scholarly journals Reciprocal EGFR signaling in the anchor cell ensures precise inter-organ connection during Caenorhabditis elegans vulval morphogenesis

Development ◽  
2022 ◽  
Vol 149 (1) ◽  
Author(s):  
Silvan Spiri ◽  
Simon Berger ◽  
Louisa Mereu ◽  
Andrew DeMello ◽  
Alex Hajnal
Keyword(s):  
Caenorhabditis Elegans ◽  
Egf Receptor ◽  
Adherens Junctions ◽  
Egfr Signaling ◽  
Cell Fates ◽  
Vulval Development ◽  
Sequence Of Events ◽  
Epidermal Growth ◽  
Short And Long Term ◽  
Anchor Cell

ABSTRACT During Caenorhabditis elegans vulval development, the uterine anchor cell (AC) first secretes an epidermal growth factor (EGF) to specify the vulval cell fates and then invades the underlying vulval epithelium. By doing so, the AC establishes direct contact with the invaginating primary vulF cells and attaches the developing uterus to the vulva. The signals involved and the exact sequence of events joining these two organs are not fully understood. Using a conditional let-23 EGF receptor (EGFR) allele along with novel microfluidic short- and long-term imaging methods, we discovered a specific function of the EGFR in the AC during vulval lumen morphogenesis. Tissue-specific inactivation of let-23 in the AC resulted in imprecise alignment of the AC with the primary vulval cells, delayed AC invasion and disorganized adherens junctions at the contact site forming between the AC and the dorsal vulF toroid. We propose that EGFR signaling, activated by a reciprocal EGF cue from the primary vulval cells, positions the AC at the vulval midline, guides it during invasion and assembles a cytoskeletal scaffold organizing the adherens junctions that connect the developing uterus to the dorsal vulF toroid. Thus, EGFR signaling in the AC ensures the precise alignment of the two developing organs.

scholarly journals Reciprocal EGFR signaling in the Anchor Cell ensures precise inter-organ connection during C. elegans vulval morphogenesis

2021 ◽  
Author(s):  
Silvan Spiri ◽  
Simon Berger ◽  
Louisa Mereu ◽  
Andrew DeMello ◽  
Alex Hajnal
Keyword(s):  
Egf Receptor ◽  
Adherens Junctions ◽  
Egfr Signaling ◽  
Cell Fates ◽  
Vulval Development ◽  
C Elegans ◽  
Sequence Of Events ◽  
Epidermal Growth ◽  
Short And Long Term ◽  
Anchor Cell

During C. elegans vulval development, the uterine anchor cell (AC) first secretes an epidermal growth factor (EGF) to specify the vulval cell fates and then invades into the underlying vulval epithelium. Thereby, the AC establishes direct contact with the invaginating primary vulF cells and attaches the developing uterus to the vulva. The signals involved and the exact sequence of events joining these two organs are not fully understood. Using a conditional let-23 egf receptor (EGFR) allele along with novel microfluidic short- and long-term imaging methods, we discovered a specific function of the EGFR in the AC during vulval lumen morphogenesis. Tissue-specific inactivation of let-23 in the AC resulted in imprecise alignment of the AC with the primary vulval cells, delayed AC invasion and disorganized adherens junctions at the newly forming contact site between the AC and the dorsal vulF toroid. We propose that EGFR signaling, activated by a reciprocal EGF cue from the primary vulval cells, positions the AC at the vulval midline, guides it during invasion and assembles a cytoskeletal scaffold organizing the adherens junctions that connect the developing uterus to the dorsal vulF toroid. EGFR signaling in the AC thus ensures the precise alignment of the two developing organs.

scholarly journals Multiple functions of let-23, a Caenorhabditis elegans receptor tyrosine kinase gene required for vulval induction.

Genetics ◽  
1991 ◽  
Vol 128 (2) ◽  
pp. 251-267 ◽  
Author(s):  
R V Aroian ◽  
P W Sternberg
Keyword(s):  
Caenorhabditis Elegans ◽  
Tyrosine Kinase ◽  
Receptor Tyrosine Kinase ◽  
Egf Receptor ◽  
Kinase Gene ◽  
Multiple Functions ◽  
Tyrosine Kinase Gene ◽  
Receptor Tyrosine Kinase Gene ◽  
Epidermal Growth ◽  
Mutant Phenotypes

Abstract The let-23 gene, which encodes a putative tyrosine kinase of the epidermal growth factor (EGF) receptor subfamily, has multiple functions during Caenorhabditis elegans development. We show that let-23 function is required for vulval precursor cells (VPCs) to respond to the signal that induces vulval differentiation: a complete loss of let-23 function results in no induction. However, some let-23 mutations that genetically reduce but do not eliminate let-23 function result in VPCs apparently hypersensitive to inductive signal: as many as five of six VPCs can adopt vulval fates, in contrast to the three that normally do. These results suggest that the let-23 receptor tyrosine kinase controls two opposing pathways, one that stimulates vulval differentiation and another that negatively regulates vulval differentiation. Furthermore, analysis of 16 new let-23 mutations indicates that the let-23 kinase functions in at least five tissues. Since various let-23 mutant phenotypes can be obtained independently, the let-23 gene is likely to have tissue-specific functions.

scholarly journals Rab8 and Rabin8-Mediated Tumor Formation by Hyperactivated EGFR Signaling via FGFR Signaling

2020 ◽  
Vol 21 (20) ◽  
pp. 7770
Author(s):  
Junghwa Choi ◽  
Jee Young Sung ◽  
Saerom Lee ◽  
Jungyoen Yoo ◽  
Christopher Rongo ◽  
...  
Keyword(s):  
Growth Factor Receptor ◽  
Tumor Model ◽  
Tumor Formation ◽  
Rab Proteins ◽  
Egfr Signaling ◽  
Vulval Development ◽  
C Elegans ◽  
Exon 19 Deletion ◽  
Epidermal Growth ◽  
Egfr Tki

The epidermal growth factor receptor (EGFR) signaling is important for normal development, such as vulval development in Caenorhabditis elegans, and hyperactivation of the EGFR is often associated with cancer development. Our previous report demonstrated the multivulva (Muv) phenotype, a tumor model in C. elegans (jgIs25 strain) by engineering LET-23/EGFR with a TKI-resistant human EGFR T790-L858 mutant. Because Rab proteins regulate vesicle transport, which is important for receptor signaling, we screened the RNAi in the jgIs25 strain to find the Rabs critical for Muv formation. Herein, we show that rab-8 RNAi and the rab-8 (-/-) mutation effectively reduce Muv formation. We demonstrate that RABN-8, an ortholog of Rabin8, known as a GEF for Rab8, is also required for Muv formation by promoting the secretion of EGL-17/FGF from vulval precursor cells. In addition, FGFR inhibitors decreased Muv formation mediated by mutant EGFR. Our data suggest that Rab8 and Rabin8 mediate Muv formation through FGF secretion in the EGFR-TKI-resistant nematode model. Furthermore, FGFR-TKIs more effectively inhibit the growth of lung cancer cell lines in H1975 (EGFR T790M-L858R; EGFR-TKI-resistant) than H522 (wild-type EGFR) and H1650 (EGFR exon 19 deletion; EGFR-TKI-sensitive) cells, suggesting that FGFR-TKIs could be used to control cancers with EGFR-TKI-resistant mutations.

scholarly journals Cell fate-specific regulation of EGF receptor trafficking during Caenorhabditis elegans vulval development

2006 ◽  
Vol 25 (11) ◽  
pp. 2347-2357 ◽  
Author(s):  
Attila Stetak ◽  
Erika Fröhli Hoier ◽  
Assunta Croce ◽  
Giuseppe Cassata ◽  
Pier Paolo Di Fiore ◽  
...  
Keyword(s):  
Caenorhabditis Elegans ◽  
Cell Fate ◽  
Egf Receptor ◽  
Receptor Trafficking ◽  
Vulval Development ◽  
Specific Regulation

scholarly journals Genetic Analysis of the Caenorhabditis elegans MAP Kinase Gene mpk-1

Genetics ◽  
1998 ◽  
Vol 150 (1) ◽  
pp. 103-117 ◽  
Author(s):  
Mark R Lackner ◽  
Stuart K Kim
Keyword(s):  
Transcription Factor ◽  
Caenorhabditis Elegans ◽  
Map Kinase ◽  
Double Mutant ◽  
Cell Fates ◽  
Gain Of Function ◽  
Kinase Gene ◽  
Epistasis Analysis ◽  
Anchor Cell ◽  
Ets Transcription Factor

Abstract The Caenorhabditis elegans mpk-1 gene encodes a MAP kinase protein that plays an important role in Ras-mediated induction of vulval cell fates. We show that mutations that eliminate mpk-1 activity result in a highly penetrant, vulvaless phenotype. A double mutant containing a gain-of-function mpk-1 mutation and a gain-of-function mek mutation (MEK phosphorylates and activates MPK-1) exhibits a multivulva phenotype. These results suggest that mpk-1 may transduce most or all of the anchor cell signal. Epistasis analysis suggests that mpk-1 acts downstream of mek-2 (encodes a MEK homolog) and upstream of lin-1 (encodes an Ets transcription factor) in the anchor cell signaling pathway. Finally, mpk-1 may act together with let-60 ras in multiple developmental processes, as mpk-1 mutants exhibit nearly the same range of developmental phenotypes as let-60 ras mutants.

Alternative Pathways of Epidermal Growth Factor Receptor Mediated Contractile Force in NR6 Fibroblasts

1999 ◽  
Author(s):  
Fred D. Allen ◽  
Clara F. Asnes ◽  
Alan Wells ◽  
Elliot L. Elson ◽  
Douglas A. Lauffenburger
Keyword(s):  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Egf Receptor ◽  
Mapk Pathway ◽  
Contractile Force ◽  
Mitogen Activated Protein Kinase ◽  
Egfr Signaling ◽  
Signaling Mechanism ◽  
Force Increase ◽  
Epidermal Growth

Abstract We investigated the contractile force response to epidermal growth factor (EGF) stimulation in 3T3-derived NR6 fibroblast cells in order to determine significant pathways of biochemical signaling that mediate the response. We examined the force generating specificity of the EGF receptor (EGFR) signaling mechanism by using mutant NR6 fibroblasts expressing variations of the EGFR construct. The wild-type (WT) cell presented the complete internalizing EGFR signaling construct while the c’973 cell presented an internalization-defective EGFR construct, and the M721 cell presented a kinase-defective EGFR construct making it signaling inert. Additionally we examined the roles of the phospholipasc C-γ (PLCγ) pathway by using the PLC inhibitor U73122 (1 μM) and the mitogen activated protein kinase (MAPK) pathway using the inhibitor PD98059 (10 μM) in the observed contractile force responses. We found that the WT cells showed a rapid but transient force increase within the first hour post-stimulation and the c’973 showed a more gradual increase in force which it sustained for several hours post-stimulation. Blocking the PLCγ activation in the WT cells reduced the peak force increase by 50% while blocking MAPK did not affect the force development in either WT or c’973 cells.

scholarly journals The lin-15 locus encodes two negative regulators of Caenorhabditis elegans vulval development.

1994 ◽  
Vol 5 (4) ◽  
pp. 395-411 ◽  
Author(s):  
L S Huang ◽  
P Tzou ◽  
P W Sternberg
Keyword(s):  
Caenorhabditis Elegans ◽  
Null Allele ◽  
Negative Regulator ◽  
Vulval Development ◽  
Genetic Studies ◽  
Vulval Precursor Cells ◽  
Complex Locus ◽  
Anchor Cell ◽  
Inductive Signal

During Caenorhabditis elegans vulval development, an inductive signal from the anchor cell stimulates three of the six vulval precursor cells (VPCs) to adopt vulval rather than nonvulval epidermal fates. Genes necessary for this induction include the lin-3 growth factor, the let-23 receptor tyrosine kinase, and let-60 ras. lin-15 is a negative regulator of this inductive pathway. In lin-15 mutant animals, all six VPCs adopt vulval fates, even in the absence of inductive signal. Previous genetic studies suggested that lin-15 is a complex locus with two independently mutable activities, A and B. We have cloned the lin-15 locus by germline transformation and find that it encodes two nonoverlapping transcripts that are transcribed in the same direction. The downstream transcript encodes the lin-15A function; the upstream transcript encodes the lin-15B function. The predicted lin-15A and lin-15B proteins are novel and hydrophilic. We have identified a molecular null allele of lin-15 and have used it to analyze the role of lin-15 in the signaling pathway. We find that lin-15 acts upstream of let-23 and in parallel to the inductive signal.

scholarly journals Functional domains of LAG-2, a putative signaling ligand for LIN-12 and GLP-1 receptors in Caenorhabditis elegans.

1997 ◽  
Vol 8 (9) ◽  
pp. 1751-1762 ◽  
Author(s):  
S T Henderson ◽  
D Gao ◽  
S Christensen ◽  
J Kimble
Keyword(s):  
Caenorhabditis Elegans ◽  
Signal Transduction Pathway ◽  
Transgenic Animals ◽  
Functional Domains ◽  
Membrane Association ◽  
Cell Fates ◽  
Apparent Reduction ◽  
Epidermal Growth ◽  
Mutant Rescue

The LAG-2 membrane protein is a putative signaling ligand for the LIN-12 and GLP-1 receptors of Caenorhabditis elegans. LAG-2, like its Drosophila homologues Delta and Serrate, acts in a conserved signal transduction pathway to regulate cell fates during development. In this article, we investigate the functional domains of LAG-2. For the most part, mutants were constructed in vitro and assayed for activity in transgenic animals. We find a functional role for all major regions except one. Within the extracellular domain, the N-terminal region, which bears no known motif, and the DSL domain are both required. By contrast, the region bearing epidermal growth factor-like repeats can be deleted with no apparent reduction in rescuing activity. The intracellular region is not required for activity but instead plays a role in down-regulating LAG-2 function. Finally, membrane association is critical for mutant rescue.

scholarly journals Regulation of epidermal growth factor receptor signaling by clathrin-coated membrane microdomains

2021 ◽  
Author(s):  
Camilo Garay
Keyword(s):  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Tyrosine Kinases ◽  
Egf Receptor ◽  
Akt Signaling ◽  
Membrane Microdomains ◽  
Egfr Signaling ◽  
Coated Pits ◽  
Akt Phosphorylation ◽  
Epidermal Growth

The phosphatidylinositol-3-kinase (PI3K)-Akt signaling axis controls cell survival, proliferation and metabolism, and is activated by receptor tyrosine kinases (RTKs) such as the epidermal growth factor (EGF) receptor (EGFR). In addition to activation of PI3K-Akt signaling, the binding of EGF to its receptor results in rapid recruitment of EGFR to clathrin-coated pits (CCPs) followed by eventual EGFR internalization. Hence, receptor-proximal activation of signaling intermediates occurs while EGFR resides within CCPs; however, whether CCPs are required for EGFR signaling remains poorly understood. Using a combination of pharmacological inhibition and siRNA gene silencing of clathrin, we have examined how clathrin controls EGF-stimulated activation of Akt. We find that perturbation of clathrin, but not of EGFR endocytosis by perturbation of dynamin leads to disruption of EGF-stimulated Akt phosphorylation. This indicates that clathrin acts in a function separate from its role in endocytosis to regulate EGFR signaling at the plasma membrane. The EGF-stimulated phosphorylation of the signaling intermediate Gab1, but not that of EGFR itself, was also abrogated upon disruption of clathrin. We then utilized total internal reflection fluorescence microscopy (TIRF-M) to examine the hierarchy of recruitment of EGFR signaling components to CCPs. Collectively, these findings suggest a role for clathrin as a central regulator of EGFR signaling leading to Gab1 and Akt phosphorylation.

scholarly journals Cell fate patterning during C. elegans vulval development

Development ◽  
1993 ◽  
Vol 119 (Supplement) ◽  
pp. 9-18 ◽  
Author(s):  
Russell J. Hill ◽  
Paul W. Sternberg
Keyword(s):  
Cell Fate ◽  
Short Range ◽  
Precursor Cells ◽  
Cell Fates ◽  
Vulval Development ◽  
C Elegans ◽  
Vulval Precursor Cells ◽  
Combined Action ◽  
Anchor Cell ◽  
Inductive Signal

Precursor cells of the vulva of the C. elegans hermaphrodite choose between two vulval cell fates (1° and 2°) and a non-vulval epidermal fate (3°) in response to three intercellular signals. An inductive signal produced by the anchor cell induces the vulval precursors to assume the 1° and 2° vulval fates. This inductive signal is an EGF-like growth factor encoded by the gene lin-3. An inhibitory signal mediated by lin-15, and which may originate from the surrounding epidermis, prevents the vulval precursors from assuming vulval fates in the absence of the inductive signal. A short range lateral signal, which acts through the gene lin-12, regulates the pattern of 1° and 2° fates assumed by the induced vulval precursors. The combined action of the three signals precisely directs the six vulval precursors to adopt a 3° 3° 2° 1° 2 ° 3° pattern of fates. The amount of inductive signal produced by the anchor cell appears to determine the number or vulval precursors that assume vulval fates. The three induced vulval precursors most proximal to the anchor cell are proposed to adopt the 2° 1° 2° pattern of fates in response to a gradient of the inductive signal and also in response to lateral signalling that inhibits adjacent vulval precursor cells from both assuming the 1° fate.

Sign in / Sign up

Export Citation Format

Share Document