scholarly journals Caspase- and Serine Protease-dependent Apoptosis by the Death Domain of FADD in Normal Epithelial Cells

2003 ◽  
Vol 14 (1) ◽  
pp. 67-77 ◽  
Author(s):  
Jacqueline Thorburn ◽  
Laura M. Bender ◽  
Michael J. Morgan ◽  
Andrew Thorburn
Keyword(s):  
Epithelial Cells ◽  
Serine Protease ◽  
Death Domain ◽  
Cell Type ◽  
Normal Prostate ◽  
Effector Domain ◽  
Death Effector Domain ◽  
Prostate Epithelial Cells ◽  
Cell Type Specific ◽  
Death Effector

The adapter protein FADD consists of two protein interaction domains: a death domain and a death effector domain. The death domain binds to activated death receptors such as Fas, whereas the death effector domain binds to procaspase 8. An FADD mutant, which consists of only the death domain (FADD-DD), inhibits death receptor–induced apoptosis. FADD-DD can also activate a mechanistically distinct, cell type–specific apoptotic pathway that kills normal but not cancerous prostate epithelial cells. Here, we show that this apoptosis occurs through activation of caspases 9, 3, 6, and 7 and a serine protease. Simultaneous inhibition of caspases and serine proteases prevents FADD-DD–induced death. Inhibition of either pathway alone does not prevent cell death but does affect the morphology of the dying cells. Normal prostate epithelial cells require both the caspase and serine protease inhibitors to efficiently prevent apoptosis in response to TRAIL. In contrast, the serine protease inhibitor does not affect TRAIL-induced death in prostate tumor cells suggesting that the FADD-DD–dependent pathway can be activated by TRAIL. This apoptosis pathway is activated in a cell type–specific manner that is defective in cancer cells, suggesting that this pathway may be targeted during cancer development.

scholarly journals PEA-15 C-Terminal Tail Allosterically Modulates Death-Effector Domain Conformation and Facilitates Protein–Protein Interactions

2019 ◽  
Vol 20 (13) ◽  
pp. 3335
Author(s):  
Sergio L. Crespo-Flores ◽  
Andres Cabezas ◽  
Sherouk Hassan ◽  
Yufeng Wei
Keyword(s):  
Protein Interactions ◽  
De Novo ◽  
Free Form ◽  
Docking Site ◽  
Death Domain ◽  
Protein Protein Interactions ◽  
Effector Domain ◽  
Death Effector Domain ◽  
Signaling Complex ◽  
Death Effector

Phosphoprotein enriched in astrocytes, 15 kDa (PEA-15) exerts its regulatory roles on several critical cellular pathways through protein–protein interactions depending on its phosphorylation states. It can either inhibit the extracellular signal-regulated kinase (ERK) activities when it is dephosphorylated or block the assembly of death-inducing signaling complex (DISC) and the subsequent activation of apoptotic initiator, caspase-8, when it is phosphorylated. Due to the important roles of PEA-15 in regulating these pathways that lead to opposite cellular outcomes (cell proliferation vs. cell death), we proposed a phosphostasis (phosphorylation homeostasis) model, in which the phosphorylation states of the protein are vigorously controlled and regulated to maintain a delicate balance. The phosphostasis gives rise to the protective cellular functions of PEA-15 to preserve optimum cellular conditions. In this article, using advanced multidimensional nuclear magnetic resonance (NMR) techniques combined with a novel chemical shift (CS)-Rosetta algorithm for de novo protein structural determination, we report a novel conformation of PEA-15 death-effector domain (DED) upon interacting with ERK2. This new conformation is modulated by the irregularly structured C-terminal tail when it first recognizes and binds to ERK2 at the d-peptide recruitment site (DRS) in an allosteric manner, and is facilitated by the rearrangement of the surface electrostatic and hydrogen-bonding interactions on the DED. In this ERK2-bound conformation, three of the six helices (α2, α3, and α4) comprising the DED reorient substantially in comparison to the free-form structure, exposing key residues on the other three helices that directly interact with ERK2 at the DEF-docking site (docking site for ERK, FxF) and the activation loop. Additionally, we provide evidence that the phosphorylation of the C-terminal tail leads to a distinct conformation of DED, allowing efficient interactions with Fas-associated death domain (FADD) protein at the DISC. Our results substantiate the allosteric regulatory roles of the C-terminal tail in modulating DED conformation and facilitating protein–protein interactions of PEA-15.

scholarly journals Vanishin is a novel ubiquitinylated death-effector domain protein that blocks ERK activation

2005 ◽  
Vol 387 (2) ◽  
pp. 315-324 ◽  
Author(s):  
Runa SUR ◽  
Joe W. RAMOS
Keyword(s):  
Mitogen Activated Protein Kinase ◽  
Death Domain ◽  
Effector Domain ◽  
Erk Activation ◽  
Death Effector Domain ◽  
Mouse Tissues ◽  
Lysine Residues ◽  
Mitogen Activated Protein ◽  
Domain Protein ◽  
Death Effector

The ERK (extracellular-signal regulated-kinase)/MAPK (mitogen-activated protein kinase) pathway can regulate transcription, proliferation, migration and apoptosis. The small DED (death-effector domain) protein PEA-15 (phosphoprotein enriched in astrocytes-15) binds ERK and targets it to the cytoplasm. Other DED-containing proteins including cFLIP and DEDD can also regulate signal transduction events and transcription in addition to apoptosis. In the present study, we report the identification of a novel DED-containing protein called Vanishin. The amino acid sequence of Vanishin is closest in similarly to PEA-15 (61% identical). Vanishin mRNA is expressed in several mouse tissues and in both mouse and human cell lines. Interestingly, Vanishin is regulated by ubiquitinylation and subsequent degradation by the 26 S proteasome. The ubiquitinylation is complex and occurs at both the internal lysine residues and the N-terminus. We further show that Vanishin binds ERK/MAPK but not the DED proteins Fas-associated death domain, caspase 8 or PEA-15. Vanishin is present in both the nucleus and Golgi on overexpression and forces increased ERK accumulation in the nucleus in the absence of ERK stimulation. Moreover, Vanishin expression inhibits ERK activation and ERK-dependent transcription in cells, but does not alter MAPK/ERK activity. Therefore Vanishin is a novel regulator of ERK that is controlled by ubiquitinylation.

scholarly journals The expression and localization of V-ATPase and cytokeratin 5 during postnatal development of the pig epididymis

2020 ◽  
Vol 33 (7) ◽  
pp. 1077-1086 ◽  
Author(s):  
Yun-Jae Park ◽  
Ji-Hyuk Kim ◽  
Hack-Youn Kim ◽  
Hee-Bok Park ◽  
Juhui Choe ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Expression Patterns ◽  
Basal Cells ◽  
Cell Type ◽  
Clear Cells ◽  
Specific Distribution ◽  
Cytokeratin 5 ◽  
Cell Type Specific ◽  
Immunofluorescence Labeling ◽  
And Storage

Objective: We examined the localization and expression of H<sup>+ pumping vacuolar ATPase (V-ATPase) and cytokeratin 5 (KRT5) in the epididymis of pigs, expressed in clear and basal cells, respectively, during postnatal development.Methods: Epididymides were obtained from pigs at 1, 7, 21, 60, 120, and 180 days of age; we observed the localization and expression patterns of V-ATPase and KRT5 in the different regions of these organs, namely, the caput, corpus, and cauda. The differentiation of epididymal epithelial cells was determined by immunofluorescence labeling using cell-type-specific markers and observed using confocal microscopy.Results: At postnatal day 5 (PND5), the localization of clear cells commenced migration from the cauda toward the caput. Although at PND120, goblet-shaped clear cells were detected along the entire length of the epididymis, those labeled for V-ATPase had disappeared from the corpus to cauda and were maintained only in the caput epididymis in adult pigs. In contrast, whereas basal cells labeled for KRT5 were only present in the vas deferens at birth, they were detected in all regions of the epididymis at PND60. These cells were localized at the base of the epithelium; however, no basal cells characterized by luminally extending cell projections were observed in any of the adult epididymides examined.Conclusion: The differentiation of clear and basal cells progressively initiates in a retrograde manner from the cauda to the caput epididymis. The cell-type-specific distribution and localization of the epithelial cells play important roles in establishing a unique luminal environment for sperm maturation and storage in the pig epididymis.

Sign in / Sign up

Export Citation Format

Share Document