S 100 A 13 mediates the copper - dependent stress - induced release of IL - 1 α from both human U 937 and murine NIH 3 T 3 cells

The prototype members of the IL-1 gene family are well recognized for their inflammatory and angiogenic activities in IL-1α and IL-1β are initially synthesized as precursor proteins and, whereas IL-1α is processed to its mature form by calpain, IL-1β is processed by an aspartate-specific protease from the caspase family termed the IL-1β-converting enzyme (Kobayashi et al., 1990; Kostura et al., 1989). Although these cytokines exert their biological function through high affinity receptors, these prototypes lack a signal peptide sequence to direct their export through the classical secretion pathway mediated by the endoplasmic reticulum-Golgi apparatus (Lomedico et al., 1984). Surprisingly, crystallographic studies have demonstrated that, despite their unremarkable sequence similarities (Thomas et al., 1985), the IL-1 prototypes exhibit a high level of structural homology with the pro-angiogenic signal peptide-less prototype members of the FGF gene family (Carter et al.