ABSTRACT
Data-processing protein networks are continuously reorganized both spatially and temporally. Biological data processing—even if based on the same mathematical principles—is certainly more ingenious and sophisticated than today's computer technology, and it is still far from clear whether it can ever be interpreted and imitated by a technological approach. When compared with the computer metaphor, however, the "brain of the cell" concept has a clear advantage: it emphasizes the strong resemblance of biological data processing at levels of different complexity. Impressive microscopic photographs and three-dimensional models showing the beauty and complexity of the neuronal network in the brain have given a vivid impression of the cross talk between nerve cells. The term signal transduction has become established for the molecular mechanisms by which cells process information transmitted by exogenous or endogenous stimuli. As a rule, signal transducing proteins have many more interaction modules than other proteins such as metabolic enzymes.
