The beta3A subunit gene (Ap3b1) of the AP-3 adaptor complex is altered in the mouse hypopigmentation mutant pearl, a model for Hermansky-Pudlak syndrome and night blindness.
Lysosomes, melanosomes and platelet-dense granules are abnormal in the mouse hypopigmentation mutant pearl. The beta3A subunit of the AP-3 adaptor complex, which likely regulates protein trafficking in the trans - Golgi network/endosomal compartments, was identified as a candidate for the pearl gene by a positional/candidate cloning approach. Mutations, including a large internal tandem duplication and a deletion, were identified in two respective pearl alleles and are predicted to abrogate function of the beta3A protein. Significantly lowered expression of altered beta3A transcripts occurred in kidney of both mutant alleles. The several distinct pearl phenotypes suggest novel functions for the AP-3 complex in mammals. These experiments also suggest mutations in AP-3 subunits as a basis for unique forms of human Hermansky-Pudlak syndrome and congenital night blindness, for which the pearl mouse is an appropriate animal model.
Pubmed ID: 9931340 RIS Download
Adaptor Protein Complex beta Subunits | Adaptor Proteins, Vesicular Transport | Albinism, Oculocutaneous | Alleles | Amino Acid Sequence | Animals | Base Sequence | COS Cells | Cloning, Molecular | Contig Mapping | DNA, Complementary | Female | Gene Expression | Genes | Hypopigmentation | Male | Membrane Proteins | Mice | Mice, Inbred C3H | Mice, Inbred C57BL | Mice, Mutant Strains | Molecular Sequence Data | Monomeric Clathrin Assembly Proteins | Mutation | Nerve Tissue Proteins | Night Blindness | Phosphoproteins | RNA, Messenger | Sequence Alignment | Sequence Homology, Amino Acid | Sequence Homology, Nucleic Acid | Tissue Distribution | Transcription, Genetic