FIGURE 4.

Effect of c-Fos, Fra-1, or c-Jun on lipin 1β PAP activity. a, schematic representation of Fra-1, c-Fos, and c-Jun aligning their bZip domain. b, BDs of the three proteins are aligned. Line represents identity, and colon represents conservative substitutions. Note the high homology between the BD of c-Fos and Fra-1 but not between that of c-Fos and c-Jun or Fra-1 and c-Jun. c, lipin 1β PAP I activity as a function of the molar concentration of the indicated recombinant oncoprotein was measured using Triton X-100/PA mixed micelles as in Fig. 2b. Results are the mean ± S.D. of a representative experiment performed in triplicate of at least three performed.