scholarly journals The Mouse SKD1, a Homologue of Yeast Vps4p, Is Required for Normal Endosomal Trafficking and Morphology in Mammalian Cells

2000 ◽  
Vol 11 (2) ◽  
pp. 747-763 ◽  
Author(s):  
Tamotsu Yoshimori ◽  
Fumi Yamagata ◽  
Akitsugu Yamamoto ◽  
Noboru Mizushima ◽  
Yukiko Kabeya ◽  
...  
Keyword(s):  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Mammalian Cells ◽  
Secretory Pathway ◽  
Density Lipoprotein ◽  
Dominant Negative ◽  
Mutant Protein ◽  
Endosomal Trafficking ◽  
Dominant Negative Mutation ◽  
Epidermal Growth

The mouse SKD1 is an AAA-type ATPase homologous to the yeast Vps4p implicated in transport from endosomes to the vacuole. To elucidate a possible role of SKD1 in mammalian endocytosis, we generated a mutant SKD1, harboring a mutation (E235Q) that is equivalent to the dominant negative mutation (E233Q) in Vps4p. Overexpression of the mutant SKD1 in cultured mammalian cells caused defect in uptake of transferrin and low-density lipoprotein. This was due to loss of their receptors from the cell surface. The decrease of the surface transferrin receptor (TfR) was correlated with expression levels of the mutant protein. The mutant protein displayed a perinuclear punctate distribution in contrast to a diffuse pattern of the wild-type SKD1. TfR, the lysosomal protein lamp-1, endocytosed dextran, and epidermal growth factor but not markers for the secretory pathway were accumulated in the mutant SKD1–localized compartments. Degradation of epidermal growth factor was inhibited. Electron microscopy revealed that the compartments were exaggerated multivesicular vacuoles with numerous tubulo-vesicular extensions containing TfR and endocytosed horseradish peroxidase. The early endosome antigen EEA1 was also redistributed to these aberrant membranes. Taken together, our findings suggest that SKD1 regulates morphology of endosomes and membrane traffic through them.

scholarly journals A dominant negative mutation suppresses the function of normal epidermal growth factor receptors by heterodimerization.

1991 ◽  
Vol 11 (3) ◽  
pp. 1454-1463 ◽  
Author(s):  
O Kashles ◽  
Y Yarden ◽  
R Fischer ◽  
A Ullrich ◽  
J Schlessinger
Keyword(s):  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Living Cells ◽  
Dominant Negative ◽  
Egf Receptors ◽  
Wild Type ◽  
Dominant Negative Mutation ◽  
Epidermal Growth ◽  
Mutant Receptors ◽  
In Cells

Recent studies provide evidence that defective receptors can function as a dominant negative mutation suppressing the action of wild-type receptors. This causes various diminished responses in cell culture and developmental disorders in murine embryogenesis. Here, we describe a model system and a potential mechanism underlying the dominant suppressing response caused by defective epidermal growth factor (EGF) receptors. We used cultured 3T3 cells coexpressing human wild-type receptors and an inactive deletion mutant lacking most of the cytoplasmic domain. When expressed alone, EGF was able to stimulate the dimerization of either wild-type or mutant receptors in living cells as revealed by chemical covalent cross-linking experiments. In response to EGF, heterodimers and homodimers of wild-type and mutant receptors were observed in cells coexpressing both receptor species. However, only homodimers of wild-type EGF receptors underwent EGF-induced tyrosine autophosphorylation in living cells. These results indicate that the integrity of both receptor moieties within receptor dimers is essential for kinase activation and autophosphorylation. Moreover, the presence of mutant receptors in cells expressing wild-type receptors diminished the number of high-affinity binding sites for EGF, reduced the rate of receptor endocytosis and degradation, and diminished biological signalling via EGF receptors. We propose that heterodimerization with defective EGF receptors functions as a dominant negative mutation suppressing the activation and response of normal receptors by formation of unproductive heterodimers.

A dominant negative mutation suppresses the function of normal epidermal growth factor receptors by heterodimerization

1991 ◽  
Vol 11 (3) ◽  
pp. 1454-1463
Author(s):  
O Kashles ◽  
Y Yarden ◽  
R Fischer ◽  
A Ullrich ◽  
J Schlessinger
Keyword(s):  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Living Cells ◽  
Dominant Negative ◽  
Egf Receptors ◽  
Wild Type ◽  
Dominant Negative Mutation ◽  
Epidermal Growth ◽  
Mutant Receptors ◽  
In Cells

Recent studies provide evidence that defective receptors can function as a dominant negative mutation suppressing the action of wild-type receptors. This causes various diminished responses in cell culture and developmental disorders in murine embryogenesis. Here, we describe a model system and a potential mechanism underlying the dominant suppressing response caused by defective epidermal growth factor (EGF) receptors. We used cultured 3T3 cells coexpressing human wild-type receptors and an inactive deletion mutant lacking most of the cytoplasmic domain. When expressed alone, EGF was able to stimulate the dimerization of either wild-type or mutant receptors in living cells as revealed by chemical covalent cross-linking experiments. In response to EGF, heterodimers and homodimers of wild-type and mutant receptors were observed in cells coexpressing both receptor species. However, only homodimers of wild-type EGF receptors underwent EGF-induced tyrosine autophosphorylation in living cells. These results indicate that the integrity of both receptor moieties within receptor dimers is essential for kinase activation and autophosphorylation. Moreover, the presence of mutant receptors in cells expressing wild-type receptors diminished the number of high-affinity binding sites for EGF, reduced the rate of receptor endocytosis and degradation, and diminished biological signalling via EGF receptors. We propose that heterodimerization with defective EGF receptors functions as a dominant negative mutation suppressing the activation and response of normal receptors by formation of unproductive heterodimers.

An epidermal growth factor receptor/ret chimera generates mitogenic and transforming signals: evidence for a ret-specific signaling pathway

1994 ◽  
Vol 14 (1) ◽  
pp. 663-675
Author(s):  
M Santoro ◽  
W T Wong ◽  
P Aroca ◽  
E Santos ◽  
B Matoskova ◽  
...  
Keyword(s):  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Tyrosine Kinases ◽  
Mammalian Cells ◽  
Egf Receptor ◽  
Biological Effects ◽  
Ectopic Expression ◽  
Growth Factor Receptor ◽  
Dependent Signal ◽  
Epidermal Growth

A chimeric expression vector which encoded for a molecule encompassing the extracellular domain of the epidermal growth factor (EGF) receptor (EGFR) and the intracellular domain of the ret kinase (EGFR/ret chimera) was generated. Upon ectopic expression in mammalian cells, the EGFR/ret chimera was correctly synthesized and transported to the cell surface, where it was shown capable of binding EGF and transducing an EGF-dependent signal intracellularly. Thus, the EGFR/ret chimera allows us to study the biological effects and biochemical activities of the ret kinase under controlled conditions of activation. Comparative analysis of the growth-promoting activity of the EGFR/ret chimera expressed in fibroblastic or hematopoietic cells revealed a biological phenotype clearly distinguishable from that of the EGFR, indicating that the two kinases couple with mitogenic pathways which are different to some extent. Analysis of biochemical pathways implicated in the transduction of mitogenic signals also evidenced significant differences between the ret kinase and other receptor tyrosine kinases. Thus, the sum of our results indicates the existence of a ret-specific pathway of mitogenic signaling.

Ultraviolet-B (290 – 320 nm)-Irradiation Inhibits Epidermal Growth-Factor Binding to Mammalian Cells

1989 ◽  
Vol 92 (4) ◽  
pp. 617-622 ◽  
Author(s):  
Mary S. Matsui ◽  
Leopold Laufer ◽  
Sara Scheide ◽  
Vincent DeLeo
Keyword(s):  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Mammalian Cells ◽  
Ultraviolet B ◽  
Factor Binding ◽  
Epidermal Growth

scholarly journals Localization of Phospholipase D1 to Caveolin-enriched Membrane via Palmitoylation: Implications for Epidermal Growth Factor Signaling

2002 ◽  
Vol 13 (11) ◽  
pp. 3976-3988 ◽  
Author(s):  
Jung Min Han ◽  
Yong Kim ◽  
Jun Sung Lee ◽  
Chang Sup Lee ◽  
Byoung Dae Lee ◽  
...  
Keyword(s):  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Egf Receptor ◽  
Point Mutations ◽  
Dominant Negative ◽  
Growth Factor Signaling ◽  
Wild Type ◽  
Caveolin 1 ◽  
Epidermal Growth ◽  
Egf Signaling

Phospholipase D (PLD) has been suggested to mediate epidermal growth factor (EGF) signaling. However, the molecular mechanism of EGF-induced PLD activation has not yet been elucidated. We investigated the importance of the phosphorylation and compartmentalization of PLD1 in EGF signaling. EGF treatment of COS-7 cells transiently expressing PLD1 stimulated PLD1 activity and induced PLD1 phosphorylation. The EGF-induced phosphorylation of threonine147 was completely blocked and the activity of PLD1 attenuated by point mutations (S2A/T147A/S561A) of PLD1 phosphorylation sites. The expression of a dominant negative PKCα mutant by adenovirus-mediated gene transfer greatly inhibited the phosphorylation and activation of PLD1 induced by EGF in PLD1-transfected COS-7 cells. EGF-induced PLD1 phosphorylation occurred primarily in the caveolin-enriched membrane (CEM) fraction, and the kinetics of PLD1 phosphorylation in the CEM were strongly correlated with PLD1 phosphorylation in the total membrane. Interestingly, EGF-induced PLD1 phosphorylation and activation and the coimmunoprecipitation of PLD1 with caveolin-1 and the EGF receptor in the CEM were significantly attenuated in the palmitoylation-deficient C240S/C241S mutant, which did not localize to the CEM. Immunocytochemical analysis revealed that wild-type PLD1 colocalized with caveolin-1 and the EGF receptor and that phosphorylated PLD1 was localized exclusively in the plasma membrane, although some PLD1 was also detected in vesicular structures. Transfection of wild-type PLD1 but not of C240S/C241S mutant increased EGF-induced raf-1 translocation to the CEM and ERK phosphorylation. This study shows, for the first time, that EGF-induced PLD1 phosphorylation and activation occur in the CEM and that the correct localization of PLD1 to the CEM via palmitoylation is critical for EGF signaling.

scholarly journals Laminin γ3 Chain Binds to Nidogen and Is Located in Murine Basement Membranes

2005 ◽  
Vol 280 (23) ◽  
pp. 22146-22153 ◽  
Author(s):  
Nikolaus Gersdorff ◽  
Eddie Kohfeldt ◽  
Takako Sasaki ◽  
Rupert Timpl ◽  
Nicolai Miosge
Keyword(s):  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Self Assembly ◽  
Mammalian Cells ◽  
Polyclonal Antibodies ◽  
Basement Membranes ◽  
Electron Microscopic ◽  
Immunogold Staining ◽  
Adult Mice ◽  
Epidermal Growth

Recently a novel laminin γ3 chain was identified in mouse and human and shown to have the same modular structure as the laminin γ1 chain. We expressed two fragments of the γ3 chain in mammalian cells recombinantly. The first, domain VI/V, consisting of laminin N-terminal (domain VI) and four laminin-type epidermal growth factor-like (domain V) and laminin N-terminal modules, was shown to be essential for self-assembly of laminins. The other was domain III3–5, which consists of three laminin-type epidermal growth factor-like modules and is predicted to bind to nidogens. The γ3 VI/V fragment was a poor inhibitor for laminin-1 polymerization as was the β2 VI/V fragment. The γ3 III3–5 fragment bound to nidogen-1 and nidogen-2 with lower affinity than the γ1 III3–5 fragment. These data suggested that laminins containing the γ3 chain may assemble networks independent of other laminins. Polyclonal antibodies raised against γ3 VI/V and γ3 III3–5 showed no cross-reaction with homologous fragments from the γ1 and γ2 chains of laminin and allowed the establishment of γ chain-specific radioimmunoassays and light and electron microscopic immunostaining of tissues. This demonstrated a 20–100-fold lower content of the γ3 chain compared with the γ1 chain in various tissue extracts of adult mice. The expression of γ3 chain was highly tissue-specific. In contrast to earlier assumptions, the antibodies against the γ3 chain showed light microscopic staining exclusively in basement membrane zones of adult and embryonic tissues, such as the brain, kidney, skin, muscle, and testis. Ultrastructural immunogold staining localized the γ3 chain to basement membranes of these tissues.

scholarly journals Regulation of EGFR Endocytosis by CBL During Mitosis

Cells ◽  
2018 ◽  
Vol 7 (12) ◽  
pp. 257 ◽  
Author(s):  
Ping Wee ◽  
Zhixiang Wang
Keyword(s):  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Cell Signaling ◽  
Binding Site ◽  
Egf Receptor ◽  
Dominant Negative ◽  
Low Doses ◽  
Interphase Cells ◽  
Epidermal Growth ◽  
Mcf 7

The overactivation of epidermal growth factor (EGF) receptor (EGFR) is implicated in various cancers. Endocytosis plays an important role in EGFR-mediated cell signaling. We previously found that EGFR endocytosis during mitosis is mediated differently from interphase. While the regulation of EGFR endocytosis in interphase is well understood, little is known regarding the regulation of EGFR endocytosis during mitosis. Here, we found that contrary to interphase cells, mitotic EGFR endocytosis is more reliant on the activation of the E3 ligase CBL. By transfecting HeLa, MCF-7, and 293T cells with CBL siRNA or dominant-negative 70z-CBL, we found that at high EGF doses, CBL is required for EGFR endocytosis in mitotic cells, but not in interphase cells. In addition, the endocytosis of mutant EGFR Y1045F-YFP (mutation at the direct CBL binding site) is strongly delayed. The endocytosis of truncated EGFR Δ1044-YFP that does not bind to CBL is completely inhibited in mitosis. Moreover, EGF induces stronger ubiquitination of mitotic EGFR than interphase EGFR, and mitotic EGFR is trafficked to lysosomes for degradation. Furthermore, we showed that, different from interphase, low doses of EGF still stimulate EGFR endocytosis by non-clathrin mediated endocytosis (NCE) in mitosis. Contrary to interphase, CBL and the CBL-binding regions of EGFR are required for mitotic EGFR endocytosis at low doses. This is due to the mitotic ubiquitination of the EGFR even at low EGF doses. We conclude that mitotic EGFR endocytosis exclusively proceeds through CBL-mediated NCE.

The First Epidermal Growth Factor-like Domain of the Low-Density Lipoprotein Receptor Contains a Noncanonical Calcium Binding Site†

Biochemistry ◽  
2001 ◽  
Vol 40 (8) ◽  
pp. 2555-2563 ◽  
Author(s):  
Steven Malby ◽  
Ruth Pickering ◽  
Saurabh Saha ◽  
Rachel Smallridge ◽  
Sara Linse ◽  
...  
Keyword(s):  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Calcium Binding ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Low Density ◽  
Lipoprotein Receptor ◽  
Calcium Binding Site ◽  
Density Lipoprotein Receptor ◽  
Epidermal Growth

Effect of Dominant-Negative Epidermal Growth Factor Receptors on Cardiomyocyte Hypertrophy

2006 ◽  
Vol 26 (5-6) ◽  
pp. 659-677 ◽  
Author(s):  
HSIU-WEN CHAN ◽  
ANNA JENKINS ◽  
LUISA PIPOLO ◽  
ROSS D. HANNAN ◽  
WALTER G. THOMAS ◽  
...  
Keyword(s):  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Growth Factor Receptors ◽  
Dominant Negative ◽  
Cardiomyocyte Hypertrophy ◽  
Epidermal Growth Factor Receptors ◽  
Epidermal Growth
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