DICAM, a novel dual immunoglobulin domain containing cell adhesion molecule interacts with alphavbeta3 integrin

• Published in: Journal of cellular physiology 2008-09, Vol.216 (3), p.603-614
• Main Authors: Jung, Youn-Kwan, Jin, Jung-Suk, Jeong, Jae-Hwan, Kim, Hyun-Nam, Park, Na-Rae, Choi, Je-Yong
• Format: Article
• Language: English
• Subjects: Amino Acid Sequence; Animals; Cell Adhesion - physiology; Cell Adhesion Molecules - classification; Cell Adhesion Molecules - genetics; Cell Adhesion Molecules - metabolism; Cell Line; Humans; Immunoglobulins - metabolism; Integrin alphaVbeta3 - genetics; Integrin alphaVbeta3 - metabolism; Membrane Proteins - classification; Membrane Proteins - genetics; Membrane Proteins - metabolism; Molecular Sequence Data; Phylogeny; Protein Structure, Tertiary; Sequence Alignment; Tissue Distribution
• ISSN: 1097-4652
• DOI: 10.1002/jcp.21438

Immunoglobulin (Ig) superfamily members are abundant with diverse functions including cell adhesion in various tissues. Here, we identified and characterized a novel adhesion molecule that belongs to the CTX protein family and named as DICAM (Dual Ig domain containing cell adhesion molecule). DICAM is a type I transmembrane protein with two V-type Ig domains in the extracellular region and a short cytoplasmic tail of 442 amino acids. DICAM is found to be expressed ubiquitously in various organs and cell lines. Subcellular localization of DICAM was observed in the cell-cell contact region and nucleus of cultured epithelial cells. Cell-cell contact region was colocalized with tight junction protein, ZO-1. The DICAM increased MDCK cell adhesion to 60% levels of fibronectin. DICAM mediated cell adhesion was specific for the alphavbeta3 integrin; other integrins, alpha2, alpha5, beta1, alpha2beta1, alpha5beta1, were not involved in cell adhesion. In identifying the interacting domain of DICAM with alphavbeta3, the Ig domain 2 showed higher cell adhesion activity than that of Ig domain 1. Although RGD motif in Ig domain 2 was engaged in cell adhesion, it was not participated in DICAM-alphavbeta3 mediated cell adhesion. Furthermore, differentially expressing DICAM stable cells showed well correlated cell to cell adhesion capability with integrin beta3-overexpressing cells. Collectively, these results indicate that DICAM, a novel dual Ig domain containing adhesion molecule, mediates cell adhesion via alphavbeta3 integrin.