Translin (TSN), also known as testis-brain RNA-binding protein, is proposed to bind to breakpoint junctions at chromosomal translocations in the nucleus and to specific RNAs in the cytoplasm. In germ cells of the mouse testis, it recognizes target mRNAs transcribed by the transcription factor CREM-tau in spermatids, specific meiotically expressed mRNAs, and a noncoding RNA that encodes piRNAs. Here we show that TSN also binds to the microRNA miR-122a. MiR-122a is expressed in late-stage germ cells and is complementary to a sequence in the 3' untranslated region of the transition protein 2 mRNA. The binding of TSN to miR-122a increases its in vivo stability, suggesting an additional posttranscriptional function for TSN.
