Effects of beta subunit cytoplasmic domain deletions on the recruitment of the integrin alpha v beta 6 to focal contacts

Cell Adhes Commun. 1994 Jun;2(2):101-13. doi: 10.3109/15419069409004430.

Abstract

The integrin alpha v beta 6 is expressed primarily in epithelial cells and mediates attachment to the extracellular matrix protein fibronectin. We recently observed that alpha v beta 6 localizes to focal contacts when cells that express the receptor are plated on fibronectin. To determine which regions of the beta 6 cytoplasmic domain are required for recruitment to focal contacts, the wild type human beta 6 cytoplasmic domain are required for recruitment to focal contacts, the wild type human beta 6 subunit and mutants containing selective deletions within the beta 6 cytoplasmic domain were stably expressed in Chinese Hamster Ovary cells. The beta 6 cytoplasmic domain is composed of a 41 amino acid region that is highly conserved among integrin beta subunits, and a unique 11 amino acid carboxy terminal extension. The 11 amino acid extension was not required for localization to focal contacts; in fact, its removal appeared to increase receptor localization. However, removal of any of the 3 conserved regions previously identified as important for the localization of beta 1 integrins to focal contacts (Reszka, et al., 1992, J. Cell Biol. 117:1321-30) eliminated recruitment of beta 6 to focal contacts. These data suggest that, as with the integrin beta 1 subunit, multiple regions within the first 41 amino acids of the beta 6 cytoplasmic domain are necessary for recruitment of alpha v beta 6 to focal contacts. However, the unique 11 amino acid carboxy terminus of beta 6 is not required for this recruitment, and may actually play a negative regulatory role.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Actins / metabolism
  • Amino Acid Sequence
  • Animals
  • Antigens, Neoplasm*
  • Binding Sites
  • CHO Cells
  • Cell Adhesion / physiology*
  • Clathrin / metabolism
  • Cricetinae
  • Cytoplasm / metabolism
  • Fluorescent Antibody Technique
  • Humans
  • Integrins / chemistry
  • Integrins / genetics*
  • Integrins / physiology*
  • Molecular Sequence Data
  • Sequence Deletion
  • Transfection
  • Vinculin / metabolism

Substances

  • Actins
  • Antigens, Neoplasm
  • Clathrin
  • Integrins
  • integrin alphavbeta6
  • Vinculin