What does the sevenless gene do?
By Rachel Newton
What does the sevenless gene do?
Sevenless (sev) is a gene in Drosophila melanogaster that encodes a receptor tyrosine kinase protein essential to the development of R7 cells in the Drosophila embryonic eye. The R7 photo receptor, located in each of several ommatidium in the fly’s compound eye, is used to detect ultraviolet light.
What is sevenless signalling?
Sevenless is a membrane-spanning receptor with an intracellular tyrosine kinase domain that signals in a way that closely resembles the signaling by hormone receptors such as the insulin receptor tyrosine kinase.
What would happen to R7 development in a sevenless fruit fly if you deleted boss from its genome?
Removal of the R7 cells in sevenless, boss or sina mutants, disrupts Rh5 expression and dramatically increases the number of Rh6-expressing R8 cells.
What is bride of sevenless?
During development of the Drosophila retina, the bride of sevenless (boss) gene is required in photoreceptor neuron R8 for the development of photoreceptor neuron R7, suggesting that boss encodes or regulates an R7-specific inductive cue. .
Why is son of Sevenless?
The gene was so named because the Sos protein that it encoded was found to operate downstream of the sevenless gene in Drosophila melanogaster in a Ras/MAP kinase pathway. Similarly, the mammalian orthologues of Sos, SOS1 and SOS2, function downstream of many growth factor and adhesion receptors.
What is the function of the src protein?
Src is a non-receptor protein tyrosine kinase that transduces signals that are involved in the control of a variety of cellular processes such as proliferation, differentiation, motility, and adhesion.
How is it possible for the activation of Ras to lead to transcription of different sets of genes in the two different cell types?
This activated Ras can activate a signal transduction cascade, which ultimately results in the transcription of genes required for R7 differentiation. In different cells in the same animal, Ras can be activated by an activated growth factor receptor. This leads to transcription of genes required for cell division.
Is son of Sevenless a GEF?
Son of sevenless (Sos) is a dual specificity guanine nucleotide exchange factor (GEF) that regulates both Ras and Rho family GTPases and thus is uniquely poised to integrate signals that affect both gene expression and cytoskeletal reorganization.
Is Grb2 a kinase?
Grb2 is widely expressed and is essential for multiple cellular functions. Grb2 is best known for its ability to link the epidermal growth factor receptor tyrosine kinase to the activation of Ras and its downstream kinases, ERK1,2. Grb2 is composed of an SH2 domain flanked on each side by an SH3 domain.
How do GRB2 and SOS activate Ras?
After growth factor stimulation, the tyrosine phosphorylated EGF receptor binds the Grb2/Sos complex, translocating it to the plasma membrane. This translocation is thought to bring Sos into close proximity with Ras, leading to the activation of Ras.
