Cell Adhesion Kinase β Forms a Complex with a New Member, Hic-5, of Proteins Localized at Focal Adhesions

• Published in: The Journal of biological chemistry Vol. 273; no. 2; pp. 1003 - 1014
• Main Authors: Matsuya, Manabu, Sasaki, Hiroko, Aoto, Hiroshi, Mitaka, Toshihiro, Nagura, Kazuko, Ohba, Takeaki, Ishino, Masaho, Takahashi, Shuji, Suzuki, Rumiko, Sasaki, Terukatsu
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 09.01.1998
• Subjects: Amino Acid Sequence; Animals; Cell Line; Child, Preschool; Cloning, Molecular; COS Cells; Cytoskeletal Proteins - chemistry; DNA, Complementary; DNA-Binding Proteins - chemistry; DNA-Binding Proteins - genetics; DNA-Binding Proteins - metabolism; Female; Focal Adhesion Kinase 2; Glutathione Transferase - genetics; Humans; Intracellular Signaling Peptides and Proteins; LIM Domain Proteins; Lysophospholipids - pharmacology; Molecular Sequence Data; Oxidative Stress; Paxillin; Phosphoproteins - chemistry; Precipitin Tests; Protein-Tyrosine Kinases - genetics; Protein-Tyrosine Kinases - metabolism; Rats; Recombinant Fusion Proteins - genetics; Recombinant Fusion Proteins - metabolism; Sequence Homology, Amino Acid
• ISSN: 0021-9258; 1083-351X
• DOI: 10.1074/jbc.273.2.1003

Cell adhesion kinase β (CAKβ/PYK2) is the second protein-tyrosine kinase of the focal adhesion kinase subfamily. We identified a cDNA that encodes a CAKβ-binding protein. This cDNA clone encodes the human homologue of Hic-5, the cDNA of which was cloned in 1994 as transforming growth factor β1- and hydrogen peroxide-inducible mRNA. We found that Hic-5 exclusively localized at focal adhesions in a rat fibroblast line, WFB. This localization of Hic-5 was confirmed in WFB cells expressing Myc-tagged Hic-5. The amino acid sequence of Hic-5 is highly similar to that of paxillin in the four LD motifs as well as in the four contiguous LIM domains. The Hic-5 N-terminal domain directly associated in vitrowith the extreme C-terminal region (residue 801 to the end) of CAKβ. CAKβ was coimmunoprecipitated with Hic-5 from the WFB cell lysate. The coimmunoprecipitation of CAKβ with Hic-5 was markedly inhibited by the addition of the extreme C-terminal region of CAKβ. Coimmunoprecipitation of Hic-5 with CAKβ, which was shown in COS-7 cells doubly transfected with cDNA constructs of CAKβ and Myc-tagged Hic-5, was lost when the CAKβ amino acid residues 741–903 were deleted. Hic-5 was tyrosine-phosphorylated in Src-transformed 3Y1 cells and in cells treated with pervanadate. Hic-5 associated with CAKβ was selectively tyrosine-phosphorylated in WFB cells exposed to hypertonic osmotic stress. These results indicate that Hic-5 is a paxillin-related component of focal adhesions and binds to CAKβ, implying possible involvement of Hic-5 in the downstream signaling of CAKβ.