scholarly journals Casein Kinase 1 Is a Novel Negative Regulator of E-Cadherin-Based Cell-Cell Contacts

2007 ◽  
Vol 27 (10) ◽  
pp. 3804-3816 ◽  
Author(s):  
Sophie Dupre-Crochet ◽  
Angélica Figueroa ◽  
Catherine Hogan ◽  
Emma C. Ferber ◽  
Carl Uli Bialucha ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Phosphorylation Site ◽  
Specific Inhibitor ◽  
Casein Kinase ◽  
Negative Regulator ◽  
Casein Kinase 1 ◽  
Cell Contacts ◽  
E Cadherin ◽  
Cell Cell

ABSTRACT Cadherins are the most crucial membrane proteins for the formation of tight and compact cell-cell contacts. Cadherin-based cell-cell adhesions are dynamically established and/or disrupted during various physiological and pathological processes. However, the molecular mechanisms that regulate cell-cell contacts are not fully understood. In this paper, we report a novel functional role of casein kinase 1 (CK1) in the regulation of cell-cell contacts. Firstly, we observed that IC261, a specific inhibitor of CK1, stabilizes cadherin-based cell-cell contacts, whereas the overexpression of CK1 disrupts them. CK1 colocalizes with E-cadherin and phosphorylates the cytoplasmic domain of E-cadherin in vitro and in a cell culture system. We show that the major CK1 phosphorylation site of E-cadherin is serine 846, a highly conserved residue between classical cadherins. Constitutively phosphorylated E-cadherin (S846D) is unable to localize at cell-cell contacts and has decreased adhesive activity. Furthermore, phosphorylated E-cadherin (S846D) has weaker interactions with β-catenin and is internalized more efficiently than wild-type E-cadherin. These data indicate that CK1 is a novel negative regulator of cadherin-based cell-cell contacts.

scholarly journals Casein kinase-1γ1 and 3 stimulate tumor necrosis factor-induced necroptosis through RIPK3

2019 ◽  
Vol 10 (12) ◽  
Author(s):  
Song-Yi Lee ◽  
Hyunjoo Kim ◽  
Cathena Meiling Li ◽  
Jaemin Kang ◽  
Ayaz Najafov ◽  
...  
Keyword(s):  
Ectopic Expression ◽  
Specific Inhibitor ◽  
Casein Kinase ◽  
In Vitro Assays ◽  
Serine Threonine Kinase ◽  
Casein Kinase 1 ◽  
Threonine Kinase ◽  
Necrosis Factor

AbstractUpon necroptosis activation, receptor interacting serine/threonine kinase (RIPK)1 and RIPK3 form a necrosome complex with pseudokinase mixed lineage kinase-like (MLKL). Although protein phosphorylation is a key event for RIPK1 and RIPK3 activation in response to a necroptosis signal, relatively little is known about other factors that might regulate the activity of these kinases or necrosome formation. Through a gain-of-function screen with 546 kinases and 127 phosphatases, we identified casein kinase 1 gamma (CK1γ) as a candidate necroptosis-promoting factor. Here, we show that the decreased activity or amounts of CK1γ1 and CK1γ3, either by treatment with a chemical inhibitor or knockdown in cells, reduced TNFα-induced necroptosis. Conversely, ectopic expression of CK1γ1 or CK1γ3 exacerbated necroptosis, but not apoptosis. Similar to RIPK1 and RIPK3, CK1γ1 was also cleaved at Asp343 by caspase-8 during apoptosis. CK1γ1 and CK1γ3 formed a protein complex and were recruited to the necrosome harboring RIPK1, RIPK3 and MLKL. In particular, an autophosphorylated form of CK1γ3 at Ser344/345 was detected in the necrosome and was required to mediate the necroptosis. In addition, in vitro assays with purified proteins showed that CK1γ phosphorylated RIPK3, affecting its activity, and in vivo assays showed that the CK1γ-specific inhibitor Gi prevented abrupt death in mice with hypothermia in a model of TNFα-induced systemic inflammatory response syndrome. Collectively, these data suggest that CK1γ1 and CK1γ3 are required for TNFα-induced necroptosis likely by regulating RIPK3.

scholarly journals N-Cadherin Regulates the Odontogenic Differentiation of Dental Pulp Stem Cells via β-Catenin Activity

2021 ◽  
Vol 9 ◽  
Author(s):  
Zilong Deng ◽  
Wenjuan Yan ◽  
Xingzhu Dai ◽  
Ming Chen ◽  
Qian Qu ◽  
...  
Keyword(s):  
Stem Cells ◽  
Cell Fate ◽  
Dental Pulp ◽  
Specific Inhibitor ◽  
Negative Regulator ◽  
Pulp Regeneration ◽  
Odontogenic Differentiation ◽  
Cell Cell

Dental pulp stem cell (DPSC) transplantation has shown new prospects in dental pulp regeneration, and is of great significance in the treatment of pulpitis and pulp necrosis. The fate and regenerative potential of stem cells are dependent, to a great extent, on their microenvironment, which is composed of various tissue components, cell populations, and soluble factors. N-cadherin-mediated cell–cell interaction has been implicated as an important factor in controlling the cell-fate commitment of mesenchymal stem cells. In this study, the effect of N-cadherin on odontogenic differentiation of DPSCs and the potential underlying mechanisms, both in vitro and in vivo, was investigated using a cell culture model and a subcutaneous transplantation mouse model. It was found that the expression of N-cadherin was reversely related to the expression of odontogenic markers (dentin sialophosphoprotein, DSPP, and runt-related transcription factor 2, Runx2) during the differentiation process of DPSCs. Specific shRNA-mediated knockdown of N-cadherin expression in DPSCs significantly increased the expression of DSPP and Runx2, alkaline phosphatase (ALP) activity, and the formation of mineralized nodules. Notably, N-cadherin silencing promoted nucleus translocation and accumulation of β-catenin. Inhibition of β-catenin by a specific inhibitor XAV939, reversed the facilitating effects of N-cadherin downregulation on odontogenic differentiation of DPSCs. In addition, knockdown of N-cadherin promoted the formation of odontoblast-like cells and collagenous matrix in β-tricalcium phosphate/DPSCs composites transplanted into mice. In conclusion, N-cadherin acted as a negative regulator via regulating β-catenin activity during odontogenic differentiation of DPSCs. These data may help to guide DPSC behavior by tuning the N-cadherin-mediated cell–cell interactions, with implications for pulp regeneration.

scholarly journals Signal Transducer and Activator of Transcription 3 (STAT3) Suppresses STAT1/Interferon Signaling Pathway and Inflammation in Senescent Preadipocytes

Antioxidants ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 334
Author(s):  
Aisha Y. Madani ◽  
Yasser Majeed ◽  
Houari B. Abdesselem ◽  
Maha V. Agha ◽  
Muneera Vakayil ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Molecular Mechanisms ◽  
Adenosine Monophosphate ◽  
Human Adipose Tissue ◽  
Premature Aging ◽  
Guanosine Monophosphate ◽  
Negative Regulator ◽  
Signal Transducer ◽  
Interferon Signaling

Obesity promotes premature aging and dysfunction of white adipose tissue (WAT) through the accumulation of cellular senescence. The senescent cells burden in WAT has been linked to inflammation, insulin-resistance (IR), and type 2 diabetes (T2D). There is limited knowledge about molecular mechanisms that sustain inflammation in obese states. Here, we describe a robust and physiologically relevant in vitro system to trigger senescence in mouse 3T3-L1 preadipocytes. By employing transcriptomics analyses, we discovered up-regulation of key pro-inflammatory molecules and activation of interferon/signal transducer and activator of transcription (STAT)1/3 signaling in senescent preadipocytes, and expression of downstream targets was induced in epididymal WAT of obese mice, and obese human adipose tissue. To test the relevance of STAT1/3 signaling to preadipocyte senescence, we used Clustered Regularly Interspaced Short Palindromic Repeats/CRISPR associated protein 9 (CRISPR/Cas9) technology to delete STAT1/3 and discovered that STAT1 promoted growth arrest and cooperated with cyclic Guanosine Monophosphate-Adenosine Monophosphate (GMP-AMP) synthase-stimulator of interferon genes (cGAS-STING) to drive the expression of interferon β (IFNβ), C-X-C motif chemokine ligand 10 (CXCL10), and interferon signaling-related genes. In contrast, we discovered that STAT3 was a negative regulator of STAT1/cGAS-STING signaling—it suppressed senescence and inflammation. These data provide insights into how STAT1/STAT3 signaling coordinates senescence and inflammation through functional interactions with the cGAS/STING pathway.

scholarly journals A molecular mechanism directly linking E-cadherin adhesion to initiation of epithelial cell surface polarity

2007 ◽  
Vol 178 (2) ◽  
pp. 323-335 ◽  
Author(s):  
Lene N. Nejsum ◽  
W. James Nelson
Keyword(s):  
Cell Adhesion ◽  
Epithelial Cell ◽  
Cell Surface ◽  
Basolateral Membrane ◽  
Surface Polarity ◽  
Cell Contacts ◽  
Protein Receptors ◽  
Epithelial Cell Surface ◽  
E Cadherin ◽  
Cell Cell

Mechanisms involved in maintaining plasma membrane domains in fully polarized epithelial cells are known, but when and how directed protein sorting and trafficking occur to initiate cell surface polarity are not. We tested whether establishment of the basolateral membrane domain and E-cadherin–mediated epithelial cell–cell adhesion are mechanistically linked. We show that the basolateral membrane aquaporin (AQP)-3, but not the equivalent apical membrane AQP5, is delivered in post-Golgi structures directly to forming cell–cell contacts where it co-accumulates precisely with E-cadherin. Functional disruption of individual components of a putative lateral targeting patch (e.g., microtubules, the exocyst, and soluble N-ethylmaleimide–sensitive factor attachment protein receptors) did not inhibit cell–cell adhesion or colocalization of the other components with E-cadherin, but each blocked AQP3 delivery to forming cell–cell contacts. Thus, components of the lateral targeting patch localize independently of each other to cell–cell contacts but collectively function as a holocomplex to specify basolateral vesicle delivery to nascent cell–cell contacts and immediately initiate cell surface polarity.

scholarly journals CNPY4 inhibits the Hedgehog pathway by modulating membrane sterol lipids

2021 ◽  
Author(s):  
Megan Lo ◽  
Amnon Sharir ◽  
Michael D Paul ◽  
Hayarpi Torosyan ◽  
Christopher Agnew ◽  
...  
Keyword(s):  
Signal Transduction ◽  
Primary Cilia ◽  
Molecular Mechanisms ◽  
Negative Regulator ◽  
Membrane Composition ◽  
Hh Signaling ◽  
Pathway Regulation ◽  
Patched 1 ◽  
Cancer Signal Transduction

The Hedgehog (HH) pathway is critical for development and adult tissue homeostasis. Aberrant HH signaling can cause congenital malformations, such as digit anomalies and holoprosencephaly, and other diseases, including cancer. Signal transduction is initiated by HH ligand binding to the Patched 1 (PTCH1) receptor on primary cilia, thereby releasing inhibition of Smoothened (SMO), a HH pathway activator. Although cholesterol and several oxysterol lipids, which are enriched in the ciliary membrane, play a crucial role in HH activation, the molecular mechanisms governing the regulation of these lipid molecules remain unresolved. Here, we identify Canopy 4 (CNPY4), a Saposin-like protein, as a regulator of the HH pathway that controls membrane sterol lipid levels. Cnpy4—/— embryos exhibit multiple defects consistent with HH signaling perturbations, most notably changes in digit number. Knockdown of Cnpy4 hyperactivates the HH pathway at the level of SMO in vitro, and elevates membrane levels of accessible sterol lipids such as cholesterol, an endogenous ligand involved in SMO activation. Thus, our data demonstrate that CNPY4 is a negative regulator that fine-tunes the initial steps of HH signal transduction, revealing a previously undescribed facet of HH pathway regulation that operates through control of membrane composition.

scholarly journals Varicella-Zoster Virus Fc Receptor Component gI Is Phosphorylated on Its Endodomain by a Cyclin-Dependent Kinase

1999 ◽  
Vol 73 (2) ◽  
pp. 1320-1330 ◽  
Author(s):  
Ming Ye ◽  
Karen M. Duus ◽  
Junmin Peng ◽  
David H. Price ◽  
Charles Grose
Keyword(s):  
Fusion Protein ◽  
Varicella Zoster Virus ◽  
Phosphorylation Site ◽  
Cytoplasmic Tail ◽  
Casein Kinase Ii ◽  
Fc Receptor ◽  
Casein Kinase ◽  
Cyclin Dependent Kinase ◽  
Varicella Zoster

Varicella-zoster virus (VZV) glycoprotein gI is a type 1 transmembrane glycoprotein which is one component of the heterodimeric gE:gI Fc receptor complex. Like VZV gE, VZV gI was phosphorylated in both VZV-infected cells and gI-transfected cells. Preliminary studies demonstrated that a serine 343-proline 344 sequence located within the gI cytoplasmic tail was the most likely phosphorylation site. To determine which protein kinase catalyzed the gI phosphorylation event, we constructed a fusion protein, consisting of glutathione-S-transferase (GST) and the gI cytoplasmic tail, called GST-gI-wt. When this fusion protein was used as a substrate for gI phosphorylation in vitro, the results demonstrated that GST-gI-wt fusion protein was phosphorylated by a representative cyclin-dependent kinase (CDK) called P-TEFb, a homologue of CDK1 (cdc2). When serine 343 within the serine-proline phosphorylation site was replaced with an alanine residue, the level of phosphorylation of the gI fusion protein was greatly reduced. Subsequent experiments with individually immunoprecipitated mammalian CDKs revealed that the VZV gI fusion protein was phosphorylated best by CDK1, to a lesser degree by CDK2, and not at all by CDK6. Transient-transfection assays carried out in the presence of the specific CDK inhibitor roscovitine strongly supported the prior results by demonstrating a marked decrease in gI phosphorylation while gI protein expression was unaffected. Finally, the possibility that VZV gI contained a CDK phosphorylation site in its endodomain was of further interest because its partner, gE, contains a casein kinase II phosphorylation site in its endodomain; prior studies have established that CDK1 can phosphorylate casein kinase II.

scholarly journals Maturation of Embryonic Stem Cells Into Endothelial Cells in an In Vitro Model of Vasculogenesis

Blood ◽  
1999 ◽  
Vol 93 (4) ◽  
pp. 1253-1263 ◽  
Author(s):  
Masanori Hirashima ◽  
Hiroshi Kataoka ◽  
Satomi Nishikawa ◽  
Norihisa Matsuyoshi ◽  
Shin-Ichi Nishikawa
Keyword(s):  
Cell Adhesion ◽  
Endothelial Cell ◽  
Growth Factor ◽  
Culture System ◽  
Molecular Mechanisms ◽  
Es Cells ◽  
Embryonic Stem ◽  
Vascular Endothelial ◽  
Cell Cell

A primitive vascular plexus is formed through coordinated regulation of differentiation, proliferation, migration, and cell-cell adhesion of endothelial cell (EC) progenitors. In this study, a culture system was devised to investigate the behavior of purified EC progenitors in vitro. Because Flk-1+ cells derived from ES cells did not initially express other EC markers, they were sorted and used as EC progenitors. Their in vitro differentiation into ECs, via vascular endothelial-cadherin (VE-cadherin)+ platelet-endothelial cell adhesion molecule-1 (PECAM-1)+ CD34−to VE-cadherin+ PECAM-1+CD34+ stage, occurred without exogenous factors, whereas their proliferation, particularly at low cell density, required OP9 feeder cells. On OP9 feeder layer, EC progenitors gave rise to sheet-like clusters of Flk-1+ cells, with VE-cadherin concentrated at the cell-cell junction. The growth was suppressed by Flt-1-IgG1 chimeric protein and dependent on vascular endothelial growth factor (VEGF) but not placenta growth factor (PIGF). Further addition of VEGF resulted in cell dispersion, indicating the role of VEGF in the migration of ECs as well as their proliferation. Cell-cell adhesion of ECs in this culture system was mediated by VE-cadherin. Thus, the culture system described here is useful in dissecting the cellular events of EC progenitors that occur during vasculogenesis and in investigating the molecular mechanisms underlying these processes.

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