Moesin and Clic Modulate Rhabdomere Morphogenesis in Drosophila melanogaster Photoreceptors
Year: 2013
Type: article
Abstract: The formation of the actin-rich apical surface structures of Drosophila photoreceptor cells, the rhabdomeres, is a tightly regulated process involving many protein interactions.Moesin, the sole Ezrin/Radixin/Moesin (ERM) protein in Drosophila, serves to anchor F-actin microfilaments to the cellular membrane and is subject to many regulatory interactions.Moesin must bind to PIP 2 and then be phosphorylated by the Sterile20 (Ste20) kinase Slik to be activated and serve as a cytoskeletal anchor.Conversely, it is deactivated by dephosphorylation by the PP1 phosphatase PP1-87B.Here I show that the sole CLIC family protein in Drosophila, Clic, is also intimately involved with moesin and PP1-87B in establishing the architecture of rhabdomeres.Disruption in the function of these important proteins has adverse effects on microvilli formation within the rhabdomeres and induces a loss of epithelial integrity and organization within the photoreceptor cells.A knockdown of moesin function causes the loss of three rhabdomeres, two of which can be recovered in a Clic loss-of-function mutant background.This suggests an antagonistic role between Clic and moesin.Masking of the phenotype induced by a knockdown of PP1-87B by the Clic loss-of-function mutation suggests that Clic works upstream of PP1-87B to antagonize moesin function.Our current model is that Clic facilitates the transfer of active moesin from PIP 2 to a membrane protein.Once this transaction is complete, PP1-87B gains access to moesin for dephosphorylation and subsequent deactivation.Thus, I present a model of a novel role for Clic in rhabdomere morphogenesis via genetic interaction with moesin and PP1-87B.
Author: Megan L Ensinger
Institution: Ohio University
Language: English
Subfield: Cell Biology
Domain: Life Sciences
Open Access status: green
OpenAlex ID: W2626867655