Figure 1.
p27BBP/eIF6 is present in all cell lines, and in a cytoskeletal associated pool. (Left) 30 μg of total protein extracts from established cell lines and primary cultures were run on 12% acrylamide gels, transferred on immobilon-P membranes and blotted with the p27BBP/eIF6 antiserum, followed by ECL detection. The arrow points at the p27BBP/eIF6 band. The cell lines were mouse NIH/3T3 fibroblasts, human A431 epidermoid carcinoma, human HeLa epitheloid carcinoma, human pancreatic carcinoma FG2, human Jurkat T cells, transformed human keratinocytes HaCaT, human insulinoma cells Rin2A, and human neuroblastoma SK-N-MC. Primary cultures were mouse resting splenocytes and human fibroblasts. (Right) p27BBP/eIF6 in Xenopus oocytes extracted either in Laemmli buffer (total), or according to the nuclear matrix/intermediate filaments procedure of He et al. (1990, see Materials and Methods). The lane marked soluble contains cytosolic proteins extracted with an isotonic Triton X-100 buffer. The lane marked insoluble contains nuclear matrix/intermediate filament-associated proteins left after sequential extraction with ammonium sulphate, nuclease, and high salt.