Two TFIIIA activities regulate expression of the Xenopus 5S RNA gene families.

• DOI: 10.1101/gad.3.10.1602
• Publication Date: 2007-06-05T21:15:46Z
• Authors: J Blanco; L Millstein; M A Razik; S Dilworth; C Cote; J Gottesfeld
• Keywords: Transcription

Immunoblotting experiments with polyclonal and monoclonal anti-transcription factor IIIA (TFIIIA) antibodies reveal different electrophoretic forms of TFIIIA in extracts from immature mature oocytes Xenopus laevis. The well-characterized 39-kD species is present approximately 10(12) copies per cell stage I-III previtellogenic declines abundance by 10- to 20-fold during oogenesis. An immunologically related protein apparent molecular mass 42 kD at 2-4% the level oocytes, this increases dramatically Both 39- 42-kD proteins are complexed 5S RNA 7S ribonucleoprotein (RNP) particles. High-level transcription oocyte-type genes vitro requires oocyte TFIIIA, whereas both support somatic-type transcription. does not a fractionated system derived oocytes. proteins, however, bind comparable affinities exhibit similar DNase footprints on genes. These results suggest model for developmental regulation gene where serves as an activator repressor early embryogenesis.