Ultrasensitization: switch-like regulation of cellular signaling by transcriptional induction.

ABSTRACT: Cellular signaling networks are subject to transcriptional and proteolytic regulation under both physiological and pathological conditions. For example, the expression of proteins subject to covalent modification by phosphorylation is known to be altered upon cellular differentiation or during carcinogenesis. However, it is unclear how moderate alterations in protein expression can bring about large changes in signal transmission as, for example, observed in the case of haploinsufficiency, where halving the expression of signaling proteins abrogates cellular function. By modeling a fundamental motif of signal transduction, the phosphorylation-dephosphorylation cycle, we show that minor alterations in the concentration of the protein subject to phosphorylation (or the phosphatase) can affec

SUBMITTER: Legewie S 

PROVIDER: S-EPMC1274294 | biostudies-literature | 2005 Oct

REPOSITORIES: biostudies-literature