Abstract
The PAR3-aPKC-PAR6 complex (the aPKC-PAR complex) is among the most well-studied “polarity proteins” that play fundamental roles in cell polarity in a variety of biological contexts. It is one of the core signaling cassettes containing a protein kinase and scaffold proteins that is conserved in multicellular organisms. One of the most important features of “polarity proteins” is that many of them localize to specific sites on the cytoplasmic side of the cell periphery and position other polarity proteins through antagonistic interactions and positive feedback mechanisms. Asymmetric distribution of polarity proteins in the cell periphery thus provides cellular landmarks required for the generation and maintenance of cell polarity. Here, we describe what we know about the mechanisms of how the aPKC-PAR complex is specifically positioned and activated and regulates overall cell polarity of epithelial cells with special attention to its molecular nature.
