Figure 6.

M1BP expression can prevent starvation-induced autophagy when expressed in vertebrate cells. (A) Representative immunofluorescent staining of unstarved and starved HeLa cells showing increased cytoplasmic staining of LC3A (green) and ZKSCAN3 upon starvation. Scale 25 µm. (B) Quantification of cytoplasmic immunofluorescence signal of LC3A and ZKSCAN3 in unstarved and starved HeLa cells confirming autophagy induction through the shuttling of ZKSCAN3 into the cytoplasm. (C) Representative immunofluorescence staining of LC3A (green) in independent experiments of starved HeLa cells demonstrates that cells containing transiently transfected M1BP (white) display generally lower levels of cytoplasmic LC3A accumulation. Nuclei are counterstained with DAPI (blue) and cell membranes marked with Phalloidin (red). Enlarged views of M1BP-transfected cells showing diminished cytoplasmic LC3A staining are shown below the main images. Scale 50 µm. (D) Quantification of cytoplasmic LC3A immunofluorescence signal in unstarved and starved HeLa cells demonstrates significant reduction of cytoplasmic LC3A in cells transiently transfected with M1BP. (E) RT-qPCR analyses of key vertebrate autophagy genes induced upon HeLa cell starvation demonstrate induction of expression is significantly inhibited in cells transiently transfected with M1BP.