Genetic dissection of scaffold protein function in Drosophila

点击翻译按钮获取中文摘要

The organisation of tissues, and effective communication between cells requires that cells become polarised - that is, the cell surface on one side is molecularly different from the other. There is a complicated hierarchy of events that target and then retain specialised signaling or adhesion molecules to certain domains of the cell surface. We seek to understand how this polarisation is maintained, and how it regulates signaling between cells.   Our research program examines two scaffolding proteins, Veli(LIN7) and "Protein Associated with Lin7"(PALS2), that tether cell surface molecules in specialised domains, and link them to the cell's internal skeleton. We are using the genetic model organism, the fruitfly, to manipulate the function of these two proteins, and determine how they perform their function in localising cell surface proteins. We apply genetic approaches to modify protein structure or expression in subsets of cells, and then monitor the consequences in cell morphology and function.   Our previous work has established that Veli is required presynaptically to regulate effective transmitter release. Our working hypothesis is that Veli acts in a scaffold that localises voltage dependent channels at the synapse. We will use a genetic approach to test candidate presynaptic  proteins for a requirement of Veli for efficient targeting and neuromuscular transmission.  We will apply a yeast-2-hybrid approach to uncover which transmembrane proteins bind to Veli at the synapse.   PALS2 works in sheets of cells, in a way that may suppress the growth of cells in tumours. We are extending our analysis of the Veli scaffold to follicle cells, where PALS2 is expressed. Our working hypothesis is that Veli and PALS2 work together in epithelia to localize an  unidentified signaling complex. We will use genetic mosaics, RNAi knockdown and targeted gene expression to characterize the function of Veli and PALS2 in this model epithelium.