HeLa cells were purchased from the Human Science Research Resources Bank (Sennanshi, Japan). The Cos7 cells used were Cos7/E3, a subclone of Cos7 cells established by Y. Fukui (National Research Institute of Health, Taiwan, Republic of China). HeLa cells and Cos7 cells were maintained in DMEM (Sigma-Aldrich, St. Louis, MO) supplemented with 10% FBS. The cells were plated on 35-mm glass base dishes or 96-well glass base plates (Asahi Techno Glass, Tokyo, Japan), which were coated with collagen type I (Nitta Gelatin, Osaka, Japan). Plasmids encoding FRET biosensors were transfected into HeLa cells and Cos7 cells by 293fectin or Lipofectamine 2000, according to the manufacturer's instructions (Invitrogen, San Diego, CA), respectively. EGF was purchased from Sigma-Aldrich. dbcAMP, TPA, Calyculin A, Anisomycin, PD153035, and JNK inhibitor VIII were purchased from Calbiochem (La Jolla, CA). PD184352 was obtained from Toronto Research Chemicals (Ontario, Canada). BI-D1870 was purchased from Symansis (Shanghai, China). Rapamycin was obtained from LC Laboratories (Woburn, MA). PLX-4720 was purchased from Selleck Chemicals (Houston, TX). The expression vector of piggyBac transposase was provided by A. Bradley (Wellcome Trust Sanger Institute, Cambridge, UK; Yusa et al., 2009 (link)). Phos-tag was obtained from the Phos-tag Consortium (Hiroshima, Japan; www.phos-tag.com). Anti-green fluorescence protein (GFP) sera were prepared in our laboratory. LI-COR (Lincoln, NE) blocking buffer and the IRDye680- and IRDye800-conjugated anti–rabbit and anti–mouse immunoglobulin G secondary antibodies were obtained from LI-COR.