Identification of MVH target mRNA

During mammalian spermatogenesis the mouse VASA homolog (MVH), a germ cell-specific DEAD-box type RNA binding protein, localizes in a germline-specific RNA granule termed the chromatoid body (CB). Genetic analyses have revealed that MVH is essential to progress through spermatogenesis, although the molecular mechanisms of its function remain elusive. We found that the acetyltransferase HAT1 and its cofactor, p46, are specifically co-localized with MVH in the CB and acetylate MVH at Lys-405, leading to inactivation of its RNA binding activity. Notably, the acetylation is developmentally regulated, paralleling the temporally regulated co-localization of HAT1 and p46 in the CB. We have identified 858 mRNAs as MVH targets, a large proportion of which correspond to previously identified translationally arrested genes. Importantly, eIF4B mRNA, a target of MVH, is selectively released from MVH-RNP when MVH is acetylated, paralleling an increase in eIF4B protein. These findings reveal a novel signaling pathway that links acetylation to RNA processing in the control of spermatogenesis. IMVH target mRNA was purified from MVH immuno precipitated complex, followed by RNA purification and identified by DNA chip. In this study, we identified more than 800 MVH target mRNA in testis.