Although initially characterized as a non-phagocytic adhesion molecule involved in cell-cell interactions [8], [19], [20], these data indicate the involvement of Sn in internalization processes, which may have implications for the understanding of its physiological role.
The first parameter, k15, is involved in internalization processes represented by more than twenty reactions [ 3].
Differences in internalization process into the two cell lines studied explain, in part, the difference in the gene expression.
Intriguingly, Sn lacks obvious tyrosine-based motifs, nevertheless recent data provide evidence for a role of Sn in receptor-mediated internalization processes and show that pathogens that carry sialic acids can be internalized into Sn-expressing macrophages.
Several other endocytic proteins have been found to bind Eps15, including Hrs, STAM, synaptojanin, POB1, α- and γ-adaptin and intersectin, all pointing towards the essential role of Eps15 in secretion and internalization processes (Table 1).
Taken together, our data demonstrate that calcium plays an important role in the internalization process of ligands via surface nucleolin.
In a candidate approach to elucidate the CEACAM1-directed invasin of non-opaque meningococci, we analysed the contribution of NadA and Opc in this internalization process.
Previously we reported that phosphoglycerate kinase (PGK), the well-known glycolytic enzyme, bound to leafhopper actin and was unexpectedly implicated in the internalization process of S. citri into Circulifer haematoceps cells.
The possible role of Sn in an internalization process and its restricted expression pattern on macrophages implicate potential use of this protein in specific macrophage targeting of antigens, toxins, drugs or other molecules, either to specifically eliminate, activate or deactivate macrophages.
The number of endosomes incubated with c-RGD-LPAgNPs reached a platform with 49 ± 9 endosomes observed at the first 3 h, while only very few endosomes (2 3) containing PEG-LPAgNPs were found inside cells during the same time period, suggesting the specific ligand receptor interactions played a key role in the internalization process of NPs.
The similar trends for these parameters suggest membrane perturbation (i.e., "membrane stress") is a clue to the mechanism of grapheme oxide toxicity, in which GO adhesion and internalization processes trigger transport and energetic disorders.
