Mitogen Activated Protein Binding Protein Interacting Protein (MAPBPIP)

MAPBPIP is highly conserved with a mouse protein associated with the cytoplasmic face of late endosomes and lysosomes. The mouse protein interacts with MAPK scaffold protein 1, a component of the mitogen-activated protein kinase pathway. In humans, a mutation in this gene has been associated with a primary immunodeficiency syndrome, and suggests a role for this protein in endosomal biogenesis. The 125-amino acid mouse protein has a predicted molecular mass of 13.5 kD. By database analysis, they identified highly conserved homologs in human, rat, cow, chicken, and Drosophila. Proteinase K digestion and a variety of immunofluorescence assays suggested a peripheral association of p14 with the cytoplasmic face of late endosomes/lysosomes in a variety of cell types.