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Author Notes:

To whom correspondence should be addressed: G.M. Benian Dept. of Pathology, Whitehead Bldg. 105E, Emory University, 615 Michael St., Atlanta, GA 30322. Tel.: 404-727-5953; Fax: 404-727-8538; E-mail: pathgb@emory.edu.

We thank Andy Fire (Stanford University) for C. elegans expression vectors and Kozo Kaibuchi (Nagoya University) for bacterial and yeast expression vectors.

Subjects:

Research Funding:

This study was supported by American Heart Association Grant 11GRNT7820000.

Keywords:

  • Science & Technology
  • Life Sciences & Biomedicine
  • Biochemistry & Molecular Biology
  • BIOCHEMISTRY & MOLECULAR BIOLOGY
  • Adhesion
  • C elegans
  • Muscle
  • Protein Structure
  • Protein-Protein Interactions
  • Integrin-linked Kinase
  • Kindlin
  • Suppressor Genetics
  • CAENORHABDITIS-ELEGANS MUSCLE
  • CELL-MATRIX ADHESIONS
  • FOCAL ADHESIONS
  • UCSF CHIMERA
  • LOCALIZATION
  • COMPLEXES
  • PROTEINS
  • UNC-97/PINCH
  • COMPONENTS
  • SITES

Suppressor Mutations Suggest a Surface on PAT-4 ( Integrin-linked Kinase) That Interacts with UNC-112 ( Kindlin)

Tools:

Journal Title:

Journal of Biological Chemistry

Volume:

Volume 289, Number 20

Publisher:

, Pages 14252-14262

Type of Work:

Article | Final Publisher PDF

Abstract:

Caenorhabditis elegans striated muscle cells attach to basement membrane and transmit the force of muscle contraction through integrin adhesion complexes. The cytoplasmic tail of β-integrin (PAT-3) is associated with a conserved four-protein complex that includes UNC-112 (kindlin), PAT-4 (integrinlinked kinase), PAT-6 (α-parvin/actopaxin), and UNC-97 (PINCH). The proper localization of UNC-112 to muscle integrin adhesion sites requires PAT-4. A recent report (Qadota, H., Moerman, D. G., and Benian, G. M. (2012) A molecular mechanism for the requirement of PAT-4 (integrin-linked kinase (ILK)) for the localization of UNC-112 (kindlin) to integrin adhesion sites. J. Biol. Chem. 287, 28537-28551) suggests a possible molecular mechanism for this requirement: that UNC-112 exists in closed inactive and open active conformations, and conversion to the open active form is promoted by binding to PAT-4 (ILK). Previously, we also reported identification of a single missense mutation in UNC-112, D382V, which abolishes both binding to PAT-4 and normal localization to integrin adhesion sites in vivo. In this report, we describe isolation and characterization of PAT-4 missense mutations that permit binding with UNC-112 D382V and place nine affected residues on a homology model of PAT-4. These nine residues cluster in two regions on the surface of PAT-4, do not overlap the likely binding surface for PAT-6 (α-parvin), and therefore may reside along the interaction surface of PAT-4 for UNC-112 (kindlin). We also show that one of these PAT-4 mutations restores the ability of UNC-112 D382V to localize to integrin adhesions and participate in complex formation.

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© 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

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