scholarly journals The Role of Glypican-1 in Regulating Multiple Cellular Signaling Pathways

2021 ◽  
Author(s):  
Jiajia Pan ◽  
Mitchell Ho
Keyword(s):  
Cell Membrane ◽  
Cell Surface ◽  
Signaling Pathways ◽  
Core Protein ◽  
Specific Interactions ◽  
Domain Interaction ◽  
Glycosyl Phosphatidylinositol ◽  
The Impact ◽  
Multiple Signaling

Glypican-1 (GPC1) is one of the six glypican family members in humans. It is composed of a core protein with three heparan sulfate chains, and attached to the cell membrane by a glycosyl-phosphatidylinositol anchor. GPC1 modulates various signaling pathways including FGF, VEGF-A, TGF-β, Wnt, Hh, and BMP through specific interactions with pathway ligands and receptors. The impact of these interactions on signaling pathways, activating or inhibitory, is dependent upon specific GPC1 domain interaction with pathway components as well as cell surface context. In this review, we summarize the current understanding of the structure of GPC1, as well as its role in regulating multiple signaling pathways. We focus on the functions of GPC1 in cancer cells and how new insights into these signaling processes can inform its translational potential as a therapeutic target in cancer.

Inhibitory role of oleanolic acid and esculetin in HeLa cells involve multiple signaling pathways

Gene ◽  
2021 ◽  
Vol 771 ◽  
pp. 145370
Author(s):  
Prajitha Mohandas Edathara ◽  
Shivakanth Chintalapally ◽  
Venkata Krishna Kanth Makani ◽  
Chitrakshi Pant ◽  
Suresh Yerramsetty ◽  
...  
Keyword(s):  
Signaling Pathways ◽  
Oleanolic Acid ◽  
Hela Cells ◽  
Inhibitory Role ◽  
Multiple Signaling

scholarly journals Cell Surface Expression of Endosomal Toll-Like Receptors—A Necessity or a Superfluous Duplication?

2021 ◽  
Vol 11 ◽  
Author(s):  
Matylda Barbara Mielcarska ◽  
Magdalena Bossowska-Nowicka ◽  
Felix Ngosa Toka
Keyword(s):  
Immune Response ◽  
Cell Membrane ◽  
Cell Surface ◽  
Signaling Pathways ◽  
Distinct Group ◽  
Cell Types ◽  
Cysteine Proteases ◽  
Cell Surface Expression ◽  
Critical Event ◽  
Toll Like Receptors

Timely and precise delivery of the endosomal Toll-like receptors (TLRs) to the ligand recognition site is a critical event in mounting an effective antimicrobial immune response, however, the same TLRs should maintain the delicate balance of avoiding recognition of self-nucleic acids. Such sensing is widely known to start from endosomal compartments, but recently enough evidence has accumulated supporting the idea that TLR-mediated signaling pathways originating in the cell membrane may be engaged in various cells due to differential expression and distribution of the endosomal TLRs. Therefore, the presence of endosomal TLRs on the cell surface could benefit the host responses in certain cell types and/or organs. Although not fully understood why, TLR3, TLR7, and TLR9 may occur both in the cell membrane and intracellularly, and it seems that activation of the immune response can be initiated concurrently from these two sites in the cell. Furthermore, various forms of endosomal TLRs may be transported to the cell membrane, indicating that this may be a normal process orchestrated by cysteine proteases—cathepsins. Among the endosomal TLRs, TLR3 belongs to the evolutionary distinct group and engages a different protein adapter in the signaling cascade. The differently glycosylated forms of TLR3 are transported by UNC93B1 to the cell membrane, unlike TLR7, TLR8, and TLR9. The aim of this review is to reconcile various views on the cell surface positioning of endosomal TLRs and add perspective to the implication of such receptor localization on their function, with special attention to TLR3. Cell membrane-localized TLR3, TLR7, and TLR9 may contribute to endosomal TLR-mediated inflammatory signaling pathways. Dissecting this signaling axis may serve to better understand mechanisms influencing endosomal TLR-mediated inflammation, thus determine whether it is a necessity for immune response or simply a circumstantial superfluous duplication, with other consequences on immune response.

A scale associated protein of Apedinella radians (Pedinellophyceae) and its possible role in the adhesion of surface components

1993 ◽  
Vol 104 (2) ◽  
pp. 391-398
Author(s):  
A. Koutoulis ◽  
M. Ludwig ◽  
R. Wetherbee
Keyword(s):  
Monoclonal Antibody ◽  
Monoclonal Antibodies ◽  
Cell Membrane ◽  
Cell Surface ◽  
Immunofluorescence Microscopy ◽  
Endomembrane System ◽  
Thin Sections ◽  
Specific Location ◽  
Whole Cells

Monoclonal antibodies have been generated against cell surface components of the unicellular phytoflagellate Apedinella radians (Pedinellophyceae). One monoclonal antibody, designated Arg 1E5/1B1, labels a scale associated protein (SAP) of 145 kDa. Immunofluorescence microscopy of whole cells as well as immunoelectron microscopy of whole cell mounts and thin sections using Arg 1E5/1B1 have shown that the SAP is located on the proximal surface of body scales and spine-scales. Its specific location suggests that the SAP may play a role in the adhesion of these surface components to the cell membrane and/or to one another. The potential of monoclonal antibody Arg 1E5/1B1 as a tool to study cell surface morphogenesis and the role of the endomembrane system in A. radians is discussed.

scholarly journals P110α and P110δ catalytic subunits of PI3 kinase regulate lysophosphatidylcholine-induced TRPC6 externalization

2021 ◽  
Author(s):  
Pinaki Chaudhuri ◽  
Andrew H. Smith ◽  
Priya Putta ◽  
Linda M. Graham ◽  
Michael A. Rosenbaum
Keyword(s):  
Signaling Pathways ◽  
Intracellular Signaling ◽  
Transient Receptor Potential ◽  
Oxidation Products ◽  
In Vivo Studies ◽  
Subsequent Increase ◽  
Lipid Oxidation Products ◽  
The Impact

Lipid oxidation products, including lysophosphatidylcholine (lysoPC) inhibit endothelial cell (EC) migration in vitro and impair EC healing of arterial injuries in vivo, in part by activating phosphatidylinositol 3-kinase (PI3K), which increases the externalization of canonical transient receptor potential 6 (TRPC6) channels and the subsequent increase in intracellular calcium. Inhibition of PI3K is a potential method to decrease TRPC6 activation and restore migration, but PI3K is involved in multiple intracellular signaling pathways and has multiple downstream effectors. The goal of this study is to identify the specific p110 catalytic subunit isoforms responsible for lysoPC-induced TRPC6 externalization to identify a target for intervention while minimizing impact on alternative signaling pathways. Down-regulation of the p110α and p110δ isoforms, but not the p110β or p110γ isoforms, with small interfering RNA significantly decreased phosphatidylinositol (3,4,5)-trisphosphate production and TRPC6 externalization, and significantly improved EC migration in the presence of lysoPC. These results identify an additional role of p110α in EC and reveal for the first time a specific role of p110δ in EC, providing a foundation for subsequent in vivo studies to investigate the impact of p110 isoform inhibition on arterial healing after injury.

scholarly journals Extracellular ATP plays an important role in systemic wound response activation

2022 ◽  
Author(s):  
Ronald Myers ◽  
Yosef Fichman ◽  
Gary Stacey ◽  
Ron Mittler
Keyword(s):  
Signaling Pathways ◽  
Extracellular Atp ◽  
Wound Response ◽  
Mechanical Wounding ◽  
Long Distance ◽  
Wound Responses ◽  
Systemic Signal ◽  
Electric Signals ◽  
Multiple Signaling

Mechanical wounding occurs in plants during biotic (e.g., herbivore or pathogen attack) or abiotic (e.g., wind damage or freezing) stresses and is associated with the activation of multiple signaling pathways. These initiate many wound responses at the wounded tissues, as well as trigger long-distance signaling pathways that activate wound responses in tissues that were not affected by the initial wounding event (termed systemic wound response). Among the different systemic signals activated by wounding are electric signals, calcium and reactive oxygen species (ROS) waves, and different plant hormones such as jasmonic acid. The release of glutamate from cells at the wounded tissues was recently proposed to trigger several different systemic signal transduction pathways via glutamate-like receptors (GLRs). However, the role of another important compound released from cells during wounding (i.e., extracellular ATP; eATP) in triggering systemic responses is not clear. Here we show that eATP that accumulates in wounded leaves and is sensed by the purinoreceptor kinase P2K is required for the activation of the ROS wave during wounding. Application of eATP to unwounded leaves triggered the ROS wave, and the activation of the ROS wave by wounding or eATP application was suppressed in mutants deficient in P2K (i.e., p2k1-3, p2k2, and p2k1-3p2k2). In addition, the expression of several systemic wound response transcripts was suppressed in mutants deficient in P2K during wounding. Our findings reveal that in addition to sensing glutamate via GLRs, eATP sensed by P2Ks is playing a key role in the triggering of systemic wound responses in plants.

scholarly journals Endothelial Cell Inflammation and Barriers Are Regulated by the Rab26-Mediated Balance between β2-AR and TLR4 in Pulmonary Microvessel Endothelial Cells

2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Huaping Chen ◽  
Ming Yuan ◽  
Chunji Huang ◽  
Zhi Xu ◽  
Mingchun Li ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Cell Membrane ◽  
Cell Surface ◽  
Cell Types ◽  
Tlr4 Expression ◽  
Barrier Dysfunction ◽  
Surface Receptors ◽  
G Protein Coupled

Rab26 GTPase modulates the trafficking of cell surface receptors, such as G protein-coupled receptors including α2-adrenergic receptors in some cell types. However, the effect of Rab26 on β2-adrenergic receptor (β2-AR) trafficking or/and Toll-like receptor 4 (TLR4) expression in human pulmonary microvascular endothelial cells (HPMECs) is still unclear. Here, we investigated the role of Rab26 in regulating the expression of β2-ARs and TLR4 in HPMECs and the effect of these receptors’ imbalance on endothelial cell barrier function. The results showed that there was unbalance expression in these receptors, where β2-AR expression was remarkably reduced, and TLR4 was increased on the cell membrane after lipopolysaccharide (LPS) treatment. Furthermore, we found that Rab26 overexpression not only upregulated β2-ARs but also downregulated TLR4 expression on the cell membrane. Subsequently, the TLR4-related inflammatory response was greatly attenuated, and the hyperpermeability of HPMECs also was partially relived. Taken together, these data suggest that basal Rab26 maintains the balance between β2-ARs and TLR4 on the cell surface, and it might be a potential therapeutic target for diseases involving endothelial barrier dysfunction.

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