Polarity complex proteins

Biochim Biophys Acta. 2008 Mar;1778(3):614-30. doi: 10.1016/j.bbamem.2007.08.029. Epub 2007 Sep 12.


The formation of functional epithelial tissues involves the coordinated action of several protein complexes, which together produce a cell polarity axis and develop cell-cell junctions. During the last decade, the notion of polarity complexes emerged as the result of genetic studies in which a set of genes was discovered first in Caenorhabditis elegans and then in Drosophila melanogaster. In epithelial cells, these complexes are responsible for the development of the apico-basal axis and for the construction and maintenance of apical junctions. In this review, we focus on apical polarity complexes, namely the PAR3/PAR6/aPKC complex and the CRUMBS/PALS1/PATJ complex, which are conserved between species and along with a lateral complex, the SCRIBBLE/DLG/LGL complex, are crucial to the formation of apical junctions such as tight junctions in mammalian epithelial cells. The exact mechanisms underlying their tight junction construction and maintenance activities are poorly understood, and it is proposed to focus in this review on establishing how these apical polarity complexes might regulate epithelial cell morphogenesis and functions. In particular, we will present the latest findings on how these complexes regulate epithelial homeostasis.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Animals
  • Caenorhabditis elegans / cytology
  • Caenorhabditis elegans / genetics
  • Caenorhabditis elegans / physiology
  • Cell Polarity / physiology*
  • Drosophila Proteins / chemistry
  • Drosophila Proteins / genetics
  • Drosophila Proteins / physiology
  • Drosophila melanogaster / cytology
  • Drosophila melanogaster / genetics
  • Drosophila melanogaster / physiology
  • Humans
  • Intercellular Junctions / physiology*
  • Membrane Proteins / chemistry
  • Membrane Proteins / genetics
  • Membrane Proteins / physiology*
  • Models, Biological
  • Molecular Structure
  • Multiprotein Complexes


  • Drosophila Proteins
  • Membrane Proteins
  • Multiprotein Complexes
  • Scrib protein, Drosophila
  • crb protein, Drosophila