scholarly journals The Multifaceted Roles of the Tumor Susceptibility Gene 101 (TSG101) in Normal Development and Disease

Cancers ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 450 ◽  
Author(s):  
Rosa-Maria Ferraiuolo ◽  
Karoline C. Manthey ◽  
Marissa J. Stanton ◽  
Aleata A. Triplett ◽  
Kay-Uwe Wagner
Keyword(s):  
Susceptibility Gene ◽  
Structural Features ◽  
Genetically Engineered ◽  
Cellular Functions ◽  
Tumor Susceptibility ◽  
Cancer Models ◽  
Critical Issues ◽  
Tumor Susceptibility Gene

The multidomain protein encoded by the Tumor Susceptibility Gene 101 (TSG101) is ubiquitously expressed and is suggested to function in diverse intracellular processes. In this review, we provide a succinct overview of the main structural features of the protein and their suggested roles in molecular and cellular functions. We then summarize, in more detail, key findings from studies using genetically engineered animal models that demonstrate essential functions of TSG101 in cell proliferation and survival, normal tissue homeostasis, and tumorigenesis. Despite studies on cell lines that provide insight into the molecular underpinnings by which TSG101 might function as a negative growth regulator, a biologically significant role of TSG101 as a tumor suppressor has yet to be confirmed using genuine in vivo cancer models. More recent observations from several cancer research teams suggest that TSG101 might function as an oncoprotein. A potential role of post-translational mechanisms that control the expression of the TSG101 protein in cancer is being discussed. In the final section of the review, we summarize critical issues that need to be addressed to gain a better understanding of biologically significant roles of TSG101 in cancer.

scholarly journals Isolation and Characterization of Human Adipocyte-derived Extracellular Vesicles Using Filtration and Ultracentrifugation

2020 ◽  
Author(s):  
Naveed Akbar ◽  
Katherine E. Pinnick ◽  
Daan Paget ◽  
Robin P. Choudhury
Keyword(s):  
Endothelial Cells ◽  
Adipose Tissue ◽  
Extracellular Vesicles ◽  
Peripheral Blood ◽  
Susceptibility Gene ◽  
Nanoparticle Tracking Analysis ◽  
Human Adipocyte ◽  
Tumor Susceptibility ◽  
Tumor Susceptibility Gene

ABSTRACTExtracellular vesicles (EVs) are lipid enclosed envelopes that carry biologically active material such as proteins, RNA, metabolites and lipids. EVs can modulate the cellular status of other cells locally in tissue microenvironments or through liberation into peripheral blood. Adipocyte- derived EVs are elevated in the peripheral blood and show alterations in their cargo (RNA and protein) during metabolic disturbances including, obesity and diabetes. Adipocyte-derived EVs can regulate the cellular status of neighboring vascular cells, such as endothelial cells and adipose tissue resident macrophages to promote adipose tissue inflammation. Investigating alterations in adipocyte-derived EVs in vivo is complex because EVs derived from peripheral blood are highly heterogenous and contain EVs from other sources, namely platelets, endothelial cells, erythrocytes and muscle. Therefore, the culture of human adipocytes provides a model system for the study of adipocyte derived EVs. Here, we provide a detailed protocol for the extraction of total small EVs from cell culture media of human gluteal and abdominal adipocytes using filtration and ultracentrifugation. We further demonstrate the use of Nanoparticle Tracking Analysis (NTA) for quantification of EV size and concentration and show the presence of EV-protein tumor susceptibility gene 101 (TSG101) in the gluteal and abdominal adipocyte derived-EVs. Isolated EVs from this protocol can be used for downstream analysis including, transmission electron microscopy, proteomics, metabolomics, small RNA-sequencing, microarray and utilized in functional in vitro/in vivo studies.SUMMARYWe describe the isolation of human adipocyte-derived extracellular vesicles (EVs) from gluteal and abdominal adipose tissue using filtration and ultracentrifugation. We characterize the isolated adipocyte-derived EVs by determining their size and concentration by Nanoparticle Tracking Analysis and by western blotting for the presence of EV-protein tumor susceptibility gene 101 (TSG101).

Tumor susceptibility gene-101 regulates glucocorticoid receptor through disorder-mediated allostery

2020 ◽  
Author(s):  
Jordan T. White ◽  
James Rives ◽  
Marla E. Tharp ◽  
James O. Wrabl ◽  
E. Brad Thompson ◽  
...  
Keyword(s):  
Glucocorticoid Receptor ◽  
Hormone Receptors ◽  
Susceptibility Gene ◽  
Coiled Coil ◽  
Steroid Hormone Receptors ◽  
Tumor Susceptibility ◽  
Cellular Assays ◽  
Tumor Susceptibility Gene

AbstractTumor Susceptibility Gene-101 (TSG101) is involved in endosomal maturation and has been implicated in the transcriptional regulation of several steroid hormone receptors (SHRs), although a detailed characterization of such regulation has yet to be conducted. Here we directly measure binding of TSG101 to one SHR, glucocorticoid receptor (GR). Using biophysical and cellular assays, we show that the coiled-coil domain of TSG101; 1) binds and folds the disordered N-terminal domain (NTD) of GR, 2) upon binding, improves DNA-binding of GR in vitro, and 3) enhances the transcriptional activity of GR in vivo. Our findings suggest that TSG101 is a bona fide transcriptional co-regulator of GR.

scholarly journals Active role of free RNA during the early phase of proteostasis stress

2019 ◽  
Author(s):  
Marion Alriquet ◽  
Adrían Martínez-Limón ◽  
Gerd Hanspach ◽  
Martin Hengesbach ◽  
Gian G. Tartaglia ◽  
...  
Keyword(s):  
Rna Binding ◽  
Rna Binding Proteins ◽  
Active Form ◽  
Active Role ◽  
Structural Features ◽  
Cellular Functions ◽  
Granule Formation

ABSTRACTTransient sequestration of proteins and RNA is an essential principle of cellular reaction to stress. Compared to polypeptides, less is known about the role of RNA released from polysomes during acute proteostasis stress. Using quantitative mass spectrometry, we identified a set of proteins assembled by free RNA in the heat-shocked mammalian cytosol. RNA-associated proteins displayed higher disorder and larger size, which supports the role of multivalent interactions during the initial phase of the RNA granule formation. Structural features of the free RNA interactors defined them as a subset of RNA-binding proteins. The interactome contained preferentially the active form of eIF2α. The interaction between assembled proteins in vivo required RNA. The reconstitution of the association process in vitro indicated to the multimolecular basis for the increased binding to RNA upon heat shock in the cytosol. Our results reveal how free RNA can participate in reorganization of cellular functions during proteostasis stress.

scholarly journals Lysosomal Localization of Ubiquitinated Jun Requires Multiple Determinants in a Lysine-27–Linked Polyubiquitin Conjugate

2008 ◽  
Vol 19 (11) ◽  
pp. 4588-4601 ◽  
Author(s):  
Hiromi Ikeda ◽  
Tom K. Kerppola
Keyword(s):  
Protein Localization ◽  
Susceptibility Gene ◽  
Wild Type ◽  
Cellular Functions ◽  
E3 Ligases ◽  
Kinase Substrate ◽  
Tumor Susceptibility ◽  
The Mean ◽  
Tumor Susceptibility Gene ◽  
Hepatocyte Growth

Ubiquitination regulates many cellular functions, including protein localization and degradation. Each function is specified by unique determinants in the conjugate. Ubiquitinated Jun is localized to lysosomes for degradation. Here, we characterized determinants of Jun ubiquitination and lysosomal localization by using ubiquitin-mediated fluorescence complementation (UbFC) in living cells and analysis of the stoichiometry of ubiquitin linked to Jun extracted from cells. The δ region of Jun and isoleucine-44 in ubiquitin were required for lysosomal localization of the conjugate. Ubiquitin containing only lysine-27, but no other single-lysine ubiquitin, mediated Jun ubiquitination, albeit at lower stoichiometry than wild-type ubiquitin. These conjugates were predominantly nuclear, but coexpression of lysine-27 and lysine-less ubiquitins enhanced the mean stoichiometry of Jun ubiquitination and lysosomal localization of the conjugate. Hepatocyte growth factor-regulated tyrosine kinase substrate (HRS) and tumor susceptibility gene 101 (TSG101) colocalized with ubiquitinated Jun. Knockdown of HRS or TSG101 inhibited lysosomal localization of ubiquitinated Jun and reduced Jun turnover. Ubiquitination of other Fos and Jun family proteins had distinct effects on their localization. Our results indicate that Jun is polyubiquitinated by E3 ligases that produce lysine-27–linked chains. Lysosomal localization of the conjugate requires determinants in Jun and in ubiquitin that are recognized in part by TSG101 and HRS, facilitating selective translocation and degradation of ubiquitinated Jun.

scholarly journals The value of Wilms tumor susceptibility gene 1 in cytologic preparations as a marker for malignant mesothelioma

Cancer ◽  
2002 ◽  
Vol 96 (2) ◽  
pp. 105-109 ◽  
Author(s):  
Jonathan L. Hecht ◽  
Benjamin H. Lee ◽  
Jack L. Pinkus ◽  
Geraldine S. Pinkus
Keyword(s):  
Malignant Mesothelioma ◽  
Wilms Tumor ◽  
Susceptibility Gene ◽  
Tumor Susceptibility ◽  
Tumor Susceptibility Gene

scholarly journals Molecular Basis for CCRL2 Regulation of Leukocyte Migration

2020 ◽  
Vol 8 ◽  
Author(s):  
Tiziana Schioppa ◽  
Francesca Sozio ◽  
Ilaria Barbazza ◽  
Sara Scutera ◽  
Daniela Bosisio ◽  
...  
Keyword(s):  
Cancer Progression ◽  
Chemokine Receptors ◽  
Transmembrane Domain ◽  
Nk Cell ◽  
Structural Features ◽  
Negative Regulator ◽  
Leukocyte Migration ◽  
Genetic Ablation

CCRL2 is a seven-transmembrane domain receptor that belongs to the chemokine receptor family. At difference from other members of this family, CCRL2 does not promote chemotaxis and shares structural features with atypical chemokine receptors (ACKRs). However, CCRL2 also differs from ACKRs since it does not bind chemokines and is devoid of scavenging functions. The only commonly recognized CCRL2 ligand is chemerin, a non-chemokine chemotactic protein. CCRL2 is expressed both by leukocytes and non-hematopoietic cells. The genetic ablation of CCRL2 has been instrumental to elucidate the role of this receptor as positive or negative regulator of inflammation. CCRL2 modulates leukocyte migration by two main mechanisms. First, when CCRL2 is expressed by barrier cells, such endothelial, and epithelial cells, it acts as a presenting molecule, contributing to the formation of a non-soluble chemotactic gradient for leukocytes expressing CMKLR1, the functional chemerin receptor. This mechanism was shown to be crucial in the induction of NK cell-dependent immune surveillance in lung cancer progression and metastasis. Second, by forming heterocomplexes with other chemokine receptors. For instance, CCRL2/CXCR2 heterodimers were shown to regulate the activation of β2-integrins in mouse neutrophils. This mini-review summarizes the current understanding of CCRL2 biology, based on experimental evidence obtained by the genetic deletion of this receptor in in vivo experimental models. Further studies are required to highlight the complex functional role of CCRL2 in different organs and pathological conditions.

Processing of eukaryotic pre-rRNA: the role of the transcribed spacers

1995 ◽  
Vol 73 (11-12) ◽  
pp. 789-801 ◽  
Author(s):  
Rob W. van Nues ◽  
Jaap Venema ◽  
Jeanette M. J. Rientjes ◽  
Anita Dirks-Mulder ◽  
Hendrik A. Raué
Keyword(s):  
Mutational Analysis ◽  
Structural Features ◽  
28S Rrna ◽  
Cis Acting ◽  
Processing Elements ◽  
Rrna Species ◽  
Polymerase I ◽  
Precursor Transcript

The 17–18S, 5.8S, and 25–28S rRNA species of eukaryotic cells are produced by a series of nucleolytic reactions that liberate the mature rRNAs from the large primary precursor transcript synthesized by RNA polymerase I. Whereas the order of the cleavage reactions has long been established, until recently little information was available on their molecular details, such as the nature of the proteins, including the nucleolytic enzymes, involved and the signals directing the processing machinery to the correct sites. This situation is now rapidly changing, in particular where yeast is concerned. The use of recently developed systems for in vivo mutational analysis of yeast rDNA has considerably enhanced our knowledge of cis-acting structural features within the pre-rRNA, in particular the transcribed spacer sequences, that are critical for correct and efficient removal of these spacers. The same systems also allow a link to be forged between trans-acting processing factors and these cis-acting elements. In this paper, we will focus predominantly on the nature and role of the cis-acting processing elements as identified in the transcribed spacer regions of Saccharomyces cerevisiae pre-rRNA.Key words: ribosome, processing, precursor rRNA, eukaryote, transcribed spacer.

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