dEHBP1 controls exocytosis and recycling of Delta during asymmetric divisions

Abstract

Drosophila EHBP1 is a novel regulator of Notch signaling that may function as an adaptor protein during the exocytosis and recycling of the Notch ligand Delta.

dEHBP1 regulates Scabrous secretion during Notch mediated lateral inhibition

“…dEHBP1 affects eye development dEHBP1 controls Notch signaling during the development of ESO lineages where it controls the abundance and subcellular localization of Sanpodo (Spdo) and Delta (Dl) (Giagtzoglou et al, 2012). To explore whether dEHBP1 regulates Notch signaling in developmental processes other than the asymmetric divisions of the mechanosensory bristle lineages, we generated homozygous mutant clones of loss of function alleles of dEHBP1 in several tissues that depend on Notch signaling for their proper development, using the FLP/FRT technique (Xu and Rubin, 1993).…”

“…While dEHBP1 regulates Notch signaling in the asymmetrically dividing mechanoreceptors via Dl and Spdo (Giagtzoglou et al, 2012), dEHBP1 controls Notch signaling during lateral inhibition in the developing eye via intracellular trafficking and exocytosis of Scabrous, a protein required for lateral inhibition. Our findings emphasize that regulators of intracellular trafficking like dEHBP1 modulate the output of distinct developmental modes of Notch signaling by controlling the intracellular trafficking of different components of the pathway.…”

“…We have recently reported that dEHBP1 regulates Notch signaling in asymmetrically dividing external sensory organ lineages (ESO) (Giagtzoglou et al, 2012). In this context, dEHBP1 controls the abundance of Sanpodo (Spdo), a regulator of Notch signaling (Couturier et al, 2012;Dye et al, 1998;O'Connor-Giles and Skeath, 2003;Skeath and Doe, 1998), as well as the intracellular trafficking of Delta (Dl), which is the ligand of the Notch receptor (Kimble and Simpson, 1997).…”

“…In this context, dEHBP1 controls the abundance of Sanpodo (Spdo), a regulator of Notch signaling (Couturier et al, 2012;Dye et al, 1998;O'Connor-Giles and Skeath, 2003;Skeath and Doe, 1998), as well as the intracellular trafficking of Delta (Dl), which is the ligand of the Notch receptor (Kimble and Simpson, 1997). Interestingly, dEHBP1 physically interacts with both the recycling endosome Rab11 GTPase and its effector, Sec15 (Giagtzoglou et al, 2012). Moreover, Rab11 and Sec15 physically interact (Wu et al, 2005) and regulate Dl trafficking (Emery et al, 2005;Jafar-Nejad et al, 2005) towards the apical portion of the actin-rich structure (ARS), which is the actin-rich plasma membrane microdomain at the interface of the pIIa/pIIb progeny in the ESO lineage, promoted by the activity of the WASP-Arp2/3 actin regulatory complex (Rajan et al, 2009).…”

Regulation of centrosome movements by Numb and the Collapsin Response Mediator Protein during Drosophila sensory progenitor asymmetric division

“…During pI cell division, numerous studies have established the functional importance of Delta recycling in the regulation of cell fate acquisition (Le Borgne, 2006;Le Borgne et al, 2005). In particular, Delta recycling via the basal recycling endosomes and its trafficking towards the apical pI daughter cell interface is essential to the activation of the Notch receptor (Benhra et al, 2011;Benhra et al, 2010;Giagtzoglou et al, 2012;Rajan et al, 2009). Accordingly, the asymmetric Rab11 accumulation around the basally located anterior centrosome has been proposed to play a redundant role to control the activation of Notch signalling (Emery et al, 2005).…”