Pim-1 translocates sorting nexin 6/TRAF4-associated factor 2 from cytoplasm to nucleus

Pim-1, an oncogene product of serine/threonine kinase, has been found to pl ay roles in apoptosis induction/suppression, cell-cycle progression and tra nscriptional regulation by phosphorylating the target proteins involved in these processes. The target proteins phosphorylated by Pim-1, including p10 0, Cdc25A, PAP-1 and heterochromatin protein 1, have been identified. The p recise functions of Pim-1, however, are still poorly understood. In this st udy, we identified tumor necrosis factor receptor-associated factor 4-assoc iated factor 2/sorting nexin 6 (TFAF2/SNX6) as a Pim-1-binding protein, and we found that TFAF2/SNX6 was phosphorylated and translocated from the cyto plasm to nucleus by Pim-1. This translocation of the protein was not affect ed by Pim-l-dependent phosphorylation. Since sorting nexins, including TFAF 2/SNX6, have been reported to be located in the cytoplasm or membrane by as sociation with several receptors of tyrosine- or serine/threonine-kinase, t his is the first report of TFAF2/STNX6 being located in the nucleus after b inding to Pim-1. (C) 2001 Federation of European Biochemical Societies. Pub lished by Elsevier Science B.V. All rights reserved.