Rnf4, a RING protein expressed in the developing nervous and reproductive systems, interacts with gscl, a gene within the DiGeorge critical region

A yeast a-hybrid screen was performed to identify possible transcriptional modulators interactive with goosecoid-like (gscl), a transcription factor w ith suppressive activity, expressed during early brain and gonad developmen t. The screen resulted in the identification of a RING protein known as rnf 4 or snrf, Gscl/rnf4 interactions were confirmed by affinity chromatography and by immunoprecipitation, Northern analysis confirmed earlier reports of ubiquitous rnf4 expression in adult tissues. Immunohistochemical analysis of mouse embryos revealed expression primarily in the developing nervous sy stem, with strong expression in the dorsal root ganglia and developing gona ds. In contrast to previous reports, both cytoplasmic and nuclear expressio n of rnf4 was documented. The results reported here confirm and extend earl ier reports of rnf4 expression. They suggest for the first time, that in ad dition to acting as a modulator of transcriptional activity, rnf4 may funct ion, as do other RING proteins, to promote the formation of intracytoplasmi c complexes involved in shuttling information between the cytoplasm and the nucleus. (C) 2000 Wiley-Liss, Inc.