An official website of the United States government
Across species, Epidermal Growth Factor (EGF) family ligands and their receptors participate in developmental and physiological cell-cell signaling events. C. elegans possesses a single EGF receptor, LET-23/EGFR, and two characterized EGF ligands. LIN-3/EGF is well-known for its role in vulval induction, and SISS-1/EGF mediates stress-induced sleep. The C. elegans genome harbors another predicted EGF family member, igeg-2, which has not been characterized. To determine if IGEG-2 is a functional EGFR ligand, we examined whether it can activate known LET-23-dependent processes. We found that ubiquitous overexpression of IGEG-2 promotes both vulval induction and sleep, indicating that it is a functional EGF family ligand. The endogenous role of IGEG-2 remains unknown.
more »
« less
The tyrosine kinase inhibitor Gefitinib reduces C. elegans stress-induced sleep, but not likely via LET-23/EGFR inhibition
The anticancer drug Gefitinib is a tyrosine kinase inhibitor with selectivity for the Epidermal Growth Factor Receptor (EGFR/ErbB1). As the C. elegans EGF receptor LET-23 shares notable structural homology over its kinase domain with human EGFR, we wished to examine whether Gefitinib treatment can interfere with LET-23-dependent processes. We show that Gefitinib disrupts C. elegans stress-induced sleep (SIS) but does not impact EGF overexpression-induced sleep nor vulva induction. These findings indicate that Gefitinib does not interfere with LET-23 signaling and impairs SIS through an off-target mechanism.
more »
« less
- Award ID(s):
- 2216486
- PAR ID:
- 10544090
- Publisher / Repository:
- microPublication Biology
- Date Published:
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
More Like this
-
-
Sleep is ancient and genetically conserved across phylogeny. Neuropeptide signaling plays a fundamental role in the regulation of sleep for mammals, fish, and invertebrates like Caenorhabditis elegans. Developmentally timed-sleep and stress-induced sleep of C. elegans are controlled by distinct and overlapping neuropeptide pathways. The RPamide neuropeptides nlp-2, nlp-22, and nlp-23, play antagonistic roles during the regulation of developmentally-timed sleep, however, their role in stress-induced sleep has not been explored. These genes are linked on the X chromosome, which has made genetic analyses challenging. Here we used CRISPR to generate new alleles of nlp-22 and nlp-23, nlp-22;nlp-23 double mutants, and nlp-2;nlp-22;nlp-23 triple mutants. Confirming previous studies, we find that nlp-22 is required for developmentally-timed sleep, and show that nlp-23 is also required. However, all three genes are dispensable for stress-induced sleep.more » « less
-
Orcokinin neuropeptides are conserved among ecdysozoans, but their functions are incompletely understood. Here, we report a role for orcokinin neuropeptides in the regulation of sleep in the nematode Caenorhabditis elegans. The C. elegans orcokinin peptides, which are encoded by the nlp-14 and nlp-15 genes, are necessary and sufficient for quiescent behaviors during developmentally timed sleep (DTS) as well as during stress-induced sleep (SIS). The five orcokinin neuropeptides encoded by nlp-14 have distinct but overlapping functions in the regulation of movement and defecation quiescence during SIS. We suggest that orcokinins may regulate behavioral components of sleep-like states in nematodes and other ecdysozoans.more » « less
-
Abstract Mechanistic understanding of oncogenic variants facilitates the development and optimization of treatment strategies. We recently identified in-frame, tandem duplication ofEGFRexons 18 - 25, which causes EGFR Kinase Domain Duplication (EGFR-KDD). Here, we characterize the prevalence ofERBBfamily KDDs across multiple human cancers and evaluate the functional biochemistry of EGFR-KDD as it relates to pathogenesis and potential therapeutic intervention. We provide computational and experimental evidence that EGFR-KDD functions by forming asymmetric EGF-independent intra-molecular and EGF-dependent inter-molecular dimers. Time-resolved fluorescence microscopy and co-immunoprecipitation reveals EGFR-KDD can form ligand-dependent inter-molecular homo- and hetero-dimers/multimers. Furthermore, we show that inhibition of EGFR-KDD activity is maximally achieved by blocking both intra- and inter-molecular dimerization. Collectively, our findings define a previously unrecognized model of EGFR dimerization, providing important insights for the understanding of EGFR activation mechanisms and informing personalized treatment of patients with tumors harboring EGFR-KDD. Finally, we establishERBBKDDs as recurrent oncogenic events in multiple cancers.more » « less
-
The epidermal growth factor receptor (EGFR) is a receptor tyrosine kinase (RTK) commonly targeted for inhibition by anticancer therapeutics. Current therapeutics target EGFR’s kinase domain or extracellular region. However, these types of inhibitors are not specific for tumors over healthy tissue and therefore cause undesirable side effects. Our lab has recently developed a new strategy to regulate RTK activity by designing a peptide that specifically binds to the transmembrane (TM) region of the RTK to allosterically modify kinase activity. These peptides are acidity-responsive, allowing them to preferentially target acidic environments like tumors. We have applied this strategy to EGFR and created the PET1 peptide. We observed that PET1 behaves as a pH-responsive peptide that modulates the configuration of the EGFR TM through a direct interaction. Our data indicated that PET1 inhibits EGFR-mediated cell migration. Finally, we investigated the mechanism of inhibition through molecular dynamics simulations, which showed that PET1 sits between the two EGFR TM helices; this molecular mechanism was additionally supported by AlphaFold-Multimer predictions. We propose that the PET1-induced disruption of native TM interactions disturbs the conformation of the kinase domain in such a way that it inhibits EGFR’s ability to send migratory cell signals. This study is a proof-of-concept that acidity-responsive membrane peptide ligands can be generally applied to RTKs. In addition, PET1 constitutes a viable approach to therapeutically target the TM of EGFR.more » « less
- Free Publicly Accessible Full Text
-
Accepted Manuscript1.0
- Data Paper:
- https://doi.org/10.17912/micropub.biology.001138
