Figure 1.

CHIP regulates cell surface ErbB2 levels. (A) Western blot analysis of SKBR3 and 21MT1 cell lysate for CHIP, ErbB2, phospho-Akt and total Akt levels; β-actin was used as a loading control. (B) SKBR3 and 21MT1 cell surface ErbB2 level was determined by FACS analysis. Representative FACS profiles are shown in top panel. Quantification of surface ErbB2 levels (based on relative change in mean fluorescence intensity with control shRNA as 1) is shown in the bottom panel. Data represent mean ± SEM, n = 3. * p < 0.05. (C) SKBR3 control shRNA, CHIP shRNA, MSCV-puro and MSCV-CHIP cells were seeded on glass coverslips, fixed, and stained with anti-ErbB2 antibody followed by staining with the corresponding fluorescent secondary conjugates. Coverslips were mounted with anti-fade containing DAPI and images were acquired under a Zeiss LSM 710 confocal microscope.