AMAP-1, a novel testis-specific AMY-1-binding protein, is differentially expressed during the course of spermatogenesis

AMY-1 has been identified by us as a c-Myc-binding protein and was found to stimulate c-Myc transcription activity. AMY-1 was also found to be associated with AKAP84/149 in the mitochondria in somatic cells and sperm, suggesting that it plays a role in spermatogenesis. To access the molecular function of AMY-1, a two-hybrid screening of cDNAs encoding AMY-1-binding proteins was carried out with AMY-1 as a bait using a human testis cDNA library, and a clone encoding a novel protein, AMAP-1, was obtained. The amap-1 gene was mapped at human chromosome 17q21. AMY-1 was found to bind to and be colocalized with AMAP-1 in human 293T and HeLa cells. AMAP-1 was found to be specifically expressed in the testis and expressed post-meiotically in the testis, as was AMY-1. These results suggest that both AMAP-1 and AMY-1 play roles in spermatogenesis.