Nucleolar retention of a translational C/EBPalpha isoform stimulates rDNA transcription and cell size.

ABSTRACT: The messenger RNA of the intronless CEBPA gene is translated into distinct protein isoforms through the usage of consecutive translation initiation sites. These translational isoforms have distinct functions in the regulation of differentiation and proliferation due to the presence of different N-terminal sequences. Here, we describe the function of an N-terminally extended protein isoform of CCAAT enhancer-binding protein alpha (C/EBPalpha) that is translated from an alternative non-AUG initiation codon. We show that a basic amino-acid motif within its N-terminus is required for nucleolar retention and for interaction with nucleophosmin (NPM). In the nucleoli, extended-C/EBPalpha occupies the ribosomal DNA (rDNA) promoter and associates with the Pol I-specific factors upstream-binding fac

SUBMITTER: Muller C 

PROVIDER: S-EPMC2810377 | biostudies-literature | 2010 Mar

REPOSITORIES: biostudies-literature