FIGURE 2.

Quantitation of hnRNP L and LL protein levels. (A,B) Cytoplasmic (lanes S100) and nuclear (lanes NE) extracts were prepared from HeLa cells (Lee et al. 1988), and 12.5 μg of total protein from each extract was subjected to Western blot analysis, with γ-tubulin Western signals serving as an internal standard. Signals were quantitated by comparing with Western signals obtained with recombinant His-tagged hnRNP L/LL proteins (5, 10, 30, 50, or 100 ng of either protein, as indicated above the lanes). (A) hnRNP L was detected by monoclonal antibody 4D11, (B) hnRNP LL by our own antibody (see Materials and Methods). To visualize the less abundant hnRNP LL in B, two different exposures are shown (overexposure at the bottom). The electrophoretic positions of His-tagged hnRNP L, -LL, and of γ-tubulin are marked on the sides.