Partitioning defective 3 homolog (Par3) is an adapter protein involved in asymmetrical cell division and cell polarization processes. It seems to play a central role in the formation of epithelial tight junctions and targets the phosphatase PTEN to cell junctions (By similarity). Par3 association with PARD6B may prevent the interaction of PARD3 with F11R/JAM1, thereby preventing tight junction assembly. The PARD6-PARD3 complex links GTP-bound Rho small GTPases to atypical protein kinase C proteins. Par3 is required for establishment of neuronal polarity and normal axon formation in cultured hippocampal neurons [taken from the Universal Protein Resource (UniProt) www.uniprot.org/uniprot/Q8TEW0].