Encodes almost entirely the C-terminal domain of poly(A)-binding proteins (PABPs). Plays a role in normal seed development and growth. Interacts with ERD15/CID1, CID7, CID8 and CID12. Mainly expressed in flower buds and in siliques containing developing seeds. Expressed in the central cell before fertilization and in the endosperm of seeds from the time of fertilization. In vegetative tissues, expression is repressed by MET1. In the endosperm, the maternal MPC allele is activated by DME and the paternal MPC allele is repressed by MET1. The MPC locus is imprinted. Only the maternal inherited allele is expressed in endosperm.