Regulation of RNA polymerase I transcription in response to F9 embryonal carcinoma stem cell differentiation

Abstract

Dramatic changes in the patterns of transcription are a common feature of early development. We have used F9 embryonal carcinoma cells as a model system to study gene regulation during an early stage of murine embryogenesis. We find that transcription by RNA polymerase I decreases when F9 cells differentiate into parietal endoderm. The reduced rate of transcription is associated with a down-regulation of several components of the class I transcription apparatus. The most substantial change involves the essential factor SL1, which is a multisubunit complex that contains the TATA- binding protein and three TATA-binding protein-associated factors (TAFs). The abundance of two of these TAFs, TAF(I)45 and TAF(I)95, decreases during F9 cell differentiation. Developmental regulation of a specific class of genes may therefore be achieved through changes in the availability of TAFs.