The F-Box Protein Skp2 Participates in c-Myc Proteosomal Degradation and Acts as a Cofactor for c-Myc-Regulated Transcription

• Autores: Natalie Von Der Lehr, Siqin Wu, Sara Johansson
• Localización: Molecular cell, ISSN 1097-2765, Vol. 11, Nº 5, 2003, pág. 1189
• Idioma: inglés
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• Resumen

  • The transcription regulatory oncoprotein c-Myc controls genes involved in cell growth, apoptosis, and oncogenesis. c-Myc is turned over very quickly through the ubiquitin/proteasome pathway. The proteins involved in this process are still unknown. We have found that Skp2 interacts with c-Myc and participates in its ubiquitylation and degradation. The interaction between Skp2 and c-Myc occurs during the G1 to S phase transition of the cell cycle in normal lymphocytes. Surprisingly, Skp2 enhances c-Myc-induced S phase transition and activates c-Myc target genes in a Myc-dependent manner. Further, Myc-induced transcription was shown to be Skp2 dependent, suggesting interdependence between c-Myc and Skp2 in activation of transcription. Moreover, Myc-dependent association of Skp2, ubiquitylated proteins, and subunits of the proteasome to a c-Myc target promoter was demonstrated in vivo. The results suggest that Skp2 is a transcriptional cofactor for c-Myc and indicates a close relationship between transcription activation and transcription factor ubiquitination.