In this study , we evaluated human TRIB2 - interacting proteins and investigated if the Trbl - mediated degradation of String is likely to be functionally conserved in vertebrate TRIB2 pseudokinase , which have been linked to a variety of cancer - associated signaling pathways [ 34 ] . Here , we show that mammalian CDC25B and CDC25C are novel interacting partners of TRIB2 . Consistently , the overexpression of TRIB2 promotes polyubiquitination and proteasome - dependent degradation of CDC25C. Our data suggests TRIB2 - mediated degradation of CDC25C takes place in the nucleus . In accordance with a potential functional role of TRIB2 in cell cycle regulation , we also find that TRIB2 protein expression is tightly regulated during the cell cycle .