A Hox complex activates and potentiates the Epidermal Growth Factor signaling pathway to specify Drosophila oenocytes
Year: 2017
Type: article
Abstract: Hox transcription factors specify distinct cell types along the anterior-posterior axis of metazoans by regulating target genes that modulate signaling pathways.A well-established example is the induction of Epidermal Growth Factor (EGF) signaling by an Abdominal-A (Abd-A) Hox complex during the specification of Drosophila hepatocyte-like cells (oenocytes).Previous studies revealed that Abd-A is non-cell autonomously required to promote oenocyte fate by directly activating a gene (rhomboid) that triggers EGF secretion from sensory organ precursor (SOP) cells.Neighboring cells that receive the EGF signal initiate a largely unknown pathway to promote oenocyte fate.Here, we show that Abd-A also plays a cell autonomous role in inducing oenocyte fate by activating the expression of the Pointed-P1 (PntP1) ETS transcription factor downstream of EGF signaling.Genetic studies demonstrate that both PntP1 and PntP2 are required for oenocyte specification.Moreover, we found that PntP1 contains a conserved enhancer (PntP1OE) that is activated in oenocyte precursor cells by EGF signaling via direct regulation by the Pnt transcription factors as well as a transcription factor complex consisting of Abd-A, Extradenticle, and Homothorax.Our findings demonstrate that the same Abd-A Hox complex required for sending the EGF signal from SOP cells, enhances the competency of receiving cells to select oenocyte cell fate by up-regulating PntP1.Since PntP1 is a downstream effector of EGF signaling, these findings provide insight into how a Hox factor can both trigger and potentiate the EGF signal to promote an essential cell fate along the body plan. Author summaryHox genes encode a conserved family of transcription factors that regulate unique cell types within the distinct morphological structures that arise along the body plan of animals.Hox transcription factors specify different cell fates by regulating the expression of downstream genes, many of which are part of cell signaling pathways.For example, a Hox factor that is only expressed in the Drosophila abdomen (Abdominal-A) activates the release of a signaling molecule (Epidermal Growth Factor, EGF) from a specific neural precursor cell.The cells that receive the signal are induced to become essential hepatocyte-
Source: PLoS Genetics
Institution: Cincinnati Children's Hospital Medical Center
Language: English
Subfield: Molecular Biology
Domain: Life Sciences
Open Access status: gold
Estimated APC paid: $3,043
OpenAlex ID: W2735833462