Missense mutations in PIM-1 and c-MYC. (A) Schematic representation of the Pim-1 protein: hatched regions contain catalytic domains highly conserved in most protein kinases. The 2 putative phosphorylation sites (P) are also indicated. The Pim-1 protein sequence, residues 1-174, is expanded in the lower panel to show the distribution of the amino acid changes introduced by mutations in 3 AIDS-NHL cases. (B) Diagram of the c-Myc protein, with its relevant functional domains and the 2 N-terminal residues (Thr58 and Ser62) involved in the response to p107-mediated suppression of activity and in the control of protein stability by phosphorylation-dependent ubiquitination.^41-43  The region analyzed is aligned with the sequences of 4 mutated AIDS-NHL cases. NL indicates nuclear localization signal; bHLHLZ, basic Helix Loop Helix Leucine Zipper domain.