63 n a 1.4 oil objective

The cells were washed twice in PBS and fixed for 10 min with 4% paraformaldehyde in PBS. After three washes in PBS, the fixed cells were permeabilized with 0.2% Triton X-100 and 1% bovine serum albumin solution was used for blocking. The cells were incubated with PRMT1 antibody (dilution ratio 1:100) for 15 h at 4 °C. After three washes in PBS, the cells were incubated with anti-rabbit fluorescein isothiocyanate (FITC) secondary antibody (Sigma, MO, USA). Then, the cells were mounted on slides and the nuclei were visualized with DAPI. Immunofluorescence imaging was performed on a Leica TCS SP5 AOBS laser scanning confocal microscope (Leica Microsystems, Heidelberg, Germany) using a Leica 63 × (N.A. 1.4) oil objective located at the Gwangju Center of the Korea Basic Science Institute. Excitation (496 and 405 nm) and emission (500–535, 449–461 nm) were observed for the FITC-conjugated construct and DAPI, respectively. For all experiments, the exposure time was kept the same for all samples.

Double-immunofluorescence was performed as previously described [23 (link)], using anti-AP-1 (ab21981; 1:200; Abcam) and anti-TXNIP (NBP1-54578; 1:200; Novus Biologicals) antibodies, and imaging was completed using a Leica TCS SP5 AOBS laser scanning confocal microscope (Leica Microsystems, Hesse, Germany) under a Leica 63× (N.A. 1.4) oil objective.