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.

Cellular Samurai: katanin and the severing of microtubules

2000 ◽  
Vol 113 (16) ◽  
pp. 2821-2827 ◽  
Author(s):  
L. Quarmby
Keyword(s):  
Epithelial Cells ◽  
Essential Role ◽  
Aaa Atpase ◽  
C Elegans ◽  
Microtubule Severing ◽  
Biochemical Studies ◽  
New Evidence

Recent biochemical studies of the AAA ATPase, katanin, provide a foundation for understanding how microtubules might be severed along their length. These in vitro studies are complemented by a series of recent reports of direct in vivo observation of microtubule breakage, which indicate that the in vitro phenomenon of catalysed microtubule severing is likely to be physiological. There is also new evidence that microtubule severing by katanin is important for the production of non-centrosomal microtubules in cells such as neurons and epithelial cells. Although it has been difficult to establish the role of katanin in mitosis, new genetic evidence indicates that a katanin-like protein, MEI-1, plays an essential role in meiosis in C. elegans. Finally, new proteins involved in the severing of axonemal microtubules have been discovered in the deflagellation system of Chlamydomonas.

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.

scholarly journals picd-1, a gene that encodes CABIN1 domain-containing protein, interacts with pry-1/Axin to regulate multiple processes in Caenorhabditis elegans

2021 ◽  
Author(s):  
Avijit Mallick ◽  
Shane K. B. Taylor ◽  
Sakshi Mehta ◽  
Bhagwati P. Gupta
Keyword(s):  
Stress Response ◽  
Essential Role ◽  
Family Members ◽  
Transcriptome Profiling ◽  
Scaffolding Protein ◽  
Dependent Manner ◽  
C Elegans ◽  
Downstream Effectors ◽  
Cellular Components

ABSTRACTAXIN family members control diverse biological processes in eukaryotes. As a scaffolding protein, AXIN facilitates interactions between cellular components and provides specificity to signaling pathways. Despite its crucial roles in metazoans and discovery of a large number of family members, the mechanism of AXIN function is not very well understood. The C. elegans AXIN homolog PRY-1 provides a powerful tool to identify interacting genes and downstream effectors that function in a conserved manner to regulate AXIN-mediated signaling. Previous work demonstrated pry-1’s essential role in developmental processes such as reproductive system, seam cells, and a P lineage cell P11.p. More recently, our lab carried out a transcriptome profiling of pry-1 mutant and uncovered the essential role of the gene in lipid metabolism, stress response, and aging. In this study, we have extended the work on pry-1 by reporting a novel interacting gene picd-1 (pry-1-interacting CABIN1 domain containing). Our findings have revealed that picd-1 plays an essential role in C. elegans and is involved in several pry-1-mediated processes including regulation of stress response and lifespan maintenance. In support of this, picd-1 expression overlaps with pry-1 in multiple tissues throughout the lifespan of animals. Further experiments showed that picd-1 inhibits CREB-regulated transcriptional coactivator homolog CRTC-1 function, which promotes longevity in a calcineurin-dependent manner. These data provide evidence for an essential role of the CABIN1 domain protein PICD-1 in mediating PRY-1 signaling in C. elegans.

scholarly journals Lineage-specific requirements of β-catenin in neural crest development

2002 ◽  
Vol 159 (5) ◽  
pp. 867-880 ◽  
Author(s):  
Lisette Hari ◽  
Véronique Brault ◽  
Maurice Kléber ◽  
Hye-Youn Lee ◽  
Fabian Ille ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Neural Crest ◽  
Neural Crest Cells ◽  
Neural Crest Stem Cells ◽  
Downstream Signaling ◽  
Neural Crest Development ◽  
Sensory Neurogenesis

β-Catenin plays a pivotal role in cadherin-mediated cell adhesion. Moreover, it is a downstream signaling component of Wnt that controls multiple developmental processes such as cell proliferation, apoptosis, and fate decisions. To study the role of β-catenin in neural crest development, we used the Cre/loxP system to ablate β-catenin specifically in neural crest stem cells. Although several neural crest–derived structures develop normally, mutant animals lack melanocytes and dorsal root ganglia (DRG). In vivo and in vitro analyses revealed that mutant neural crest cells emigrate but fail to generate an early wave of sensory neurogenesis that is normally marked by the transcription factor neurogenin (ngn) 2. This indicates a role of β-catenin in premigratory or early migratory neural crest and points to heterogeneity of neural crest cells at the earliest stages of crest development. In addition, migratory neural crest cells lateral to the neural tube do not aggregate to form DRG and are unable to produce a later wave of sensory neurogenesis usually marked by the transcription factor ngn1. We propose that the requirement of β-catenin for the specification of melanocytes and sensory neuronal lineages reflects roles of β-catenin both in Wnt signaling and in mediating cell–cell interactions.

scholarly journals LINC00037 Inhibits Proliferation of Renal Cell Carcinoma Cells in an Epidermal Growth Factor Receptor-Dependent Way

2018 ◽  
Vol 45 (2) ◽  
pp. 523-536 ◽  
Author(s):  
Xiaohui Gong ◽  
Xianjin Du ◽  
Yong Xu ◽  
Wenze Zheng
Keyword(s):  
Cell Cycle ◽  
Renal Cell Carcinoma ◽  
Cell Proliferation ◽  
Epidermal Growth Factor Receptor ◽  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Growth Factor Receptor ◽  
Epidermal Growth

Background/Aims: LINC00037 has previously been reported to be up-regulated in clear cell renal cell carcinoma (ccRCC), however, the underlying mechanism remained unknown. In this study, we designed to investigate the functional role of LINC00037 in ccRCC Methods: LINC00037 knockdown and re-expressing 786-O and A498 cells were established. CCK8 assay and EdU assay were performed to evaluate the proliferation rates of ccRCC cells. Flow cytometry assay was performed to detect the cell apoptosis and cell cycle. Subcutaneous injection xenotransplantation mouse model was used to observe the role of LINC00037 in tumor growth in vivo. Mass spectrometry (MS) was performed to find the interacting partner of LINC00037 and RNA immunoprecipitation (RIP) was carried out to validate their interaction. Results: We found that knockdown of LINC00037 resulted in inhibited cell proliferation with activated apoptosis and cell cycle arrest in vitro. Over-expression of LINC00037 in LINC00037 knockdown cells restored and enhanced cell proliferation. In vivo mouse model indicated reduced tumor progression by LINC00037 depletion and promoted tumor progression by LINC00037 overexpression. LINC00037 could bind to epidermal growth factor receptor (EGFR) and increase the protein level of EGFR. Conclusion: LINC00037 could inhibit proliferation of ccRCC in an epidermal growth factor receptor-dependent way.

scholarly journals Role of PARP1-mediated autophagy in EGFR-TKI resistance in non-small cell lung cancer

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Zhimin Zhang ◽  
Xiaojuan Lian ◽  
Wei Xie ◽  
Jin Quan ◽  
Maojun Liao ◽  
...  
Keyword(s):  
Lung Cancer ◽  
Kinase Inhibitors ◽  
Growth Factor Receptor ◽  
Advanced Lung Cancer ◽  
Tki Resistance ◽  
Geo Dataset ◽  
Epidermal Growth

AbstractResistance to epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) has become the main clinical challenge of advanced lung cancer. This research aimed to explore the role of PARP1-mediated autophagy in the progression of TKI therapy. PARP1-mediated autophagy was evaluated in vitro by CCK-8 assay, clonogenic assay, immunofluorescence, and western blot in the HCC-827, H1975, and H1299 cells treated with icotinib (Ico), rapamycin, and AZD2281 (olaparib) alone or in combination. Our results and GEO dataset analysis confirmed that PARP1 is expressed at lower levels in TKI-sensitive cells than in TKI-resistant cells. Low PARP1 expression and high p62 expression were associated with good outcomes among patients with NSCLC after TKI therapy. AZD2281 and a lysosomal inhibitor reversed resistance to Ico by decreasing PARP1 and LC3 in cells, but an mTOR inhibitor did not decrease Ico resistance. The combination of AZD2281 and Ico exerted a markedly enhanced antitumor effect by reducing PARP1 expression and autophagy in vivo. Knockdown of PARP1 expression reversed the resistance to TKI by the mTOR/Akt/autophagy pathway in HCC-827IR, H1975, and H1299 cells. PARP1-mediated autophagy is a key pathway for TKI resistance in NSCLC cells that participates in the resistance to TKIs. Olaparib may serve as a novel method to overcome the resistance to TKIs.

scholarly journals MiR199a is implicated in embryo implantation by regulating Grb10 in rat

Reproduction ◽  
2014 ◽  
Vol 147 (1) ◽  
pp. 91-99 ◽  
Author(s):  
Hong-Fei Xia ◽  
Jing-Li Cao ◽  
Xiao-Hua Jin ◽  
Xu Ma
Keyword(s):  
Cell Proliferation ◽  
Embryo Implantation ◽  
Growth Factor Receptor ◽  
Inverse Association ◽  
Loss Of Function ◽  
Endometrial Stromal Cells ◽  
Proliferation And Apoptosis ◽  
17Β Estradiol

MiR199a was found to be differentially expressed in rat uteri between the prereceptive and receptive phase via microRNA (miRNA) microarray analysis in our previous study. However, the role of miR199a in rat embryo implantation remained unknown. In the study, northern blot results showed that the expression levels of miR199a were higher on gestation days 5 and 6 (g.d.5–6) in rat uteri than on g.d.3–4 and g.d.7–8. In situ localization of miR199a in rat uteri showed that miR199a was mainly localized in the stroma or decidua. The expression of miR199a was not significantly different in the uteri of pseudopregnant rats and evidently increased in the uteri of rats subjected to activation of delayed implantation and experimentally induced decidualization. Treatment with 17β-estradiol or both 17β-estradiol and progesterone significantly diminished miR199a levels. Gain of function of miR199a in endometrial stromal cells isolated from rat uteri inhibited cell proliferation and promoted cell apoptosis. Loss of function of miR199a displayed opposite roles on cell proliferation and apoptosis. Further investigation uncovered a significant inverse association between the expression of miR199a and growth factor receptor-bound protein 10 (Grb10), an imprinted gene, and miR199a could bind to the 3′UTR of Grb10 to inhibit Grb10 translation. In addition, in vivo analysis found that the immunostaining of GRB10 was attenuated in the stroma or decidua from g.d.4 to 6, contrary to the enhancement of miR199a. Collectively, upregulation of miR199a in rat uterus during the receptive phase is regulated by blastocyst activation and uterine decidualization. Enforced miR199a expression suppresses cell proliferation partially through targeting Grb10.

scholarly journals mTORC1/rpS6 regulates blood-testis barrier dynamics and spermatogenetic function in the testis in vivo

2018 ◽  
Vol 314 (2) ◽  
pp. E174-E190 ◽  
Author(s):  
Stephen Y. T. Li ◽  
Ming Yan ◽  
Haiqi Chen ◽  
Tito Jesus ◽  
Will M. Lee ◽  
...  
Keyword(s):  
Mammalian Target Of Rapamycin ◽  
Downstream Signaling ◽  
Signaling Complex ◽  
Adult Rat ◽  
Mammalian Expression ◽  
Ribosomal Protein S6 ◽  
Spatiotemporal Expression ◽  
Blood Testis Barrier

The blood-testis barrier (BTB), conferred by Sertoli cells in the mammalian testis, is an important ultrastructure that supports spermatogenesis. Studies using animal models have shown that a disruption of the BTB leads to meiotic arrest, causing defects in spermatogenesis and male infertility. To better understand the regulation of BTB dynamics, we report findings herein to understand the role of ribosomal protein S6 (rpS6), a downstream signaling protein of mammalian target of rapamycin complex 1 (mTORC1), in promoting BTB disruption in the testis in vivo, making the barrier “leaky.” Overexpression of wild-type rpS6 (rpS6-WT, the full-length cDNA cloned into the mammalian expression vector pCI-neo) and a constitutively active quadruple phosphomimetic mutant cloned into pCI-neo (p-rpS6-MT) vs. control (empty pCI-neo vector) was achieved by transfecting adult rat testes with the corresponding plasmid DNA using a Polyplus in vivo-jetPEI transfection reagent. On the basis of an in vivo functional BTB integrity assay, p-rpS6-MT was found to induce BTB disruption better than rpS6-WT did (and no effects in empty vector control), leading to defects in spermatogenesis, including loss of spermatid polarity and failure in the transport of cells (e.g., spermatids) and organelles (e.g., phagosomes), to be followed by germ exfoliation. More important, rpS6-WT and p-rpS6-MT exert their disruptive effects through changes in the organization of actin- and microtubule (MT)-based cytoskeletons, which are mediated by changes in the spatiotemporal expression of actin- and MT-based binding and regulatory proteins. In short, mTORC1/rpS6 signaling complex is a regulator of spermatogenesis and BTB by modulating the organization of the actin- and MT-based cytoskeletons.

scholarly journals Spongiform Neurodegeneration-associated E3 Ligase Mahogunin Ubiquitylates TSG101 and Regulates Endosomal Trafficking

2007 ◽  
Vol 18 (4) ◽  
pp. 1129-1142 ◽  
Author(s):  
Bong Yoon Kim ◽  
James A. Olzmann ◽  
Gregory S. Barsh ◽  
Lih-Shen Chin ◽  
Lian Li
Keyword(s):  
Mammalian Cells ◽  
Growth Factor Receptor ◽  
Endosomal Trafficking ◽  
Small Interfering Rnas ◽  
Gene Encoding ◽  
Endosomal Sorting ◽  
Ubiquitin Protein Ligase ◽  
Downstream Signaling

A null mutation in the gene encoding the putative E3 ubiquitin–protein ligase Mahogunin causes spongiform neurodegeneration, a recessively transmitted prion-like disease in mice. However, no substrates of Mahogunin have been identified, and the cellular role of Mahogunin is unknown. Here, we report the identification of TSG101, a key component of the endosomal sorting complex required for transport (ESCRT)-I, as a specific Mahogunin substrate. We find that Mahogunin interacts with the ubiquitin E2 variant (UEV) domain of TSG101 via its PSAP motif and that it catalyzes monoubiquitylation of TSG101 both in vivo and in vitro. Depletion of Mahogunin by small interfering RNAs in mammalian cells disrupts endosome-to-lysosome trafficking of epidermal growth factor receptor, resulting in prolonged activation of a downstream signaling cascade. Our findings support a role for Mahogunin in a proteasome-independent ubiquitylation pathway and suggest a link between dysregulation of endosomal trafficking and spongiform neurodegeneration.

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