Temporal inhibition of ERK Activity by Optogenetic Control of MAPK Phosphatase 3

Abstract

The functional outcome of the Ras/ERK pathway is encoded by both signal amplitude and temporal kinetics. While a suite of optogenetic strategies allow for precise activation of the Ras/ERK pathway, inhibition of this pathway remains challenging because most negative regulators do not function through subcellular protein translocation or dimerization, features often utilized in common optogenetic strategies. Here, we developed an optogenetic split protein system to accomplish reversible inhibition of ERK activity using the MAPK phosphatase 3 (opto‐sMKP3). Opto‐sMKP3 reversibly inhibits ERK activity under patterned blue light stimulation. Scanning of a 6‐hour pERK inhibition window revealed that equal reduction of PC12 cell differentiation occurs regardless of the placement of the window, indicating that persistent pERK activity is necessary for maximum PC12 cell differentiation. In combination with current optogenetic strategies, opto‐sMKP3 provides an emerging modality to achieve bi‐directional control of the Ras/ERK pathway and helps identify how signaling dynamics encodes functional outcome.Support or Funding InformationSRS thanks the support of the Westcott Bioscience Fellowship from the Department of Biochemistry at UIUC. KZ thanks the support from the School of Molecular and Cellular Biology at UIUC.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.