Live-Cell FRET Imaging of Phosphorylation-Dependent Caveolin-1 Switch

2020 ◽  
pp. 71-80
Author(s):  
Adriana M. Zimnicka ◽  
Zhenlong Chen ◽  
Peter T. Toth ◽  
Richard D. Minshall
Keyword(s):  
Live Cell ◽  
Caveolin 1

scholarly journals Live-cell single-molecule imaging reveals clathrin and caveolin-1 dependent docking of SMAD4 at the cell membrane

FEBS Letters ◽  
2013 ◽  
Vol 587 (24) ◽  
pp. 3912-3920 ◽  
Author(s):  
Yong Yang ◽  
Joy Wolfram ◽  
Jianliang Shen ◽  
Yuliang Zhao ◽  
Xiaohong Fang ◽  
...  
Keyword(s):  
Cell Membrane ◽  
Single Molecule ◽  
Live Cell ◽  
Single Molecule Imaging ◽  
Caveolin 1

Aberrant cytoplasmic sequestration of eNOS in endothelial cells after monocrotaline, hypoxia, and senescence: live-cell caveolar and cytoplasmic NO imaging

2007 ◽  
Vol 292 (3) ◽  
pp. H1373-H1389 ◽  
Author(s):  
Somshuvra Mukhopadhyay ◽  
Fang Xu ◽  
Pravin B. Sehgal
Keyword(s):  
Endothelial Cells ◽  
Pulmonary Hypertension ◽  
Plasma Membrane ◽  
Live Cell ◽  
Caveolin 1 ◽  
Protein Levels ◽  
Pulmonary Arterial ◽  
And Function ◽  
Endothelial Nitric Oxide ◽  
Arterial Endothelial Cells

We previously reported the disruption of caveolae/rafts, dysfunction of Golgi tethers, N-ethylmaleimide-sensitive factor-attachment protein (SNAP) receptor proteins (SNAREs), and SNAPs, and inhibition of anterograde trafficking in endothelial cells in culture and rat lung exposed to monocrotaline pyrrole (MCTP) as a prelude to the development of pulmonary hypertension. We have now investigated 1) whether this trafficking block affects subcellular localization and function of endothelial nitric oxide (NO) synthase (eNOS) and 2) whether Golgi blockade and eNOS sequestration are observed after hypoxia and senescence. Immunofluorescence data revealed that MCTP-induced “megalocytosis” of pulmonary arterial endothelial cells (PAEC) was accompanied by a loss of eNOS from the plasma membrane, with increased accumulation in the cytoplasm. This cytoplasmic eNOS was sequestered in heterogeneous compartments and partially colocalized with Golgi and endoplasmic reticulum (ER) markers, caveolin-1, NOSTRIN, and ER Tracker, but not Lyso Tracker. Hypoxia and senescence also produced enlarged PAEC, with dysfunctional Golgi and loss of eNOS from the plasma membrane, with sequestration in the cytoplasm. Live-cell imaging of caveolar and cytoplasmic NO with 4,5-diaminofluorescein diacetate (DAF-2DA) as probe showed a marked loss of caveolar NO after MCTP, hypoxia, and senescence. Although ionomycin stimulated DAF-2DA fluorescence in control PAEC, this ionophore decreased DAF-2DA fluorescence in MCTP-treated and senescent PAEC, suggesting localization of eNOS in an aberrant cytoplasmic compartment that was readily discharged by Ca2+-induced exocytosis. Thus monocrotaline, hypoxia, and senescence produce a Golgi blockade in PAEC, leading to sequestration of eNOS away from its functional caveolar location and providing a mechanism for the often-reported reduction in pulmonary arterial NO levels in experimental pulmonary hypertension, despite sustained eNOS protein levels.

Live cell imaging of interleukin-6-induced targeting of “transcription factor” STAT3 to sequestering endosomes in the cytoplasm

2007 ◽  
Vol 293 (4) ◽  
pp. C1374-C1382 ◽  
Author(s):  
Fang Xu ◽  
Somshuvra Mukhopadhyay ◽  
Pravin B. Sehgal
Keyword(s):  
Plasma Membrane ◽  
Live Cell Imaging ◽  
Cell Imaging ◽  
Direct Evidence ◽  
Live Cell ◽  
Dominant Negative ◽  
Adapter Protein ◽  
Toll Like Receptor ◽  
Caveolin 1 ◽  
Induced Signal

Signal transducer and activator of transcription (STAT) family transcription factors are classically viewed as transducing cytokine- and growth factor-activated signals from the plasma membrane to the cell nucleus for the purpose of activating transcription. We report live cell imaging studies of fluorescently labeled STAT3 expressed in Hep3B hepatocytes that reveal interleukin (IL)-6-activated targeting of STAT3 and PY-STAT3 to relatively long-lived sequestering endosomes in the cytoplasm. This targeting was rapid but transient, required phosphorylation and integrity of Tyr 705 in STAT3, and was blocked by nocodazole, geldanamycin, and indirubin E804 and by overexpression of wild-type caveolin-1. Strikingly, overexpression of the dominant-negative (DN) mutant K44A of the GTPase dynamin II led to marked constitutive accumulation of STAT3 in the endocytic compartment with depletion of the STAT3 nuclear pool. Subsets of the native and K44A-generated STAT3- and PY-STAT3-sequestering endosomes colocalized with MyD88, an adapter protein that integrates pathways of Toll-like receptor and IL-1 transcriptional signaling and stabilization of mRNAs. These data provide direct evidence for the cytokine-induced “signal transduction” by STAT3 from the plasma membrane to a cytoplasmic membrane destination for yet to be elucidated function(s) in the cytoplasm including prolongation of signaling and/or cross talk.

1422: Oxytocin Receptor and Caveolin-1 Expression in the Prostate of Young and Aging Male

2005 ◽  
Vol 173 (4S) ◽  
pp. 385-386
Author(s):  
Gregor Bötticher ◽  
Zsófia Herbert ◽  
Erdogan Sendemir ◽  
Andreas Aschoff ◽  
Gustav Friedrich Jirikowski ◽  
...  
Keyword(s):  
Oxytocin Receptor ◽  
Aging Male ◽  
Caveolin 1

Modulation der TGF-β abhängigen CTGF Induktion durch Caveolin-1 in Hepatozyten

2009 ◽  
Vol 47 (09) ◽  
Author(s):  
C Meyer ◽  
C Stump ◽  
A Müller ◽  
S Dooley
Keyword(s):  
Caveolin 1

Caveolin-1 Deficiency Protects Pancreatic ß Cells against Palmitate-Induced Dysfunction and Apoptosis

Diabetes ◽  
2018 ◽  
Vol 67 (Supplement 1) ◽  
pp. 84-OR
Author(s):  
WEN ZENG ◽  
KUNYING LIU ◽  
JIANSONG TANG ◽  
HAICHENG LI ◽  
HAIXIA XU ◽  
...  
Keyword(s):  
Caveolin 1

α-Methylene-β-Lactone Probe for Measuring Live-Cell Reactions of Small Molecules

2020 ◽  
Author(s):  
Lei Wang ◽  
Louis Riel ◽  
Bekim Bajrami ◽  
Bin Deng ◽  
Amy Howell ◽  
...  
Keyword(s):  
Mass Spectra ◽  
Live Cell ◽  
Live Cells ◽  
The Novel ◽  
Proteomics Analysis ◽  
Chemical Proteomics ◽  
Tandem Mass Spectra ◽  
Modified Peptides ◽  
Covalent Probes ◽  
Ht 29

The novel use of the α-methylene-β-lactone (MeLac) moiety as a warhead of multiple electrophilic sites is reported. In this study, we demonstrate that a MeLac-alkyne is a competent covalent probe and reacts with diverse proteins in live cells. Proteomics analysis of affinity-enriched samples identifies probe-reacted proteins, resolves their modified peptides/residues, and thus characterizes probe-protein reactions. Unique methods are developed to evaluate confidence in the identification of the reacted proteins and modified peptides. Tandem mass spectra of the peptides reveal that MeLac reacts with nucleophilic cysteine, serine, lysine, threonine, and tyrosine residues, through either Michael addition or acyl addition. A peptide-centric proteomics platform, using MeLac-alkyne as the measurement probe, successfully analyzes the Orlistat selectivity in live HT-29 cells. MeLac is a versatile warhead demonstrating enormous potential to expedite the development of covalent probes and inhibitors in interrogating protein (re)activity. MeLac-empowered platforms in chemical proteomics are widely adaptable for measuring the live-cell action of reactive molecules.

CLINICAL SIGNIFICANCE OF SERUM CAVEOLIN-1 LEVELS IN GASTRIC CANCER PATIENTS

2018 ◽  
Vol 40 (4) ◽  
pp. 323-327 ◽  
Author(s):  
F Tas ◽  
S Karabulut ◽  
K Erturk ◽  
D Duranyildiz
Keyword(s):  
Gastric Cancer ◽  
Cancer Patients ◽  
Histological Grade ◽  
Clinical Importance ◽  
Disease Stage ◽  
Control Group ◽  
Tissue Samples ◽  
Caveolin 1 ◽  
Study Results ◽  
Gastric Cancer Patients

Aim: Caveolin-1 plays a significant role in the pathogenesis of various carcinomas and its expression affects the survival of cancer patients. However, the molecular function of caveolin-1 and its possible clinical importance has remained uncertain in gastric cancer. No clinical trial has examined serum caveolin-1 levels in gastric cancer patients so far, instead all available results were provided from studies conducted on tissue samples. In the current study, we analyzed the soluble serum caveolin-1 levels in gastric cancer patients, and specified its associations with the clinical factors and prognosis. Material and Methods: Sixty-three patients with pathologically confirmed gastric cancer were enrolled into the trial. Serum caveolin-1 concentrations were detected by ELISA method. Thirty healthy subjects were also included in the study. Results: The median age of patients was 62 years, ranging from 28 to 82 years. The serum caveolin-1 levels in gastric cancer patients were significantly higher than those in control group (p < 0.001). The common clinical parameters including patient age, sex, lesion localization, histopathology, histological grade, disease stage, and various serum tumor markers (e.g. LDH, CEA, and CA 19.9) were not found to be associated with serum caveolin-1 levels (p > 0.05). Similarly, no correlation existed between serum caveolin-1 concentration and chemotherapy responsiveness (p = 0.93). Furthermore, serum caveolin-1 level was not found to have a prognostic role (p = 0.16). Conclusion: Even though it is neither predictive nor prognostic, serum caveolin-1 level may be a valuable diagnostic indicator in patients with gastric cancer. Key

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