Human p29 has been demonstrated in the yeast two-hybrid method and in vitro GST pull-down assay to associate with GCIP, a cyclin D interacting protein. In this study, we describe the cloning and genomic structure of the mouse homologue, mp29. The overall mouse mp29 amino acid sequence is highly identical (91%) to human p29. Polyclonal antibody against mp29 was raised and the subcellular localization of mp29 was identified to be in the nucleus. Genomic clones containing mp29 gene were isolated and this gene was divided into seven exons spanning 9kb of genomic DNA. The transcription initiation site of mp29 gene was determined to be 94bp upstream of the translation initiation codon and the first 140bp proximal TATA-less promoter region is required to activate minimal transcription of mouse mp29 gene in mammalian cells.