Figure 1.

Gravi-sensitive signal transduction elements in mammalian cells. Gravi-sensitive signal transduction elements has been detected at the cell surface, such as VCAM-1 (Vascular cell adhesion molecule 1), ICAM-1 (Intercellular adhesion and molecule 1) and IL-2R (interleukin-2 receptor), in the cytoplasma such as PKC (protein kinase C) and MAPK (mitogen-activated protein kinases) and in the nucleus such as expression of c-fos, c-jun and other genes. Microgravity severely affects also the cytoskeleton. However, the primary molecular mechanisms how microgravity influences cell signaling are unknown.