CHARACTERIZATION OF AN ELEMENT POSITIVELY REGULATING THE TRANSCRIPTION OF MSSP GENE-2 WHICH ENCODES C-MYC BINDING-PROTEINS

MSSP gene-2 encodes at least three alternative splicing products, MSSP -1, MSSP-2, and Scd, which have been implied to function as factors re gulating DNA replication, transcription, apoptosis induction, and cell -cycle movement, via the interaction with C-MYC. We have previously sh own that the Mup1 sequence from -474 to -440 in the region required fo r transactivation of the MSSP gene-2 was protected from DNaseI digesti on in vitro. Here, we report that the Mup1 sequence carries a positive transcriptional activity, and that the activity was lost by point mut ations that inhibited the formation of specific nucleoprotein complexe s on the sequence. In Southwestern analyses, two proteins of 38 and 62 kDa directly interacted with the Mup1 sequence. (C) 1998 Elsevier Sci ence B.V. All rights reserved.