Fig. 3. Distribution of radiolabeled FN in different fractions is comparable between FAK^-/- and DA2 cells. Proteins were labeled with a pulse of 1.0 mCi/ml L-[³⁵S]methionine and L-[³⁵S]cysteine mixture for 15 minutes. Distribution of ³⁵S-labeled FN was followed after 2 and 15 hours in three different fractions (DOC-soluble, DOC-insoluble SDS-soluble, and secreted into medium) and compared with a total amount of the labeled FN (time 0). Data (means from three repeats) suggest that there is only slightly more FN incorporated into the DOC-insoluble SDS-soluble fraction in DA2 cells. However, the FAK^-/- cells secreted somewhat more FN into the medium.