Biosciences Research Seminar - Epithelial polarity and the response to stretching

Most of our tissue and organs are composed of cells that adhere to each other to form epithelial sheets and tubes that act as a barriers between our insides and the outside world. To form these sheets, all cells must first polarise in the same direction, with their apical surfaces facing outside and their lateral sides forming specialised junctions. Furthermore, about 80% of tumours arise from epithelial tissues and one of their hallmarks is defects in apical-basal polarity. Work over the past 20 years has defined a conserved set of polarity factors that define the apical, junctional and lateral domains of epithelial cells, but how these specify each domain and control the polarised organisation of the cytoskeleton and membrane trafficking pathways is currently unknown. My talk will describe how acute inhibition of a key apical polarity factor and oncogene, atypical protein kinase C, reveals that our current model of epithelial polarity is incorrect and uncovers a novel homeostatic pathway that controls the epithelial response to mechanical stretching.