title: Developmentally regulated mRNA splicing of clathrin assembly protein 3 (AP-3).
abstract: Clathrin assembly protein 3 (AP-3) is a neuron-specific component of clathrin coated vesicles. Because it promotes the assembly of uniform clathrin cages, AP-3 may play a regulatory role in synaptic vesicle recycling. Previously, using the monoclonal antibody MabR-18, we demonstrated that AP-3 expression starts from the embryonic stage and is maintained at high levels from the early postnatal stages through adult. In order to study the expression of AP-3 during early postnatal development at the mRNA level, RT-PCR analysis was performed. We divided the coding region of AP-3 into 10 regions and designed primers to amplify each region. As a result, developmentally regulated splicing sites were found in two regions. In one region, a PCR product with a 108-bp deletion was detected from postnatal day 10 (P10). In the other region, a product with a 15-bp deletion was increased compensating for the decrease of the undeleted product. The expression of isoforms changed mainly from around P7 to P10, whereas the level of AP-3 protein remained relatively constant throughout postnatal development. These results suggest that the expression of AP-3 isoforms with mRNA splicing is developmentally regulated in the brain and may be involved in the maturation of synaptic vesicle recycling.
authors.affiliation: Advanced Research Laboratory, Research and Development Center, Toshiba Corporation, Kawasaki, Japan. 000092050374@tg-mail.toshiba.co.jp
authors.forename: M
authors.initials: M
authors.lastname: Ishihara-Sugano
authors.forename: H
authors.initials: H
authors.lastname: Nakae
mesh_terms: D033942:Adaptor Proteins, Vesicular Transport; D000375:Aging; D000595:Amino Acid Sequence; D000818:Animals; D000911:Antibodies, Monoclonal; D001483:Base Sequence; D001921:Brain / Q000196:embryology / Q000254:growth & development / Q000378:metabolism*; D002966:Clathrin / Q000378:metabolism; D017931:DNA Primers; D005314:Embryonic and Fetal Development; D018507:Gene Expression Regulation, Developmental; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D034041:Monomeric Clathrin Assembly Proteins; D009419:Nerve Tissue Proteins / Q000096:biosynthesis* / Q000737:chemistry; D010750:Phosphoproteins / Q000096:biosynthesis* / Q000737:chemistry; D016133:Polymerase Chain Reaction; D012326:RNA Splicing; D012333:RNA, Messenger / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D033942:Adaptor Proteins, Vesicular Transport; D000911:Antibodies, Monoclonal; D002966:Clathrin; D017931:DNA Primers; D034041:Monomeric Clathrin Assembly Proteins; D009419:Nerve Tissue Proteins; D010750:Phosphoproteins; D012333:RNA, Messenger; C439023:clathrin assembly protein AP180