Expression and distribution of JNK/SAPK‐associated scaffold protein JSAP1 in developing and adult mouse brain

• Published in: Journal of neurochemistry Vol. 97; no. 5; pp. 1431 - 1446
• Main Authors: Miura, Eriko, Fukaya, Masahiro, Sato, Tokiharu, Sugihara, Kazushi, Asano, Masahide, Yoshioka, Katsuji, Watanabe, Masahiko
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01-06-2006; Blackwell
• Subjects: Adaptor Proteins, Signal Transducing - genetics; Adaptor Proteins, Signal Transducing - metabolism; Animals; Axons - metabolism; Axons - ultrastructure; Biochemistry and metabolism; Biological and medical sciences; brain; Brain - cytology; Brain - embryology; Brain - metabolism; Cell Differentiation - physiology; Cell Membrane - metabolism; Cell Membrane - ultrastructure; Central nervous system; Cerebellum - cytology; Cerebellum - embryology; Cerebellum - metabolism; Cerebral circulation. Blood-brain barrier. Choroid plexus. Cerebrospinal fluid. Circumventricular organ. Meninges; Chemistry; Cytosol - metabolism; Cytosol - ultrastructure; Dendritic Spines - metabolism; Dendritic Spines - ultrastructure; Endoplasmic Reticulum, Smooth - metabolism; Endoplasmic Reticulum, Smooth - ultrastructure; Fluorescent Antibody Technique; Fundamental and applied biological sciences. Psychology; Gene expression; Gene Expression Regulation, Developmental - physiology; immunoblot; immunohistochemistry; In Situ Hybridization; JIP3; JNK Mitogen-Activated Protein Kinases - metabolism; JSAP1; MAP Kinase Kinase 4 - metabolism; Mice; Mice, Inbred C57BL; Mice, Knockout; Microscopy, Electron, Transmission; Nerve Tissue Proteins - genetics; Nerve Tissue Proteins - metabolism; Neuroglia - cytology; Neuroglia - metabolism; Neurons; Neurons - cytology; Neurons - metabolism; Neurosciences; Proteins; Ribonucleic acid; RNA; RNA, Messenger - metabolism; Rodents; Signal transduction; Stem Cells - cytology; Stem Cells - metabolism; Telencephalon - cytology; Telencephalon - embryology; Telencephalon - metabolism; Vertebrates: nervous system and sense organs; Cerebellum; JIP3; JSAP1; Embryo; Calcium; Neuroglia; Central nervous system; terminal kinase; Encephalon; Interneuron; Osteoarticular system; Binding protein; Signal transduction; Specificity; Efficiency; immunohistochemistry; Enzyme; Stress-activated kinase; Rodentia; immunoblot; Mitogen-activated protein kinase; Basal ganglion; brain; Extracellular; Vertebrata; Mammalia; Mouse; c-Jun NH; Intracellular; Progenitor cell; in situ hybridization
• ISSN: 0022-3042; 1471-4159
• DOI: 10.1111/j.1471-4159.2006.03835.x

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.