title: Expression and distribution of JNK/SAPK-associated scaffold protein JSAP1 in developing and adult mouse brain.
abstract: The c-Jun N-terminal kinase (JNK) is one of the three major mitogen-activated protein kinases (MAPKs) playing key roles in various cellular processes in response to both extracellular and intracellular stimuli. JNK/SAPK-associated protein 1 (JSAP1 also referred to as JIP3) is a JNK-associated scaffold that controls the specificity and efficiency of JNK signaling cascades. Here we studied its expression in mouse brains. JSAP1 mRNA was expressed in developing and adult brains, showing spatial patterns similar to JNK1-3 mRNAs. In embryos, JSAP1 immunolabeling was intense for progenitor cells in the ventricular zone throughout the brain and in the external granular layer of the cerebellum, and for neurons and glial cells differentiating in the mantle zone. In adults, JSAP1 was distributed in various neurons and Bergmann glia, with higher levels in striatal cholinergic interneurons, telencephalic parvalbumin-positive interneurons and cerebellar Purkinje cells. In these neurons, JSAP1 was observed as tiny particulate staining in spines, dendrites, perikarya and axons, where it was often associated with the smooth endoplasmic reticulum (sER) and cell membrane. Immunoblots revealed enriched distribution in the microsomal fraction and cytosolic fraction. Therefore, the characteristic cellular expression and subcellular distribution of JSAP1 might be beneficial for cells to efficiently link external stimuli to the JNK MAPK pathway and other intracellular machineries.
authors.affiliation: Department of Anatomy, Hokkaido University School of Medicine, Sapporo, Japan.
authors.forename: Eriko
authors.initials: E
authors.lastname: Miura
authors.forename: Masahiro
authors.initials: M
authors.lastname: Fukaya
authors.forename: Tokiharu
authors.initials: T
authors.lastname: Sato
authors.forename: Kazushi
authors.initials: K
authors.lastname: Sugihara
authors.forename: Masahide
authors.initials: M
authors.lastname: Asano
authors.forename: Katsuji
authors.initials: K
authors.lastname: Yoshioka
authors.forename: Masahiko
authors.initials: M
authors.lastname: Watanabe
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D001369:Axons / Q000378:metabolism / Q000648:ultrastructure; D001921:Brain / Q000166:cytology / Q000196:embryology* / Q000378:metabolism*; D002454:Cell Differentiation / Q000502:physiology; D002462:Cell Membrane / Q000378:metabolism / Q000648:ultrastructure; D002531:Cerebellum / Q000166:cytology / Q000196:embryology / Q000378:metabolism; D003600:Cytosol / Q000378:metabolism / Q000648:ultrastructure; D049229:Dendritic Spines / Q000378:metabolism / Q000648:ultrastructure; D018871:Endoplasmic Reticulum, Smooth / Q000378:metabolism / Q000648:ultrastructure; D005455:Fluorescent Antibody Technique; D018507:Gene Expression Regulation, Developmental / Q000502:physiology; D017403:In Situ Hybridization; D048031:JNK Mitogen-Activated Protein Kinases / Q000378:metabolism; D048670:MAP Kinase Kinase 4 / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D046529:Microscopy, Electron, Transmission; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism*; D009457:Neuroglia / Q000166:cytology / Q000378:metabolism*; D009474:Neurons / Q000166:cytology / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D013234:Stem Cells / Q000166:cytology / Q000378:metabolism*; D013687:Telencephalon / Q000166:cytology / Q000196:embryology / Q000378:metabolism
chemical_list: D048868:Adaptor Proteins, Signal Transducing; C403619:Mapk8ip3 protein, mouse; D009419:Nerve Tissue Proteins; D012333:RNA, Messenger; D048031:JNK Mitogen-Activated Protein Kinases; D048670:MAP Kinase Kinase 4