Cell signaling

Abstract

Signal transduction is the molecular process whereby a cell receives, transmits, amplifies, and integrates extracellular stimuli. Key parameters of the signaling pathways are duration and magnitude of the input and subsequent biological responses. Key features of signaling processes include the time- and dose-dependent responses mediated by downstream molecular effectors. The precision of signaling is accomplished through negative feedback and branching between the pathways that mediate cross-talk. Since rate-limiting enzymes in different pathways have different inputs and outputs, integration of signal transduction pathways leads to the optimal biological responses that have been selected during evolution.