The role of the small GTPase Rap in Drosophila R7 photoreceptor specification
Autor: | Yannis Emmanuel Mavromatakis, Andrew Tomlinson |
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Rok vydání: | 2012 |
Předmět: |
Cell Cycle Proteins
Cell fate determination Models Biological Cdh1 Proteins Receptor tyrosine kinase Transduction (genetics) Animals Drosophila Proteins Cell Lineage Small GTPase Transcription factor Alleles Crosses Genetic Monomeric GTP-Binding Proteins Recombination Genetic Multidisciplinary Receptors Notch biology fungi Epistasis Genetic Genomics Biological Sciences biology.organism_classification Cell biology Drosophila melanogaster ras Proteins biology.protein Photoreceptor Cells Invertebrate sense organs Signal transduction Drosophila Protein Signal Transduction Transcription Factors |
Zdroj: | Proceedings of the National Academy of Sciences. 109:3844-3849 |
ISSN: | 1091-6490 0027-8424 |
Popis: | The Drosophila R7 photoreceptor provides an excellent model system with which to study how cells receive and “decode” signals that specify cell fate. R7 is specified by the combined actions of the receptor tyrosine kinase (RTK) and Notch (N) signaling pathways. These pathways interact in a complex manner that includes antagonistic effects on photoreceptor specification: RTK promotes the photoreceptor fate, whereas N inhibits. Although other photoreceptors are subject to only mild N activation, R7 experiences a high-level N signal. To counter this effect and to ensure that the cell is specified as a photoreceptor, a high RTK signal is transduced in the cell. Thus, there are two levels of RTK transduction in the photoreceptors: in R7 it is high, whereas in others it is low. Here, we address how this high-level RTK signal is transduced in R7 and find that, in addition to Ras, another small GTPase, Rap, is also engaged. Thus, when N activity is high, a robust RTK signal operates that uses both Ras and Rap, but when N activity is low, only a mild RTK signal is transduced and Ras alone suffices for the purpose. |
Databáze: | OpenAIRE |
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