ofE. faecalisinfection in oral tumors and the clinical association with EGFR activation. Using human oral cancer cells, we support the clinical findings and demonstrate thatE. faecaliscan induce EGFR activation and cell proliferation.E. faecalisactivates EGFR through production of H2O2, a signaling molecule that activates several signaling pathways. Inhibitors of H2O2(catalase) and EGFR (gefitinib) significantly blockedE. faecalis-induced EGFR activation and cell proliferation. Therefore,E. faecalisinfection of oral tumor tissues suggests a possible association betweenE. faecalisinfection and oral carcinogenesis. Interaction ofE. faecaliswith host cells and production of H2O2increase EGFR activation, thereby contributing to cell proliferation.

Computational Evaluation and In Vitro Validation of New Epidermal Growth Factor Receptor Inhibitors

2020 ◽  
Vol 20 (18) ◽  
pp. 1628-1639
Author(s):  
Sergi Gómez-Ganau ◽  
Josefa Castillo ◽  
Andrés Cervantes ◽  
Jesus Vicente de Julián-Ortiz ◽  
Rafael Gozalbes
Keyword(s):  
Cell Proliferation ◽  
Epidermal Growth Factor Receptor ◽  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Binding Affinity ◽  
Cell Lines ◽  
Growth Factor Receptor ◽  
Significant Activity ◽  
Epidermal Growth

Background: The Epidermal Growth Factor Receptor (EGFR) is a transmembrane protein that acts as a receptor of extracellular protein ligands of the epidermal growth factor (EGF/ErbB) family. It has been shown that EGFR is overexpressed by many tumours and correlates with poor prognosis. Therefore, EGFR can be considered as a very interesting therapeutic target for the treatment of a large variety of cancers such as lung, ovarian, endometrial, gastric, bladder and breast cancers, cervical adenocarcinoma, malignant melanoma and glioblastoma. Methods: We have followed a structure-based virtual screening (SBVS) procedure with a library composed of several commercial collections of chemicals (615,462 compounds in total) and the 3D structure of EGFR obtained from the Protein Data Bank (PDB code: 1M17). The docking results from this campaign were then ranked according to the theoretical binding affinity of these molecules to EGFR, and compared with the binding affinity of erlotinib, a well-known EGFR inhibitor. A total of 23 top-rated commercial compounds displaying potential binding affinities similar or even better than erlotinib were selected for experimental evaluation. In vitro assays in different cell lines were performed. A preliminary test was carried out with a simple and standard quick cell proliferation assay kit, and six compounds showed significant activity when compared to positive control. Then, viability and cell proliferation of these compounds were further tested using a protocol based on propidium iodide (PI) and flow cytometry in HCT116, Caco-2 and H358 cell lines. Results: The whole six compounds displayed good effects when compared with erlotinib at 30 μM. When reducing the concentration to 10μM, the activity of the 6 compounds depends on the cell line used: the six compounds showed inhibitory activity with HCT116, two compounds showed inhibition with Caco-2, and three compounds showed inhibitory effects with H358. At 2 μM, one compound showed inhibiting effects close to those from erlotinib. Conclusion: Therefore, these compounds could be considered as potential primary hits, acting as promising starting points to expand the therapeutic options against a wide range of cancers.

scholarly journals CG6015 controls spermatogonia transit-amplifying divisions by epidermal growth factor receptor signaling in Drosophila testes

2021 ◽  
Vol 12 (5) ◽  
Author(s):  
Jun Yu ◽  
Qianwen Zheng ◽  
Zhiran Li ◽  
Yunhao Wu ◽  
Yangbo Fu ◽  
...  
Keyword(s):  
Epidermal Growth Factor Receptor ◽  
Stem Cell ◽  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Growth Factor Receptor ◽  
Gene Set Enrichment Analysis ◽  
Germline Stem Cell ◽  
Egfr Signaling ◽  
Egfr Signaling Pathway ◽  
Epidermal Growth

AbstractSpermatogonia transit-amplifying (TA) divisions are crucial for the differentiation of germline stem cell daughters. However, the underlying mechanism is largely unknown. In the present study, we demonstrated that CG6015 was essential for spermatogonia TA-divisions and elongated spermatozoon development in Drosophila melanogaster. Spermatogonia deficient in CG6015 inhibited germline differentiation leading to the accumulation of undifferentiated cell populations. Transcriptome profiling using RNA sequencing indicated that CG6015 was involved in spermatogenesis, spermatid differentiation, and metabolic processes. Gene Set Enrichment Analysis (GSEA) revealed the relationship between CG6015 and the epidermal growth factor receptor (EGFR) signaling pathway. Unexpectedly, we discovered that phosphorylated extracellular regulated kinase (dpERK) signals were activated in germline stem cell (GSC)-like cells after reduction of CG6015 in spermatogonia. Moreover, Downstream of raf1 (Dsor1), a key downstream target of EGFR, mimicked the phenotype of CG6015, and germline dpERK signals were activated in spermatogonia of Dsor1 RNAi testes. Together, these findings revealed a potential regulatory mechanism of CG6015 via EGFR signaling during spermatogonia TA-divisions in Drosophila testes.

scholarly journals A Role for Sorting Nexin 2 in Epidermal Growth Factor Receptor Down-regulation: Evidence for Distinct Functions of Sorting Nexin 1 and 2 in Protein Trafficking

2004 ◽  
Vol 15 (5) ◽  
pp. 2143-2155 ◽  
Author(s):  
Anuradha Gullapalli ◽  
Tiana A. Garrett ◽  
May M. Paing ◽  
Courtney T. Griffin ◽  
Yonghua Yang ◽  
...  
Keyword(s):  
Epidermal Growth Factor Receptor ◽  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Protein Trafficking ◽  
Growth Factor Receptor ◽  
Down Regulation ◽  
Sorting Nexin ◽  
Px Domain ◽  
Early Endosomes ◽  
Epidermal Growth

Sorting nexin 1 (SNX1) and SNX2, homologues of the yeast vacuolar protein-sorting (Vps)5p, contain a phospholipid-binding motif termed the phox homology (PX) domain and a carboxyl terminal coiled-coil region. A role for SNX1 in trafficking of cell surface receptors from endosomes to lysosomes has been proposed; however, the function of SNX2 remains unknown. Toward understanding the function of SNX2, we first examined the distribution of endogenous protein in HeLa cells. We show that SNX2 resides primarily in early endosomes, whereas SNX1 is found partially in early endosomes and in tubulovesicular-like structures distributed throughout the cytoplasm. We also demonstrate that SNX1 interacts with the mammalian retromer complex through its amino terminal domain, whereas SNX2 does not. Moreover, activated endogenous epidermal growth factor receptor (EGFR) colocalizes markedly with SNX2-positive endosomes, but minimally with SNX1-containing vesicles. To assess SNX2 function, we examined the effect of a PX domain-mutated SNX2 that is defective in vesicle localization on EGFR trafficking. Mutant SNX2 markedly inhibited agonist-induced EGFR degradation, whereas internalization remained intact. In contrast, SNX1 PX domain mutants failed to effect EGFR degradation, whereas a SNX1 deletion mutant significantly inhibited receptor down-regulation. Interestingly, knockdown of SNX1 and SNX2 expression by RNA interference failed to alter agonist-induced EGFR down-regulation. Together, these findings suggest that both SNX1 and SNX2 are involved in regulating lysosomal sorting of internalized EGFR, but neither protein is essential for this process. These studies are the first to demonstrate a function for SNX2 in protein trafficking.

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