The maize WD-repeat gene ZmRbAp1 encodes a member of the MSI/RbAp sub-family and is differentially expressed during endosperm development

Members of the MSI/RbAp sub-family of WD-repeat proteins are widespread in eukaryotic organisms and form part of multiprotein complexes that are invol ved in various biological pathways, including chromatin assembly, regulatio n of gene transcription, and cell division. In this study we report the iso lation and characterization of a cDNA sequence from Zea mays, which encodes an RbAp-like protein (ZmRbAp1) that binds acetylated histories H3 and H4 a nd suppresses mutations that have a negative effect on the Ras/cAMP pathway in yeast. The ZmRbAp genes form a gene family and are expressed in differe nt tissues of Z. mays L. plants. Determination of its expression pattern du ring maize seed development revealed that ZmRbAp transcripts are abundant d uring the initial stages of endosperm formation. In addition, the transcrip ts are specifically localized in shoot apical meristem and leaf primordia o f the embryo. A possible role for the ZmRbAp genes in early endosperm diffe rentiation and plant development is discussed.