scholarly journals The Kinetics of Mannose 6-Phosphate Receptor Trafficking in the Endocytic Pathway in HEp-2 Cells: The Receptor Enters and Rapidly Leaves Multivesicular Endosomes without Accumulating in a Prelysosomal Compartment

1998 ◽  
Vol 9 (4) ◽  
pp. 809-816 ◽  
Author(s):  
Jennifer Hirst ◽  
Clare E. Futter ◽  
Colin R. Hopkins
Keyword(s):  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Growth Factor Receptor ◽  
Cell Types ◽  
Endocytic Pathway ◽  
Receptor Complexes ◽  
Epidermal Growth ◽  
Mannose 6 Phosphate ◽  
Golgi Network ◽  
Multivesicular Endosomes

We have previously shown that in HEp-2 cells, multivesicular bodies (MVBs) processing internalized epidermal growth factor–epidermal growth factor receptor complexes mature and fuse directly with lysosomes in which the complexes are degraded. The MVBs do not fuse with a prelysosomal compartment enriched in mannose 6-phosphate receptor (M6PR) as has been described in other cell types. Here we show that the cation-independent M6PR does not become enriched in the endocytic pathway en route to the lysosome, but if a pulse of M6PR or an M6PR ligand, cathepsin D, is followed, a significant fraction of these proteins are routed from the trans-Golgi to MVBs. Accumulation of M6PR does not occur because when the ligand dissociates, the receptor rapidly leaves the MVB. At steady state, most M6PR are distributed within the trans-Golgi andtrans-Golgi network and in vacuolar structures distributed in the peripheral cytoplasm. We suggest that these M6PR-rich vacuoles are on the return route from MVBs to thetrans-Golgi network and that a separate stable M6PR-rich compartment equivalent to the late endosome/prelysosome stage does not exist on the endosome–lysosome pathway in these cells.

Subfractionation of the endocytic pathway: isolation of compartments involved in the processing of internalised epidermal growth factor-receptor complexes

1989 ◽  
Vol 94 (4) ◽  
pp. 685-694
Author(s):  
C.E. Futter ◽  
C.R. Hopkins
Keyword(s):  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Egf Receptor ◽  
Biological Effects ◽  
Growth Factor Receptor ◽  
Endocytic Pathway ◽  
Receptor Complexes ◽  
Epidermal Growth ◽  
Endocytic Vesicles ◽  
Different Parts

The aim of the present study was to isolate different parts of the endocytic pathway in order to examine the role of epidermal growth factor (EGF)-receptor internalisation in mediating the biological effects of EGF. We have used an antibody to the transferrin receptor complexed with colloidal gold to modify the density of the endocytic compartments so that they can be purified by sucrose density centrifugation. Using this technique, we have been able to isolate a highly purified preparation of endocytic vesicles from H.Ep.2 cells that contain internalised EGF. By employing pulse—chase protocols, it is possible to isolate the different parts of the endocytic pathway and show that they are temporally distinct with regard to the processing of EGF. It should now be possible to examine interactions between the EGF receptor and intracellular substrates in different parts of the endocytic pathway.

scholarly journals Epidermal Growth Factor Receptor and Abl2 Kinase Regulate Distinct Steps of Human Papillomavirus 16 Endocytosis

2020 ◽  
Vol 94 (11) ◽  
Author(s):  
Carina Bannach ◽  
Pia Brinkert ◽  
Lena Kühling ◽  
Lilo Greune ◽  
M. Alexander Schmidt ◽  
...  
Keyword(s):  
Epidermal Growth Factor Receptor ◽  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Growth Factor Receptor ◽  
Endocytic Pathway ◽  
Egfr Signaling ◽  
Endocytic Vesicle ◽  
Human Papillomavirus 16 ◽  
Epidermal Growth

ABSTRACT Human papillomavirus 16 (HPV16), the leading cause of cervical cancer, exploits a novel endocytic pathway during host cell entry. This mechanism shares many requirements with macropinocytosis but differs in the mode of vesicle formation. Previous work indicated a role of the epidermal growth factor receptor (EGFR) in HPV16 endocytosis. However, the functional outcome of EGFR signaling and its downstream targets during HPV16 uptake are not well characterized. Here, we analyzed the functional importance of signal transduction via EGFR and its downstream effectors for endocytosis of HPV16. Our findings indicate two phases of EGFR signaling as follows: a—likely dispensable—transient activation with or shortly after cell binding and signaling required throughout the process of asynchronous internalization of HPV16. Interestingly, EGFR inhibition interfered with virus internalization and strongly reduced the number of endocytic pits, suggesting a role for EGFR signaling in the induction of HPV16 endocytosis. Moreover, we identified the Src-related kinase Abl2 as a novel regulator of virus uptake. Inhibition of Abl2 resulted in an accumulation of misshaped endocytic pits, indicating Abl2’s importance for endocytic vesicle maturation. Since Abl2 rather than Src, a regulator of membrane ruffling during macropinocytosis, mediated downstream signaling of EGFR, we propose that the selective effector targeting downstream of EGFR determines whether HPV16 endocytosis or macropinocytosis is induced. IMPORTANCE Human papillomaviruses are small, nonenveloped DNA viruses that infect skin and mucosa. The so-called high-risk HPVs (e.g., HPV16, HPV18, HPV31) have transforming potential and are associated with various anogenital and oropharyngeal tumors. These viruses enter host cells by a novel endocytic pathway with unknown cellular function. To date, it is unclear how endocytic vesicle formation occurs mechanistically. Here, we addressed the role of epidermal growth factor receptor signaling, which has previously been implicated in HPV16 endocytosis and identified the kinase Abl2 as a novel regulator of virus uptake. Since other viruses, such as influenza A virus and lymphocytic choriomeningitis virus, possibly make use of related mechanisms, our findings shed light on fundamental strategies of virus entry and may in turn help to develop new host cell-targeted antiviral strategies.

scholarly journals Functional state of the epidermal growth factor-receptor complexes during their internalization in A-431 cells.

1990 ◽  
Vol 10 (9) ◽  
pp. 5011-5014 ◽  
Author(s):  
A Nesterov ◽  
G Reshetnikova ◽  
N Vinogradova ◽  
N Nikolsky
Keyword(s):  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Functional State ◽  
Egf Receptor ◽  
Polyclonal Antibodies ◽  
Growth Factor Receptor ◽  
Receptor Kinase ◽  
Peptide Substrate ◽  
Receptor Complexes ◽  
Epidermal Growth

Functional state of internalized epidermal growth factor (EGF) receptor in A-431 cells has been studied. The use of photoaffinity [125I]EGF derivative allowed us to establish that inside the cell the EGF retains its connection with the receptor. With the help of polyclonal antibodies to phosphotyrosine, it has been shown that EGF-receptor complexes maintain their phosphorylated state during internalization. The internalized EGF receptor kinase as well as that localized in the plasma membrane appeared to be able to phosphorylate synthetic peptide substrate introduced into the cell.

Signaling from germ cells mediated by therhomboidhomologstetorganizes encapsulation by somatic support cells

Development ◽  
2002 ◽  
Vol 129 (19) ◽  
pp. 4523-4534 ◽  
Author(s):  
Cordula Schulz ◽  
Cricket G. Wood ◽  
D. Leanne Jones ◽  
Salli I. Tazuke ◽  
Margaret T. Fuller
Keyword(s):  
Epidermal Growth Factor Receptor ◽  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Germ Cells ◽  
Somatic Cells ◽  
Growth Factor Receptor ◽  
Cell Types ◽  
Germ Cell Differentiation ◽  
Epidermal Growth ◽  
Set Up

Germ cells normally differentiate in the context of encapsulating somatic cells. However, the mechanisms that set up the special relationship between germ cells and somatic support cells and the signals that mediate the crucial communications between the two cell types are poorly understood. We show that interactions between germ cells and somatic support cells in Drosophila depend on wild-type function of the stet gene. In males, stet acts in germ cells to allow their encapsulation by somatic cyst cells and is required for germ cell differentiation. In females, stet function allows inner sheath cells to enclose early germ cells correctly at the tip of the germarium. stet encodes a homolog of rhomboid, a component of the epidermal growth factor receptor signaling pathway involved in ligand activation in the signaling cell. The stet mutant phenotype suggests that stet facilitates signaling from germ cells to the epidermal growth factor receptor on somatic cells, resulting in the encapsulation of germ cells by somatic support cells. The micro-environment provided by the surrounding somatic cells may, in turn, regulate differentiation of the germ cells they enclose.

scholarly journals Positive and negative tissue-specific signaling by a nematode epidermal growth factor receptor.

1997 ◽  
Vol 8 (5) ◽  
pp. 779-793 ◽  
Author(s):  
G M Lesa ◽  
P W Sternberg
Keyword(s):  
Epidermal Growth Factor Receptor ◽  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Binding Sites ◽  
Growth Factor Receptor ◽  
Cell Types ◽  
Negative Regulation ◽  
Tissue Specific ◽  
Epidermal Growth

The major determinants of receptor tissue tyrosine kinase (RTK) signaling specificity have been proposed to be Src homology 2 (SH2) binding sites, phosphotyrosine-containing oligopeptides in the cytoplasmic domain of the receptor. The Caenorhabditis elegans epidermal growth factor receptor homologue LET-23 has multiple functions during development and has eight potential SH2-binding sites in a region carboxyl terminal to its kinase domain. By analyzing transgenic nematodes for three distinct LET-23 functions, we show that six of eight potential sites function in vivo and that they are required for most, but not all, of LET-23 activity. A single site is necessary and sufficient to promote wild-type fertility. Three other sites activate the RAS pathway and are involved only in viability and vulval differentiation. A fifth site is promiscuous and can mediate all three LET-23 functions. An additional site mediates tissue-specific negative regulation. Putative SH2 binding sites are thus key effectors of both cell-specific and negative regulation in an intact organism. We suggest two distinct mechanisms for tissue-specific RTK-mediated signaling. A positive mechanism would promote RTK function through effectors present only in certain cell types. A negative mechanism would inhibit RTK function through tissue-specific negative regulators.

scholarly journals Eps15 Is Recruited to the Plasma Membrane upon Epidermal Growth Factor Receptor Activation and Localizes to Components of the Endocytic Pathway during Receptor Internalization

1999 ◽  
Vol 10 (2) ◽  
pp. 417-434 ◽  
Author(s):  
Maria Rosaria Torrisi ◽  
Lavinia Vittoria Lotti ◽  
Francesca Belleudi ◽  
Roberto Gradini ◽  
Anna Elisabetta Salcini ◽  
...  
Keyword(s):  
Epidermal Growth Factor Receptor ◽  
Plasma Membrane ◽  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Growth Factor Receptor ◽  
Adaptor Protein ◽  
Receptor Activation ◽  
Endocytic Pathway ◽  
Receptor Internalization ◽  
Epidermal Growth

Eps15 is a substrate for the tyrosine kinase of the epidermal growth factor receptor (EGFR) and is characterized by the presence of a novel protein:protein interaction domain, the EH domain. Eps15 also stably binds the clathrin adaptor protein complex AP-2. Previous work demonstrated an essential role for eps15 in receptor-mediated endocytosis. In this study we show that, upon activation of the EGFR kinase, eps15 undergoes dramatic relocalization consisting of 1) initial relocalization to the plasma membrane and 2) subsequent colocalization with the EGFR in various intracellular compartments of the endocytic pathway, with the notable exclusion of coated vesicles. Relocalization of eps15 is independent of its binding to the EGFR or of binding of the receptor to AP-2. Furthermore, eps15 appears to undergo tyrosine phosphorylation both at the plasma membrane and in a nocodazole-sensitive compartment, suggesting sustained phosphorylation in endocytic compartments. Our results are consistent with a model in which eps15 undergoes cycles of association:dissociation with membranes and suggest multiple roles for this protein in the endocytic pathway.

Recycling of epidermal growth factor-receptor complexes in A431 cells

1989 ◽  
Vol 1011 (1) ◽  
pp. 88-96 ◽  
Author(s):  
Alexander Sorkin ◽  
Elena Kornilova ◽  
Lyudmila Teslenko ◽  
Andrew Sorokin ◽  
Nikolai Nikolsky
Keyword(s):  
Epidermal Growth Factor Receptor ◽  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Growth Factor Receptor ◽  
A431 Cells ◽  
Receptor Complexes ◽  
Epidermal Growth

scholarly journals Functional Roles of SPINK1 in Cancers

2021 ◽  
Vol 22 (8) ◽  
pp. 3814
Author(s):  
Tsung-Chieh Lin
Keyword(s):  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Cancer Progression ◽  
Biological Effects ◽  
Growth Factor Receptor ◽  
Clinical Information ◽  
Structural Similarity ◽  
Cell Types ◽  
Cancer Proliferation ◽  
Epidermal Growth

Serine Peptidase Inhibitor Kazal Type 1 (SPINK1) is a secreted protein known as a protease inhibitor of trypsin in the pancreas. However, emerging evidence shows its function in promoting cancer progression in various types of cancer. SPINK1 modulated tumor malignancies and induced the activation of the downstream signaling of epidermal growth factor receptor (EGFR) in cancer cells, due to the structural similarity with epidermal growth factor (EGF). The discoverable SPINK1 somatic mutations, expressional signatures, and prognostic significances in various types of cancer have attracted attention as a cancer biomarker in clinical applications. Emerging findings further clarify the direct and indirect biological effects of SPINK1 in regulating cancer proliferation, metastasis, drug resistance, transdifferentiation, and cancer stemness, warranting the exploration of the SPINK1-mediated molecular mechanism to identify a therapeutic strategy. In this review article, we first integrate the transcriptomic data of different types of cancer with clinical information and recent findings of SPINK1-mediated malignant phenotypes. In addition, a comprehensive summary of SPINK1 expression in a pan-cancer panel and individual cell types of specific organs at the single-cell level is presented to indicate the potential sites of tumorigenesis, which has not yet been reported. This review aims to shed light on the roles of SPINK1 in cancer and provide guidance and potential directions for scientists in this field.

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