Genetic analysis of the sevenless signal transduction pathway of Drosophila

Development ◽  
1993 ◽  
Vol 119 (Supplement) ◽  
pp. 41-46 ◽  
Author(s):  
E. Hafen ◽  
B. Dickson ◽  
T. Raabe ◽  
D. Brunner ◽  
N. Oellers ◽  
...  
Keyword(s):  
Signal Transduction ◽  
Cell Fate ◽  
Receptor Tyrosine Kinase ◽  
Photoreceptor Cell ◽  
Signal Transduction Pathway ◽  
Signal Transduction Pathways ◽  
Transduction Pathway ◽  
Genetic Screens ◽  
Constitutive Activation

The specification of the R7 photoreceptor cell fate in the developing eye of Drosophila depends on the local activation of the sevenless (sev) receptor tyrosine kinase (RTK) by boss, a protein expressed on the membrane of the neighboring R8 cell. Constitutive activation of the scv receptor results in a dosage dependent increase in the number of R7 cells per ommatidium. Genetic screens have been used to identify mutations that alter the efficiency of signal transduction. Subsequent molecular characterization of the corresponding genes has led to the identification of a number of proteins involved in transducing the signal from the receptor to the nucleus. In contrast to the receptor and its ligand, these components are shared between different signal transduction pathways not only in Drosophila but homologous components are also involved in signal transduction in other organisms.

Genetic dissection of signal transduction mediated by the sevenless receptor tyrosine kinase in Drosophila

1993 ◽  
Vol 340 (1293) ◽  
pp. 273-278 ◽  
Keyword(s):  
Signal Transduction ◽  
Tyrosine Kinase ◽  
Cell Fate ◽  
Receptor Tyrosine Kinase ◽  
Photoreceptor Cell ◽  
Genetic Dissection ◽  
Genetic Screens ◽  
Constitutive Activation ◽  
Sevenless Receptor Tyrosine Kinase

The specification of the R7 photoreceptor cell fate in the developing eye of Drosophila depends on the local activation of the sevenless (Sev) receptor tyrosine kinase by Boss, a protein expressed on the membrane of the neighbouring R8 cell. Constitutive activation of the Sev receptor results in a dosage-dependent increase in the number of R7 cells per ommatidium. Genetic screens have been used to identify mutations that alter the efficiency of signal transduction. Subsequent molecular characterization of the corresponding genes has led to the identification of a number of proteins involved in transducing the signal from the receptor to the nucleus. In contrast to the receptor and its ligand, these components are shared between different signal transduction pathways not only in Drosophila but are also homologous to components involved in signal transduction in other organisms.

scholarly journals Gain-of-Function Mutations in the Caenorhabditis elegans lin-1 ETS Gene Identify a C-Terminal Regulatory Domain Phosphorylated by ERK MAP Kinase

Genetics ◽  
1998 ◽  
Vol 149 (4) ◽  
pp. 1809-1822 ◽  
Author(s):  
Dave Jacobs ◽  
Greg J Beitel ◽  
Scott G Clark ◽  
H Robert Horvitz ◽  
Kerry Kornfeld
Keyword(s):  
Signal Transduction ◽  
Caenorhabditis Elegans ◽  
Tyrosine Kinase ◽  
Map Kinase ◽  
Cell Fate ◽  
Receptor Tyrosine Kinase ◽  
Signal Transduction Pathway ◽  
Negative Regulation ◽  
Transduction Pathway ◽  
C Terminus

Abstract Genetic analysis of lin-1 loss-of-function mutations suggests that lin-1 controls multiple cell-fate decisions during Caenorhabditis elegans development and is negatively regulated by a conserved receptor tyrosine kinase-Ras-ERK mitogen-activated protein (MAP) kinase signal transduction pathway. LIN-1 protein contains an ETS domain and presumably regulates transcription. We identified and characterized six gain-of-function mutations that define a new class of lin-1 allele. These lin-1 alleles appeared to be constitutively active and unresponsive to negative regulation. Each allele has a single-base change that affects the predicted C terminus of LIN-1, suggesting this region is required for negative regulation. The C terminus of LIN-1 was a high-affinity substrate for Erk2 in vitro, suggesting that LIN-1 is directly regulated by ERK MAP kinase. Because mpk-1 ERK MAP kinase controls at least one cell-fate decision that does not require lin-1, our results suggest that MPK-1 contributes to the specificity of this receptor tyrosine kinase-Ras-MAP kinase signal transduction pathway by phosphorylating different proteins in different developmental contexts. These lin-1 mutations all affect a four-amino-acid motif, FQFP, that is conserved in vertebrate and Drosophila ETS proteins that are also phosphorylated by ERK MAP kinase. This sequence may be a substrate recognition motif for the ERK subfamily of MAP kinases.

The Phosphoinositide Signal Transduction Pathway in the Pathogenesis of Alzheimer’s Disease

2018 ◽  
Vol 15 (4) ◽  
pp. 355-362 ◽  
Author(s):  
Vincenza Rita Lo Vasco
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Signal Transduction ◽  
Membrane Trafficking ◽  
Hormone Secretion ◽  
Signal Transduction Pathway ◽  
Brain Morphology ◽  
Signal Transduction Pathways ◽  
Transduction Pathway ◽  
Cell Functions

Background: During aging and in age-associated disorders, such as Alzheimer's Disease (AD), learning abilities decline. Probably, disturbances in signal transduction in brain cells underlie the cognitive decline. The phosphorylation/dephosphorylation imbalance occurring in degenerating neurons was recently related to abnormal activity of one or more signal transduction pathways. AD is known to be associated with altered neuronal Ca<sup>2+</sup> homeostasis, as Ca<sup>2+</sup> accumulates in affected neurons leading to functional impairment. It is becoming more and more evident the involvement of signal transduction pathways acting upon Ca<sup>2+</sup> metabolism and phosphorylation regulation of proteins. A growing interest raised around the role of signal transduction systems in a number of human diseases including neurodegenerative diseases, with special regard to the systems related to the phosphoinositide (PI) pathway and AD. The PI signal transduction pathway plays a crucial role, being involved in a variety of cell functions, such as hormone secretion, neurotransmitter signal transduction, cell growth, membrane trafficking, ion channel activity, cytoskeleton regulation, cell cycle control, apoptosis, cell and tissue polarity, and contributes to regulate the Ca<sup>2+</sup> levels in the nervous tissue. Conclusion: A number of observations indicated that PI-specific phospholipase C (PLC) enzymes might be involved in the alteration of neurotransmission. To understand the role and the timing of action of the signalling pathways recruited during the brain morphology changes during the AD progression might help to elucidate the aetiopathogenesis of the disease, paving the way to prognosis refinement and/or novel molecular therapeutic strategies.

Abstract 741: Characterization of high-grade serous ovarian carcinoma by measuring functional signal transduction pathway activity

2021 ◽  
Author(s):  
Phyllis van der Ploeg ◽  
Laura van Lieshout ◽  
Yvonne Wesseling-Rozendaal ◽  
Anja van de Stolpe ◽  
Diederick Keizer ◽  
...  
Keyword(s):  
Signal Transduction ◽  
Ovarian Carcinoma ◽  
Signal Transduction Pathway ◽  
High Grade ◽  
Transduction Pathway ◽  
Pathway Activity ◽  
Serous Ovarian Carcinoma

scholarly journals Genetic evidence for signal transduction within the Bacillus subtilis GerA germinant receptor

2021 ◽  
Author(s):  
Jeremy D. Amon ◽  
Lior Artzi ◽  
David Z. Rudner
Keyword(s):  
Signal Transduction ◽  
Bacillus Subtilis ◽  
Signal Transduction Pathway ◽  
Dominant Negative ◽  
Transduction Pathway ◽  
Sense And Respond ◽  
Enrichment Strategy ◽  
Functional Receptor

Bacterial spores can rapidly exit dormancy through the process of germination. This process begins with the activation of nutrient receptors embedded in the spore membrane. The prototypical germinant receptor in Bacillus subtilis responds to L-alanine and is thought to be a complex of proteins encoded by the genes in the gerA operon: gerAA , gerAB , and gerAC . The GerAB subunit has recently been shown to function as the nutrient sensor, but beyond contributing to complex stability, no additional functions have been attributed to the other two subunits. Here, we investigate the role of GerAA. We resurrect a previously characterized allele of gerA (termed gerA* ) that carries a mutation in gerAA and show it constitutively activates germination even in the presence of a wild-type copy of gerA . Using an enrichment strategy to screen for suppressors of gerA* , we identified mutations in all three gerA genes that restore a functional receptor. Characterization of two distinct gerAB suppressors revealed that one ( gerAB[E105K]) reduces the GerA complex's ability to respond to L-alanine, while another ( gerAB[F259S] ) disrupts the germinant signal downstream of L-alanine recognition. These data argue against models in which GerAA is directly or indirectly involved in germinant sensing. Rather, our data suggest that GerAA is responsible for transducing the nutrient signal sensed by GerAB. While the steps downstream of gerAA have yet to be uncovered, these results validate the use of a dominant-negative genetic approach in elucidating the gerA signal transduction pathway. Importance Endospore formers are a broad group of bacteria that can enter dormancy upon starvation and exit dormancy upon sensing the return of nutrients. How dormant spores sense and respond to these nutrients is poorly understood. Here, we identify a key step in the signal transduction pathway that is activated after spores detect the amino acid L-alanine. We present a model that provides a more complete picture of this process that is critical for allowing dormant spores to germinate and resume growth.

Characterization of the ABA signal transduction pathway in Vitis vinifera

Plant Science ◽  
2012 ◽  
Vol 187 ◽  
pp. 89-96 ◽  
Author(s):  
Uri Boneh ◽  
Iris Biton ◽  
Amnon Schwartz ◽  
Giora Ben-Ari
Keyword(s):  
Signal Transduction ◽  
Vitis Vinifera ◽  
Signal Transduction Pathway ◽  
Transduction Pathway ◽  
Aba Signal Transduction
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