Quantify the information capacity of the ERK signaling pathway

Determine the amount of information that the ERK (MAPK/ERK) signaling pathway can carry about graded input stimuli, resolving the discrepancy between prior low population-level estimates and potential single-cell capabilities to transmit more than one bit of information.

Background

Prior studies reported low information content relayed through ERK at the population level, often below 1 bit when considering single features of the response, with modest increases when including dynamics. These conclusions imply limited ability to distinguish the presence or absence of stimuli, which is surprising given ERK’s central role in directing key cellular behaviors.

The paper highlights methodological issues that may have confounded earlier estimates, including population averaging that masks cell-to-cell variability, challenges in performing repeated single-cell stimulations with diffusible ligands, limited numbers of well-resolved input states, and measurement noise. These limitations suggest that the true information capacity of the ERK pathway had not been conclusively established, motivating a precise determination.