Cell Adhesion Proteins and a-Fetoprotein. Similar Structural Motifs as Prerequisites for Common Functions
This review is devoted to describing, summarizing and analyzing the data obtained during the last decade and concerning the structural and functional relationships between cell adhesion proteins and alpha-fetoprotein (AFP) which play an important role in embryo- and cancerogenesis demonstrating a synergistic action with growth factors. These are mosaic, multimodular and polyfunctional proteins, each individual module can function independently through binding with specific cell surface receptor. The most of cell adhesion proteins contain EGF-like modules and their repeats which function as signals for cell proliferation, differentiation and survival. Within these EGF-like modules we revealed short motifs similar to the fragment LDSYQCT of human AFP. Such AFP-like motifs in direct and inverted forms are separeted by coasensus octapeptide motif CXXGY/FXGX. AFP-like motifs of cell adhesion proteins together with tripeptide RGD found in AFP may serve as structural prerequisites for common functional features in these groups of unrelated and nonhomologous proteins.