Nuclear Protein In Testis (NUT)

By analyzing the region of chromosome 15 involved in a t(15;19) translocation, followed by EST database analysis and RT-PCR, French et al. (2003) cloned NUT. The deduced 1,127-amino acid protein has a calculated molecular mass of about 120 kD. Northern blot analysis of several normal human tissues detected a 3.6-kb transcript only in testis. The oncogenic fusion protein contains the N-terminal sequence of BRD4, including 2 bromodomains, 2 nuclear localization signals (NLS), an ET domain, and a serine-rich region, followed by almost the entire NUT sequence, including a C-terminal NLS. The fusion protein lacks only the first 5 NUT residues. Northern blot analysis detected a 6.4-kb fusion transcript in a t(15;19)-positive carcinoma cell line. No NUT/BRD4 transcripts were detected.