Cell Signaling-ICAM-1, Integrin, Nucleolin

Intercellular Adhesion Molecule-1 (ICAM-1)

ICAM-1 binds the leukocyte integrins LFA-1 and Mac-1. ICAM-1 expression is weak on leukocytes, epithelial and resting endothelial cells, as well as some other cell types, but expression can be stimulated by IFN-gamma, TNF-alpha, IL-1 beta and LPS. Soluble ICAM-1 is found in a biologically active form in serum, probably as a result of proteolytic cleavage from the cell surface, and is elevated in patients with various inflammatory syndromes such as septic shock, LAD, cancer and transplantation.

Integrin

Integrins are a large family of heterodimeric receptors important for cell adhesion and signaling. Integrin heterodimers, which consist of an alpha subunit and a beta subunit, are type-I transmembrane receptors that play vital roles in immune response, cell motility, cell-matrix interactions, signaling, proliferation, and apoptosis.

 Nucleolin

Nucleolin is an abundant 77 kDa RNA binding protein found in the nucleolus of all eukaryotic cells, and is involved in rRNA packaging and transport. This protein is composed of three main structural domains. It functions for viral attachment or entry, NF-kB signaling and induction of tumor suppressor gene expression, etc.