scholarly journals Golgi localization of the LIN-2/7/10 complex points to a role in basolateral secretion of LET-23 EGFR in the C. elegans vulval precursor cells

Development ◽  
2021 ◽  
pp. dev.194167
Author(s):  
Kimberley D. Gauthier ◽  
Christian E. Rocheleau
Keyword(s):  
Cell Fate ◽  
Spatial Organization ◽  
Basolateral Membrane ◽  
Growth Factor Receptor ◽  
Precursor Cells ◽  
C Elegans ◽  
Receptor Localization ◽  
Epidermal Growth ◽  
Complex Forms

The evolutionarily conserved LIN-2 (CASK)/LIN-7 (Lin7A-C)/LIN-10 (APBA1) complex plays an important role in regulating spatial organization of membrane proteins and signaling components. In C. elegans, the complex is essential for development of the vulva by promoting the localization of the sole Epidermal Growth Factor Receptor (EGFR) orthologue, LET-23, to the basolateral membrane of the vulva precursor cells (VPCs) where it can specify the vulval cell fate. To understand how the LIN-2/7/10 complex regulates receptor localization, we determined its expression and localization during vulva development. We found that LIN-7 colocalizes with LET-23 EGFR at the basolateral membrane, whereas the LIN-2/7/10 complex colocalizes with LET-23 EGFR at cytoplasmic punctae, that mostly overlap with the Golgi. Furthermore, LIN-10 recruits LIN-2, which in turn recruits LIN-7. We demonstrate that the complex forms in vivo with particularly strong interaction and colocalization between LIN-2 and LIN-7 consistent with their forming a subcomplex. Thus, the LIN-2/7/10 complex forms on the Golgi where it likely targets LET-23 EGFR trafficking to the basolateral membrane rather than functioning as a tether.

scholarly journals Dynamic expression and localization of the LIN-2/7/10 protein scaffolding complex during C. elegans vulval development

2020 ◽  
Author(s):  
Kimberley D. Gauthier ◽  
Christian E. Rocheleau
Keyword(s):  
Epidermal Growth Factor Receptor ◽  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Spatial Organization ◽  
Basolateral Membrane ◽  
Growth Factor Receptor ◽  
C Elegans ◽  
Epidermal Growth ◽  
Complex Forms

AbstractThe evolutionarily conserved LIN-2 (CASK)/LIN-7 (Lin7A-C)/LIN-10 (APBA1) complex plays an important role in regulating spatial organization of membrane proteins and signaling components. In C. elegans, the complex is essential for development of the vulva by promoting the localization of the sole Epidermal Growth Factor Receptor (EGFR) orthologue, LET-23, to the basolateral membrane of the vulva precursor cells (VPCs) where it can specify the vulval cell fate. However, the expression and localization of the LIN-2/7/10 complex, and how the complex regulates receptor localization, are not known. Here we describe an in vivo analysis of the complex in C. elegans VPCs. Only LIN-7 colocalizes with LET-23 EGFR at the basolateral membrane, while the LIN-2/7/10 complex components instead colocalize at cytoplasmic foci, consistent with Golgi or endosomes. LIN-10 recruits LIN-2, which in turn recruits LIN-7. We demonstrate that the complex forms in vivo with particularly strong interaction and colocalization between LIN-2 and LIN-7. Our data suggest that the LIN-2/7/10 complex forms on endomembrane compartments where it likely targets LET-23 EGFR to the basolateral membrane, and point to distinct regulation between LIN-2/7 and LIN-10.Summary StatementLIN-10 recruits LIN-2 and LIN-7 to Golgi or recycling endosomes, consistent with targeting rather than tethering the epidermal growth factor receptor to the basolateral membrane in C. elegans.

scholarly journals EGF signaling promotes the lineage conversion of astrocytes into oligodendroglias

2021 ◽  
Author(s):  
Xinyu Liu ◽  
Lesi Xie ◽  
Jiao Li ◽  
Conghui Li ◽  
Kang Zheng ◽  
...  
Keyword(s):  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Cell Fate ◽  
Growth Factor Receptor ◽  
Transition Process ◽  
Precursor Cells ◽  
Epidermal Growth ◽  
Egf Signaling

Abstract Background The conversion of astrocytes activated by nerve injuries to oligodendrocytes is not only beneficial to axonal remyelination, but also helpful for reversal of glial scar. Recent studies have shown that Sox10 transcription factor can achieve this transdifferentiation process in collaboration with some unknown factors in the pathological microenvironment. The extracellular factors underlying the cell fate switching are not known. Methods Astrocytes were obtained from mouse cortical dissociation culture and purified by differential adherent properties. The lineage conversion of astrocytes into oligodendrocyte lineage cells was carried out by Sox10-expressing virus infection both in vitro and in vivo, meanwhile, epidermal growth factor (EGF) and epidermal growth factor receptor (EGFR) inhibitor Gefitinib were adopted to investigate the function of EGF signaling in this fate transition process. Pharmacological inhibition analyses were performed to examine the pathway connecting the EGF with the expression of oligodendrogenic genes and cell fate transdifferentiation. Results EGF treatment facilitated the Sox10-induced transformation of astrocytes to O4+ induced oligodendrocyte precursor cells (iOPCs) in vitro. The transdifferentiation of astrocytes to iOPCs went through two distinct but interconnected processes: (1) dedifferentiation of astrocytes to astrocyte precursor cells (APCs); (2) transformation of APCs to iOPCs, EGF signaling was involved in both processes. And EGF triggered astrocytes to express oligodendrogenic genes Olig1 and Olig2 by activating extracellular signal-regulated kinase 1 and 2 (Erk1/2) pathway. In addition, we discovered that EGF can enhance astrocyte transdifferentiation in injured spinal cord tissues. Conclusions These findings provide strong evidence that EGF facilitates the transdifferentiation of astrocytes to oligodendroglias, and suggest that targeting the EGF-EGFR-Erk1/2 signaling axis may represent a novel therapeutic strategy for myelin repair in injured central nervous system (CNS) tissues.

scholarly journals Mouse embryo geometry drives formation of robust signaling gradients through receptor localization

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Zhechun Zhang ◽  
Steven Zwick ◽  
Ethan Loew ◽  
Joshua S. Grimley ◽  
Sharad Ramanathan
Keyword(s):  
Cell Fate ◽  
Mouse Embryo ◽  
Basolateral Membrane ◽  
Embryonic Stem ◽  
Bmp Signaling ◽  
Receptor Localization ◽  
Bmp Receptors ◽  
Early Mouse

Abstract Morphogen signals are essential for cell fate specification during embryogenesis. Some receptors that sense these morphogens are known to localize to only the apical or basolateral membrane of polarized cell lines in vitro. How such localization affects morphogen sensing and patterning in the developing embryo remains unknown. Here, we show that the formation of a robust BMP signaling gradient in the early mouse embryo depends on the restricted, basolateral localization of BMP receptors. The mis-localization of receptors to the apical membrane results in ectopic BMP signaling in the mouse epiblast in vivo. With evidence from mathematical modeling, human embryonic stem cells in vitro, and mouse embryos in vivo, we find that the geometric compartmentalization of BMP receptors and ligands creates a signaling gradient that is buffered against fluctuations. Our results demonstrate the importance of receptor localization and embryo geometry in shaping morphogen signaling during embryogenesis.

scholarly journals Signal co-operation between integrins and other receptor systems

2009 ◽  
Vol 418 (3) ◽  
pp. 491-506 ◽  
Author(s):  
Charles H. Streuli ◽  
Nasreen Akhtar
Keyword(s):  
Cell Fate ◽  
Tyrosine Kinases ◽  
Spatial Organization ◽  
Growth Factor Receptor ◽  
Cellular Processes ◽  
Extracellular Signals ◽  
Β1 Integrins ◽  
Α6β4 Integrin ◽  
Epidermal Growth ◽  
Adhesive Interactions

The multicellular nature of metazoans means that all cellular processes need to be tuned by adhesive interactions between cells and their local microenvironment. The spatial organization of cells within tissues requires sophisticated networks of extracellular signals to control their survival and proliferation, movements and positioning, and differentiated function. These cellular characteristics are mediated by multiple inputs from adhesion systems in combination with soluble and developmental signals. In the present review we explore how one class of adhesion receptor, the integrins, co-operate with other types of receptor to control diverse aspects of cell fate. In particular we discuss: (i) how β3 and β1 integrins work together with growth factors to control angiogenesis; (ii) how α6β4 integrin co-operates with receptor tyrosine kinases in normal epithelial function and cancer; (iii) the interplay between β1 integrins and EGF (epidermal growth factor) receptor; (iv) signal integration connecting integrins and cytokine receptors for interleukins, prolactin and interferons; and (v) how integrins and syndecans co-operate in cell migration.

scholarly journals LIN-10 can promote LET-23 EGFR signaling and trafficking independently of LIN-2 and LIN-7

2021 ◽  
pp. mbc.E20-07-0490
Author(s):  
Kimberley D. Gauthier ◽  
Christian E. Rocheleau
Keyword(s):  
Signal Transmission ◽  
Basolateral Membrane ◽  
Pdz Domain ◽  
Growth Factor Receptor ◽  
Pdz Domains ◽  
Egfr Signaling ◽  
Independent Function ◽  
Cell Fates ◽  
C Elegans ◽  
Epidermal Growth

During C. elegans larval development, an inductive signal mediated by LET-23 EGFR (Epidermal Growth Factor Receptor) specifies three of six vulva precursor cells (VPCs) to adopt vulval cell fates. An evolutionarily conserved complex consisting of PDZ domain-containing scaffold proteins LIN-2 (CASK), LIN-7 (Lin7 or Veli), and LIN-10 (APBA1 or Mint1) (LIN-2/7/10) mediates basolateral LET-23 EGFR localization in the VPCs to permit signal transmission and development of the vulva. We recently found that the LIN-2/7/10 complex likely forms at Golgi ministacks; however, the mechanism through which the complex targets the receptor to the basolateral membrane remains unknown. Here we found that overexpression of LIN-10 or LIN-7 can compensate for loss of their complex components by promoting LET-23 EGFR signaling through previously unknown complex-independent and receptor-dependent pathways. In particular, LIN-10 can independently promote basolateral LET-23 EGFR localization, and its complex-independent function uniquely requires its PDZ domains that also regulate its localization to Golgi. These studies point to a novel complex-independent function for LIN-7 and LIN-10 that broadens our understanding of how this complex regulates targeted sorting of membrane proteins.

scholarly journals LIN-10 can promote LET-23 EGFR signaling and trafficking independently of LIN-2 and LIN-7

2020 ◽  
Author(s):  
Kimberley D. Gauthier ◽  
Christian E. Rocheleau
Keyword(s):  
Signal Transmission ◽  
Basolateral Membrane ◽  
Pdz Domain ◽  
Growth Factor Receptor ◽  
Egfr Signaling ◽  
Independent Function ◽  
Cell Fates ◽  
Recycling Endosomes ◽  
C Elegans ◽  
Epidermal Growth

AbstractDuring C. elegans larval development, an inductive signal mediated by LET-23 EGFR (Epidermal Growth Factor Receptor) specifies three of six vulva precursor cells (VPCs) to adopt vulval cell fates. An evolutionarily conserved complex consisting of PDZ domain-containing scaffold proteins LIN-2 (CASK), LIN-7 (Lin7 or Veli), and LIN-10 (APBA1 or Mint1) (LIN-2/7/10) mediates basolateral LET-23 EGFR localization in the VPCs to permit signal transmission and development of the vulva. We recently found that the LIN-2/7/10 complex likely forms at Golgi ministacks or recycling endosomes; however, the mechanism through which the complex targets the receptor to the basolateral membrane remains unknown. Here we found that overexpression of LIN-10 or LIN-7 can compensate for loss of their complex components by promoting LET-23 EGFR signaling through previously unknown complex-independent and receptor-dependent pathways. In particular, LIN-10 can independently promote basolateral LET-23 EGFR localization, and its complex-independent function uniquely requires its PDZ domains that also regulate its localization to Golgi ministacks and recycling endosomes. These studies point to a novel complex-independent function for LIN-7 and LIN-10 that broadens our understanding of how this complex regulates targeted sorting of membrane proteins.

Toxicity and efficacy evaluation of multiple targeted polymalic acid conjugates for triple-negative breast cancer treatment

2020 ◽  
Author(s):  
Lungwani Muungo
Keyword(s):  
Triple Negative ◽  
Growth Factor Receptor ◽  
Engineered Nanoparticles ◽  
Efficacy Evaluation ◽  
Dual Action ◽  
Epidermal Growth ◽  
Laminin 411 ◽  
Immunologic Analysis

Engineered nanoparticles are widely used for delivery of drugs but frequently lack proof of safetyfor cancer patient's treatment. All-in-one covalent nanodrugs of the third generation have beensynthesized based on a poly(β-L-malic acid) (PMLA) platform, targeting human triple-negativebreast cancer (TNBC). They significantly inhibited tumor growth in nude mice by blockingsynthesis of epidermal growth factor receptor, and α4 and β1 chains of laminin-411, the tumorvascular wall protein and angiogenesis marker. PMLA and nanodrug biocompatibility and toxicityat low and high dosages were evaluated in vitro and in vivo. The dual-action nanodrug and singleactionprecursor nanoconjugates were assessed under in vitro conditions and in vivo with multipletreatment regimens (6 and 12 treatments). The monitoring of TNBC treatment in vivo withdifferent drugs included blood hematologic and immunologic analysis after multiple intravenousadministrations. The present study demonstrates that the dual-action nanoconju-gate is highlyeffective in preclinical TNBC treatment without side effects, supported by hematologic andimmunologic assays data. PMLA-based nanodrugs of the Polycefin™ family passed multipletoxicity and efficacy tests in vitro and in vivo on preclinical level and may prove to be optimizedand efficacious for the treatment of cancer patients in the future.

scholarly journals Syndecan Transmembrane Domain Specifically Regulates Downstream Signaling Events of the Transmembrane Receptor Cytoplasmic Domain

2021 ◽  
Vol 22 (15) ◽  
pp. 7918
Author(s):  
Jisun Hwang ◽  
Bohee Jang ◽  
Ayoung Kim ◽  
Yejin Lee ◽  
Joonha Lee ◽  
...  
Keyword(s):  
Transmembrane Domain ◽  
Growth Factor Receptor ◽  
Cytoplasmic Domain ◽  
Nih3t3 Cells ◽  
C Elegans ◽  
Downstream Signaling ◽  
Downstream Effectors ◽  
Signaling Events

Despite the known importance of the transmembrane domain (TMD) of syndecan receptors in cell adhesion and signaling, the molecular basis for syndecan TMD function remains unknown. Using in vivo invertebrate models, we found that mammalian syndecan-2 rescued both the guidance defects in C. elegans hermaphrodite-specific neurons and the impaired development of the midline axons of Drosophila caused by the loss of endogenous syndecan. These compensatory effects, however, were reduced significantly when syndecan-2 dimerization-defective TMD mutants were introduced. To further investigate the role of the TMD, we generated a chimera, 2eTPC, comprising the TMD of syndecan-2 linked to the cytoplasmic domain of platelet-derived growth factor receptor (PDGFR). This chimera exhibited SDS-resistant dimer formation that was lost in the corresponding dimerization-defective syndecan-2 TMD mutant, 2eT(GL)PC. Moreover, 2eTPC specifically enhanced Tyr 579 and Tyr 857 phosphorylation in the PDGFR cytoplasmic domain, while the TMD mutant failed to support such phosphorylation. Finally, 2eTPC, but not 2eT(GL)PC, induced phosphorylation of Src and PI3 kinase (known downstream effectors of Tyr 579 phosphorylation) and promoted Src-mediated migration of NIH3T3 cells. Taken together, these data suggest that the TMD of a syndecan-2 specifically regulates receptor cytoplasmic domain function and subsequent downstream signaling events controlling cell behavior.

scholarly journals Imaging-Guided Therapy Simultaneously Targeting HER2 and EpCAM with Trastuzumab and EpCAM-Directed Toxin Provides Additive Effect in Ovarian Cancer Model

Cancers ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 3939
Author(s):  
Tianqi Xu ◽  
Anzhelika Vorobyeva ◽  
Alexey Schulga ◽  
Elena Konovalova ◽  
Olga Vorontsova ◽  
...  
Keyword(s):  
Ovarian Cancer ◽  
Growth Factor Receptor ◽  
Repeated Administration ◽  
Ovarian Cancer Cells ◽  
Her2 Positive ◽  
Efficient Treatment ◽  
Pseudomonas Exotoxin A ◽  
Epidermal Growth

Efficient treatment of disseminated ovarian cancer (OC) is challenging due to its heterogeneity and chemoresistance. Overexpression of human epidermal growth factor receptor 2 (HER2) and epithelial cell adhesion molecule (EpCAM) in approx. 30% and 70% of ovarian cancers, respectively, allows for co-targeted treatment. The clinical efficacy of the monoclonal antibody trastuzumab in patients with HER2-positive breast, gastric and gastroesophageal cancers makes it readily available as the HER2-targeting component. As the EpCAM-targeting component, we investigated the designed ankyrin repeat protein (DARPin) Ec1 fused to a truncated variant of Pseudomonas exotoxin A with reduced immunogenicity and low general toxicity (LoPE). Ec1-LoPE was radiolabeled, evaluated in ovarian cancer cells in vitro and its biodistribution and tumor-targeting properties were studied in vivo. The therapeutic efficacy of Ec1-LoPE alone and in combination with trastuzumab was studied in mice bearing EpCAM- and HER2-expressing SKOV3 xenografts. SPECT/CT imaging enabled visualization of EpCAM and HER2 expression in the tumors. Co-treatment using Ec1-LoPE and trastuzumab was more effective at reducing tumor growth and prolonged the median survival of mice compared with mice in the control and monotherapy groups. Repeated administration of Ec1-LoPE was well tolerated without signs of hepatic or kidney toxicity. Co-treatment with trastuzumab and Ec1-LoPE might be a potential therapeutic strategy for HER2- and EpCAM-positive OC.

Sign in / Sign up

Export Citation Format

Share Document