scholarly journals Spatial-proteomics reveals phospho-signaling dynamics at subcellular resolution

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Ana Martinez-Val ◽  
Dorte B. Bekker-Jensen ◽  
Sophia Steigerwald ◽  
Claire Koenig ◽  
Ole Østergaard ◽  
...  

AbstractDynamic change in subcellular localization of signaling proteins is a general concept that eukaryotic cells evolved for eliciting a coordinated response to stimuli. Mass spectrometry-based proteomics in combination with subcellular fractionation can provide comprehensive maps of spatio-temporal regulation of protein networks in cells, but involves laborious workflows that does not cover the phospho-proteome level. Here we present a high-throughput workflow based on sequential cell fractionation to profile the global proteome and phospho-proteome dynamics across six distinct subcellular fractions. We benchmark the workflow by studying spatio-temporal EGFR phospho-signaling dynamics in vitro in HeLa cells and in vivo in mouse tissues. Finally, we investigate the spatio-temporal stress signaling, revealing cellular relocation of ribosomal proteins in response to hypertonicity and muscle contraction. Proteomics data generated in this study can be explored through https://SpatialProteoDynamics.github.io.

2021 ◽  
Author(s):  
Ana Martinez-Val ◽  
Dorte B. Bekker-Jensen ◽  
Sophia Steigerwald ◽  
Adi Mehta ◽  
Trung Tran ◽  
...  

AbstractDynamic change in subcellular localization of signaling proteins is a general concept that eukaryotic cells evolved for eliciting a coordinated response to stimuli. Mass spectrometry (MS)-based proteomics in combination with subcellular fractionation can provide comprehensive maps of spatio-temporal regulation of cells, but involves laborious workflows that does not cover the phospho-proteome level. Here we present a high-throughput workflow based on sequential cell fractionation to profile the global proteome and phospho-proteome dynamics across six distinct subcellular fractions. We benchmarked the workflow by studying spatio-temporal EGFR phospho-signaling dynamics in-vitro in HeLa cells and in-vivo in mouse tissues. Finally, we investigated the spatio-temporal stress signaling, revealing cellular relocation of ribosomal proteins in response to hypertonicity and muscle contraction. Proteomics data generated in this study can be explored through https://SpatialProteoDynamics.github.io.


1987 ◽  
Vol 104 (5) ◽  
pp. 1361-1374 ◽  
Author(s):  
J L Duband ◽  
S Dufour ◽  
K Hatta ◽  
M Takeichi ◽  
G M Edelman ◽  
...  

In avian embryos, somites constitute the morphological unit of the metameric pattern. Somites are epithelia formed from a mesenchyme, the segmental plate, and are subsequently reorganized into dermatome, myotome, and sclerotome. In this study, we used somitogenesis as a basis to examine tissue remodeling during early vertebrate morphogenesis. Particular emphasis was put on the distribution and possible complementary roles of adhesion-promoting molecules, neural cell adhesion molecule (N-CAM), N-cadherin, fibronectin, and laminin. Both segmental plate and somitic cells exhibited in vitro calcium-dependent and calcium-independent systems of cell aggregation that could be inhibited respectively by anti-N-cadherin and anti-N-CAM antibodies. In vivo, the spatio-temporal expression of N-cadherin was closely associated with both the formation and local disruption of the somites. In contrast, changes in the prevalence of N-CAM did not strictly accompany the remodeling of the somitic epithelium into dermamyotome and sclerotome. It was also observed that fibronectin and laminin were reorganized secondarily in the extracellular spaces after CAM-mediated contacts were modulated. In an in vitro culture system of somites, N-cadherin was lost on individual cells released from somite explants and was reexpressed when these cells reached confluence and established intercellular contacts. In an assay of tissue dissociation in vitro, antibodies to N-cadherin or medium devoid of calcium strongly and reversibly dissociated explants of segmental plates and somites. Antibodies to N-CAM exhibited a smaller disrupting effect only on segmental plate explants. In contrast, antibodies to fibronectin and laminin did not perturb the cohesion of cells within the explants. These results emphasize the possible role of cell surface modulation of CAMs during the formation and remodeling of some transient embryonic epithelia. It is suggested that N-cadherin plays a major role in the control of tissue remodeling, a process in which N-CAM is also involved but to a lesser extent. The substratum adhesion molecules, fibronectin and laminin, do not appear to play a primary role in the regulation of these processes but may participate in cell positioning and in the stabilization of the epithelial structures.


2003 ◽  
Vol 22 (10) ◽  
pp. 535-540 ◽  
Author(s):  
Berend T Leussink ◽  
Hans J Baelde ◽  
Thirza M Broekhuizen-van den Berg ◽  
Emile de Heer ◽  
Gijsbert B van der Voet ◽  
...  

Nephrotoxicity is the most important dose-limiting factor in cisplatin based anti-neoplastic treatment. Pretreatment with bismuth salts, used as pharmaceuticals to treat gastric disorders, has been demonstrated to reduce cisplatin-induced renal cell death in clinical settings and during in vivo and in vitro animal experiments. To investigate the genomic basis of this renoprotective effect, we exposed NRK-52E cells, a cell line of rat proximal tubular epithelial origin, to 33 mM Bi3 for 12 hours, which made them resistant to cisplatin-induced apoptosis. Differentially expressed genes in treated and untreated NRK-52E cells were detected by subtraction PCR and microarray techniques. Genes found to be down regulated (0.17 / 0.31-times) were cytochrome c oxidase subunit I, BAR (an apoptosis regulator), heat-shock protein 70-like protein, and three proteins belonging to the translation machinery (ribosomal proteins S7 and L17, and S1, a member of the elongation factor 1-alpha family). The only up-regulated gene was glutathione Stransferase subunit 3A (1.89-times). Guided by the expression levels of these genes, it may be possible to improve renoprotective treatments during anti-neoplastic therapies.


2021 ◽  
Author(s):  
Qianqian Sun ◽  
Kun Liu ◽  
Fangzhou Li ◽  
Bingquan Qiu ◽  
Zhisong Fu ◽  
...  

Abstract BackgroundThe disassembly of the replisome plays an essential role in maintaining genome stability at the termination of DNA replication. However, the mechanism of replisome disassembly remains unknown in human. In this study, we screened E3 ligases and deubiquitinases (DUBs) for the ubiquitination of minichromosome maintenance protein (MCM) 7 and provided evidence of this process driving CMG helicase disassembly in human tumor cells. MethodsSILAC-MS/MS was analyzed to identify ubiquitinated proteins in HeLa cells. The ubiquitination/deubiquitylation assay in vitro and in vivo were detected by Western blot. Thymidine and HU were implied to synchronized cell cycle,and detect the role of ubiquitinated MCM7 in cell cycle. Cell fractionation assay was used to detect the function of ubiquitination of MCM7 in chromatin and non-chromatin. Aphidicolin、Etoposide、ICRF-193 and IR were applied to cause replication fork stalling. MG-132 and NMS-873 were used to inhibit the proteasome degradation and p97 segregase. Flow cytometer and FlowJo flow cytometry software were used to cell cycle analysis.ResultsIn our study, we found that the ubiquitin ligase RNF8 catalyzes the k63-linked poly-ubiquitination of MCM7 both in vivo and in vitro, and lysine 145 of MCM7 is the primary ubiquitination site. Moreover, the poly-ubiquitination of MCM7 mainly exists in the chromatin, which is dynamically regulated by the cell cycle, mainly occurs in the late S phase. And DNA damage can significantly reduce the poly-ubiquitylation of MCM7 in the late S phage. Furthermore, the proteasome, p97 segregase, USP29 and ATXN3 are required for the removal of MCM7 ubiquitination to promote the disassembly of CMG on chromatin. ConclusionsIn the late S phage of cell cycle, RNF8 catalyzes the poly-ubiquitination of MCM7, and then initiates the disassembly of CMG helicase from chromatin, which is mediated by p97, proteasome, USP29 and ATXN3 in human. We reveal the novel function of the poly-ubiquitylation of MCM7, which is a regulatory signal to control CMG complex unloading at replication termination sites.


Development ◽  
1990 ◽  
Vol 109 (2) ◽  
pp. 395-409 ◽  
Author(s):  
B. Schlosshauer ◽  
D. Dutting ◽  
M. Wild

Using an immunosuppression technique, the monoclonal antibody 2A1 has been generated specific for a 140 × 10(3) Mr cytoplasmic-membrane-associated protein as shown by subcellular fractionation and Western blot analysis. The antigen is initially confined to perikarya of postmitotic migratory ganglion cells of the embryonic chick retina as revealed by bromodeoxyuridine labeling. During the subsequent period of axon outgrowth, the antigen becomes restricted to ganglion cell axons but disappears during the innervation of the tectum opticum, suggesting a tectal inhibition of antigen expression in retinal axons. To analyse whether the tectum suppresses 2A1-antigen expression, optic nerves of chick embryos were severed to prevent tectal innervation. 2A1-immunoreactivity was determined in deflected axons in comparison to control axons. In addition, retinal axons were grown in vitro on a substratum consisting of alternating stripes of laminin and tectal membranes, in order to investigate whether retinal axons become devoid of the 2A1-antigen once they cross from laminin to tectal membranes. However, neither prevention of target innervation by optic nerve transection in vivo nor exposure of retinal axons to soluble or particulate tectal components in vitro modify 2A1-antigen regulation in ganglion cell axons, suggesting a retina inherent-control of gene expression. Antigen expression is essentially restricted to the period of axonal outgrowth and therefore the 2A1-protein is likely to be involved in processes essential for neurite extension, independent of the synaptic target.


2012 ◽  
Vol 32 (suppl_1) ◽  
Author(s):  
Shin-Young Park ◽  
Chen Yan ◽  
Bradford C Berk

Introduction— Thioredoxin-interacting protein (TXNIP) is an arrestin-like scaffold protein. We have shown previously that it is necessary for the transactivation of the vascular endothelial growth factor (VEGF) receptor 2 (VEGFR2) as well as promoting the migration and survival of endothelial cells (ECs). However, its roles in VEGF-induced angiogenesis and in vivo studies of TXNIP function have not been elucidated. Hypothesis— TXNIP regulates VEGF-mediated angiogenesis through modulation of angiogenic signaling pathways in ECs. Methods and Results— To determine the functions of TXNIP in ECs, we generated endothelial-specific TXNIP knockout (EC-TXNIP KO) mice (TXNIPflox/flox: Tie2-Cre/+). These mice displayed impaired capillary growth of the retinal vasculature compared to control mice. Furthermore, aortic rings from EC-TXNIP KO mice exhibited fewer and shorter vascular sprouts than those in control mice. To investigate the role of TXNIP in the regulation of VEGF-induced angiogenesis, we determined the subcellular localization of TXNIP in human umbilical vein EC (HUVEC). Immunofluorescence and cell fractionation studies revealed that upon VEGF stimulation (10ng/ml). TXNIP translocated from cytoplasm to the plasma membrane. There was a 9 fold increase of membrane associated TXNIP with a peak at 15 minutes compared to non-VEGF treatment cells. We hypothesized that membrane associated TXNIP may modulate VEGFR2 internalization and thereby affect VEGF-induced signaling and angiogenesis. To investigate this, we performed in vitro cell surface biotinylation assays in HUVEC. VEGFR2 internalization was decreased by 65% in TXNIP siRNA knockdown cells compared to control siRNA treated cells following VEGF stimulation. Consistent with this result, VEGF-induced phosphorylation of VEGFR2, PLCγ and ERK1/2 was decreased by knockdown of TXNIP. Significantly, TXNIP knockdown inhibited VEGF-induced proliferation and tube formation in vitro. Conclusion— Our results suggest that TXNIP can modulate VEGF-induced angiogenesis and signaling by regulation of VEGFR2 internalization.


2020 ◽  
Vol 127 (Suppl_1) ◽  
Author(s):  
Zhongming Chen

Background: Cell migration is an important step involved in heart regeneration and many cardiovascular diseases. However, cell migration dynamics in vivo is poorly understood due to the challenges from mammal hearts, which are opaque and fast beating, and thus individual cardiac cells cannot be imaged or tracked. Aims: In this study, cell migration dynamics in the heart is recorded with a novel strategy, in which fluorescence protein-tagged collagen is secreted from cells and deposited into extracellular matrix, forming visible trails when cells are moving in tissues. As a proof-of-concept, transplanted migration dynamics of cardiac progenitor cells in mouse hearts were investaged. Methods: Stable cell lines expressing mCherry-tagged type I collagen were generated from isolated cardiac progenitor cells, ABCG2 + CD45 - CD31 - cells (side populations), or c-kit + CD45 - CD31 - cells (c-kit + CPCs). The cell migration dynamics were monitored and measured based on the cell trails after cell transplantation into mouse tissues. Results: The stable cell lines form red cell trails both in vitro and in vivo (Fig. 1A & 1B, Green: GFP; Red: mCherry-collagen I, Blue: DAPI, bar: 50 microns). In culture dishes, the cells form visible cell trails of fluorescence protein. The cell moving directions are random, with a speed of 288 +/- 79 microns/day (side populations, n=3) or 143 +/-37 microns/day (c-kit + CPCs, n=3). After transplantation into wild-type mouse hearts, the cells form highly tortuous trails along the gaps between the heart muscle fibers. Angle between a cell trail and a muscle fiber is 16+/-16 degree (n=3). Side populations migrate twice as fast as c-kit+ CPCs in the heart (16.0 +/-8.7 microns/day vs. 8.1+/-0.0 microns/day, n=3, respectively), 18 time slower than the respective speeds in vitro . Additionally, side populations migrate significantly faster in the heart than in the skeletal muscles (26.4+/-5.8 microns/day, n=3). The side populations move significantly faster in immunodeficient mouse hearts (36.7+/-13.3 microns/day, n=3, typically used for studying cell therapies) than in wild-type mouse hearts. Conclusion: For the first time, cell migration dynamics in living hearts is monitored and examined with genetically modified cell lines. This study may greatly advance the fields of cardiovascular biology.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
N. Träber ◽  
K. Uhlmann ◽  
S. Girardo ◽  
G. Kesavan ◽  
K. Wagner ◽  
...  

AbstractMechanical stress exerted and experienced by cells during tissue morphogenesis and organ formation plays an important role in embryonic development. While techniques to quantify mechanical stresses in vitro are available, few methods exist for studying stresses in living organisms. Here, we describe and characterize cell-like polyacrylamide (PAAm) bead sensors with well-defined elastic properties and size for in vivo quantification of cell-scale stresses. The beads were injected into developing zebrafish embryos and their deformations were computationally analyzed to delineate spatio-temporal local acting stresses. With this computational analysis-based cell-scale stress sensing (COMPAX) we are able to detect pulsatile pressure propagation in the developing neural rod potentially originating from polarized midline cell divisions and continuous tissue flow. COMPAX is expected to provide novel spatio-temporal insight into developmental processes at the local tissue level and to facilitate quantitative investigation and a better understanding of morphogenetic processes.


1998 ◽  
Vol 274 (6) ◽  
pp. F1054-F1061 ◽  
Author(s):  
Bento C. Santos ◽  
Alejandro Chevaile ◽  
Ryoji Kojima ◽  
Steven R. Gullans

Hsp110, Osp94, and Hsp70RY are members of the recently described Hsp110/SSE subfamily of (heat and osmotic) stress proteins whose members are structurally related to the Hsp70/BiP gene superfamily. To date, little is known about the response of this gene family to stresses in vitro or in vivo. In this study, an analysis of mRNA expression showed that Hsp110 and Osp94, like Hsp70, are induced in renal murine inner medullary collecting duct (mIMCD3) epithelial cells by heat shock, hyperosmotic NaCl, and cadmium, whereas low pH had a suppressive effect on Osp94. H2O2decreased expression of Osp94 while inducing levels of Hsp110 and Hsp70 message. Tunicamycin, hypertonic urea, and tumor necrosis factor-α had no effects. Hsp70RY was responsive exclusively to cadmium chloride. Moreover, enhanced expression of Hsp110 and Osp94 was subsequent to induction of Hsp70 and was suppressed by inhibition of protein synthesis by cycloheximide. RT-PCR analysis showed Hsp110, Osp94, and Hsp70RY are ubiquitously expressed in mouse tissues. In murine kidney, there was a corticomedullary gradient of expression of Hsp110, Osp94, Hsp70RY, and Hsp70 but not Hsc70 or BiP. Furthermore, dehydration increased inner medullary expression of Hsp110 and Osp94. An analysis of stress tolerance in mIMCD3 cells showed that heat shock and hyperosmotic NaCl stress are cross-tolerant stresses, suggesting hyperosmolality is a physiological correlate of heat shock in mammalian kidney. Thus Hsp110 and Osp94 behave as heat shock proteins, although they are regulated differently than Hsp70.


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