TITLE:
Interaction of calcium- and integrin-binding protein 1 with integrin α11 and its possible involvement in pulmonary fibrosis
AUTHORS:
Koji Yoshida, Ah-Mee Park, Shingen Ozaki, Hiroshi Munakata
KEYWORDS:
Calcium- and Integrin-Binding Protein 1; Fibrosis; Integrin α11; Yeast Two-Hybrid
JOURNAL NAME:
Advances in Biological Chemistry,
Vol.4 No.1,
February
27,
2014
ABSTRACT: Integrin α11
(ITGA11) is one of the collagen-binding integrin α chains; however, its biological significance remains unknown. To determine
the functions of ITGA11, we performed a yeast two-hybrid screen using the
cytoplasmic domain of ITGA11 as bait and transformed an EGY48 yeast strain with
the bait-containing plasmid using the plasmid from a human lung fibroblast
cDNA library. This screen identified calcium- and integrin-binding protein 1 (CIB1)
as prey. Recombinant ITGA11 and CIB1 were expressed in mammalian cells and
used in coimmunoprecipitation experiments, which showed that full-length
ITGA11 and CIB1 are also associated in
vivo. Over-expression of CIB1 in the human lung myofibroblast MRC-5 cells
decreased the expression of α-smooth
muscle actin and fibronectin. Using a mouse model of pulmonary fibrosis (bleomycin-treatment),
we detected elevated expression of CIB1 in lung tissues compared with
controls. These data suggest that CIB1 may regulate pulmonary fibrosis in
concert with IT-GA11.