title: Expression, synaptic localization, and developmental regulation of Ack1/Pyk1, a cytoplasmic tyrosine kinase highly expressed in the developing and adult brain.
abstract: Cytosolic tyrosine kinases play a critical role both in neural development and in adult brain function and plasticity. Here we isolated a cDNA with high homology to human Ack1 and mouse Tnk2. This cDNA directs the expression of a 125-kD protein that can be autophosphorylated in tyrosines. Initially, this clone was named Pyk1 for proline-rich tyrosine kinase (Lev et al., 1995); however, since it corresponds to the mouse homolog of Ack1, here we called it Ack1/Pyk1. In this study we show that Ack1/Pyk1 mRNA and protein is highly expressed in the developing and adult brain. The highest levels of Ack1/Pyk1 expression were detected in the hippocampus, neocortex, and cerebellum. Electron microscopy studies showed that Ack1/Pyk1 protein is expressed in these regions both at dendritic spines and presynaptic axon terminals, indicating a role in synaptic function. Furthermore, we demonstrate that Ack1/Pyk1 mRNA levels are strongly upregulated by increased neural activity, produced by intraperitoneal kainate injections. During development, Ack1/Pyk1 was also expressed in the proliferative ventricular zones and in postmitotic maturing neurons. In neuronal cultures, Ack1/Pyk1 was detected in developing dendrites and axons, including dendritic tips and growth cones. Moreover, Ack1/Pyk1 colocalized with Cdc42 GTPase in neuronal cultures and coimmunoprecipitated with Cdc42 in HEK 293T cells. Altogether, our findings indicate that Ack1/Pyk1 tyrosine kinase may be involved both in adult synaptic function and plasticity and in brain development.
authors.affiliation: Developmental Neurobiology and Regeneration Lab, Institute of Biomedical Research of Barcelona-Parc Científic de Barcelona, University of Barcelona, Josep Samitier 1-5, E08028 Barcelona, Spain. jurena@pcb.ub.es
authors.forename: Jesús Mariano
authors.initials: JM
authors.lastname: Ureña
authors.forename: Anna
authors.initials: A
authors.lastname: La Torre
authors.forename: Albert
authors.initials: A
authors.lastname: Martínez
authors.forename: Eve
authors.initials: E
authors.lastname: Lowenstein
authors.forename: Neus
authors.initials: N
authors.lastname: Franco
authors.forename: Raphaelle
authors.initials: R
authors.lastname: Winsky-Sommerer
authors.forename: Xavier
authors.initials: X
authors.lastname: Fontana
authors.forename: Ricardo
authors.initials: R
authors.lastname: Casaroli-Marano
authors.forename: Miguel Angel
authors.initials: MA
authors.lastname: Ibáñez-Sabio
authors.forename: Marta
authors.initials: M
authors.lastname: Pascual
authors.forename: José Antonio
authors.initials: JA
authors.lastname: Del Rio
authors.forename: Luis
authors.initials: L
authors.lastname: de Lecea
authors.forename: Eduardo
authors.initials: E
authors.lastname: Soriano
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D015152:Blotting, Northern / Q000379:methods; D015153:Blotting, Western / Q000379:methods; D001921:Brain / Q000166:cytology / Q000196:embryology / Q000254:growth & development / Q000378:metabolism*; D002478:Cells, Cultured; D003001:Cloning, Molecular / Q000379:methods; D004622:Embryo, Mammalian; D018690:Excitatory Amino Acid Agonists / Q000494:pharmacology; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects / Q000502:physiology*; D005904:Glial Fibrillary Acidic Protein / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods; D047468:Immunoprecipitation / Q000379:methods; D017403:In Situ Hybridization / Q000379:methods; D007608:Kainic Acid / Q000494:pharmacology; D051379:Mice; D016253:Microscopy, Immunoelectron / Q000379:methods; D008869:Microtubule-Associated Proteins / Q000378:metabolism; D009474:Neurons / Q000187:drug effects / Q000378:metabolism / Q000648:ultrastructure; D019606:Phosphoamino Acids / Q000378:metabolism; D010766:Phosphorylation; D017729:Presynaptic Terminals / Q000378:metabolism / Q000648:ultrastructure; D011505:Protein-Tyrosine Kinases / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000096:biosynthesis; D013569:Synapses / Q000378:metabolism* / Q000648:ultrastructure; D013997:Time Factors; D014404:Tubulin / Q000378:metabolism; D020764:cdc42 GTP-Binding Protein / Q000378:metabolism
chemical_list: D018690:Excitatory Amino Acid Agonists; D005904:Glial Fibrillary Acidic Protein; D008869:Microtubule-Associated Proteins; C079240:Mtap2 protein, mouse; D019606:Phosphoamino Acids; D012333:RNA, Messenger; D014404:Tubulin; C462941:beta3 tubulin, mouse; C498594:Tnk2 protein, mouse; D011505:Protein-Tyrosine Kinases; C403262:TNK2 protein, human; D020764:cdc42 GTP-Binding Protein; D007608:Kainic Acid