a, Western blot analysis of yeast cell lysates with polyclonal anti-flag antibody to detect flag-tagged human Beclin 1 expression. Two-hundred micrograms of protein per lane was loaded. SEY6210, wild-type yeast; JCY3000, SEY6210 disrupted in apg6/vps30; (+) control, lysates of mammalian cells transfected with flag-beclin 1.b, Autophagicbody formation in yeast deprived of nitrogen in the presence (+) and absence (-) of 1 mM PMSF. Arrows denote cells that would be scored as positive in the experiment shown in c.c, Quantitative effects of apg6/vps30 and beclin 1 transformation on autophagicbody formation in apg6/vps30-disrupted yeast in the presence of PMSF. Cells with one or more autophagic bodies within the vacuole were scored as positive (see arrows in b). A minimum of 100 cells was counted for each sample. Results represent the mean (±s.e.m.) percentage of cells with autophagic bodies within the vacuole for triplicate samples. Similar results were obtained in five independent experiments.d, Sorting of vacuolar protein carboxypeptidase Y, (CPY). p2CPY, precursor form; mCPY, sorted mature form. Mr, relative molecular mass.

a-f, Electron micrographs of MCF7.control (clone 38) (a, b) and MCF7.beclin1 (clone 17) cells (c- f) grown in nutrient-rich media (a, c) or subjected to 4 h of serum and amino-acid deprivation (b, d-f). Asterisks in e and f denote autophagic vacuoles that would be counted in the experiment shown in g. Autophagic vacuoles were defined as double-membrane vacuolar structures containing recognizable cytoplasmic contents. Scale bars, 1 µm.

g, Quantitative effects of beclin 1 on basal and nutrient-deprivation-induced autophagy of MCF7 cells. Bars indicate mean (±s.e.m.) number of autophagic vacuoles per cell for cells growing in normal media (black), for cells subjected to 4 h of serum and amino-acid deprivation (grey), and for cells pre-treated for 30 min with 10 mM 3-MA and subjected to 4 h of serum and amino-acid deprivation in the presence of 3-MA (open). Mean was determined by counting the total number of autophagic vacuoles in each cell for 100 cells per clone per treatment.h, Comparison of the rates of degradation of long-lived proteins in MCF7.control cells (squares, clone 38), MCF7.beclin1 cells (circles, clone 17) and MCF7.beclin1stop cells (triangles, clone 70), in EBSS + 10% serum and complete amino acids (open symbols, solid lines) in EBSS alone (closed symbols, solid lines), and in EBSS + 10 mM 3-MA (closed symbols, dotted lines). Results are mean (±s.e.m.) of triplicate wells. Similar results were obtained in three independent experiments. Results shown with these clones are representative of results obtained with other clones analysed by electron microscopy in g.a, Western blot analysis of flag-tagged beclin-1-transfected MCF7 clones. C, MCF7.control cells (clone 38); St, MCF7.beclin1stop cells (clone 70). Mr, relative molecular mass.b, Western blot analysis of flag-tagged beclin1stop-transfected MCF7 clones. C, MCF.control cells (clone 38); B, MCF7.beclin1 cells (clone 1).c, Photomicrographs of MCF7.control cells (left panel, clone 38), MCF7. beclin1 cells (middle panel, clone 17) and MCF7.beclin1stop cells (right panel, clone 70) 48 h after seeding at similar densities.d, Proliferation of MCF7.control cells (clones 37 and 38; closed squares and circles, respectively, solid lines), MCF7.beclin1 cells (clones 1, 6, 17; open squares, circles, triangles, respectively, solid lines) and MCF7.beclin1stop cells (clone 70, closed triangles, dotted line). Results represent mean Absorbance (A) (±s.e.m.) for six wells; similar results were obtained in three independent experiments.e, Cell viability of MCF7 clones determined by trypan blue staining. Symbols for each clone are as in df, Clonigenicity in semisolid medium (soft agar) of MCF7 clones. Results are mean (±s.e.m.) for pooled triplicate wells from 3-4 independent experiments.g, Tumour formation in NCR nude mice injected subcutaneously with MCF7 clones. Numbers on top of bar indicate number of autopsy-confirmed tumours at 8 weeks per number of mice injected with each clone.a, Western blot analysis of human breast carcinoma cell lines. Results are from 8 representative cell lines out of a total of 11 analysed.b, Western blot analysis of matched normal breast and breast carcinoma tissue from patients with sporadic invasive breast carcinoma. Results are from 7 representative cases out of a total of 17 analysed. N, normal breast tissue; T, tumour tissue; Mr, relative molecular mass.c, Immunohistochemical analysis of paraffin-embedded sections of breast tissue from patient 441 shown in b. Adjacent sections are stained with pre-immune 843 rabbit serum (left column), 843 anti-Beclin 1serum (middle column) and anti-cytokeratin (right column). Top row shows low power view of region of breast containing tumour (T) and normal mammary epithelial duct (N). Middle row shows higher power view of normal mammary epithelial duct. Bottom row shows higher power view of tumour. Scale bars, 1 mm.