M dish

HTPCs were grown overnight in a culture dish (m-Dish, Ø 35 mm, high; Ibidi, Martinsried, Germany) under standard conditions. Then, cells were incubated in the presence or absence of epinephrine (1 mM) in DMEM without phenol red and without FCS in a humid atmosphere with 5% CO 2 at 37 C for 24 h. Optimal incubation conditions (5% CO 2 , 37 C, 95% relative humidity) were created by using an Ibidi heating system and an Ibidi gas incubation system. Time-lapse series were generated by taking a picture every 20 min for 24 h with a ProgRes MF camera (Jenoptik, Jena, Germany), the Micro-Manager 1.3 Microscopy Software (Ron Vale's Laboratory at UCSF, San Francisco, CA, USA) and a transmitted light microscope (Axiovert 135; Zeiss, Oberkochen, Germany).

For phase-contrast time-lapse imaging assays, cells were seeded in 12-well tissue culture plates and imaged in CO 2 -independent L15 medium without phenol red (Life Technologies) supplemented with 10% FCS, at 203 using an inverted video-microscope (Olympus IX83) equipped with an ORCA flash 4.0 camera and controlled by CellSens software.
For FRET imaging assays, HeLa cells were seeded on glass-bottom dishes (m-Dish, IBIDI), precoated with fibronectin (Sigma-Aldrich) at 1 mg/cm 2 and imaged in L15 without phenol red supplemented with 1% FCS. Imaging was performed using an inverted microscope (Leica DMI6000) controlled by Metamorph software and equipped with adaptive focus control, fast emission filter wheel (lambda 10-3, Sutter), electron multiplying charge coupled device (EMCCD) camera (Evolve 512; Photometrics), HCX PL APO 403/NA 1.30 oil immersion lens, and light-emitting diode (LED)-based illumination system (spectra X-light engine, Lumencor). Filters used were ET480/40m and ET535/30m and double band CFP/YFP dichroic mirror 51017bs from Chroma (Chroma Technology). Quantifications were performed using ImageJ software (Gavet and Pines, 2010a) . Intensity-modulated display (IMD) representations were performed using Metamorph software.