title: MST3 kinase phosphorylates TAO1/2 to enable Myosin Va function in promoting spine synapse development.
abstract: Mammalian Sterile 20 (Ste20)-like kinase 3 (MST3) is a ubiquitously expressed kinase capable of enhancing axon outgrowth. Whether and how MST3 kinase signaling might regulate development of dendritic filopodia and spine synapses is unknown. Through shRNA-mediated depletion of MST3 and kinase-dead MST3 expression in developing hippocampal cultures, we found that MST3 is necessary for proper filopodia, dendritic spine, and excitatory synapse development. Knockdown of MST3 in layer 2/3 pyramidal neurons via in utero electroporation also reduced spine density in vivo. Using chemical genetics, we discovered thirteen candidate MST3 substrates and identified the phosphorylation sites. Among the identified MST3 substrates, TAO kinases regulate dendritic filopodia and spine development, similar to MST3. Furthermore, using stable isotope labeling by amino acids in culture (SILAC), we show that phosphorylated TAO1/2 associates with Myosin Va and is necessary for its dendritic localization, thus revealing a mechanism for excitatory synapse development in the mammalian CNS.
authors.affiliation: Departments of Physiology, Biochemistry, and Biophysics, University of California, San Francisco, San Francisco, CA 94158, USA; Medical Research Council, National Institute for Medical Research, The Ridgeway, Mill Hill, London NW7 1AA, UK. Electronic address: sila.ultanir@nimr.mrc.ac.uk.
authors.forename: Sila K
authors.initials: SK
authors.lastname: Ultanir
authors.affiliation: Departments of Physiology, Biochemistry, and Biophysics, University of California, San Francisco, San Francisco, CA 94158, USA; Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA 94158, USA.
authors.forename: Smita
authors.initials: S
authors.lastname: Yadav
authors.affiliation: Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94158, USA; Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA 94158, USA.
authors.forename: Nicholas T
authors.initials: NT
authors.lastname: Hertz
authors.affiliation: Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, CA 94158, USA.
authors.forename: Juan A
authors.initials: JA
authors.lastname: Oses-Prieto
authors.affiliation: Medical Research Council, National Institute for Medical Research, The Ridgeway, Mill Hill, London NW7 1AA, UK.
authors.forename: Suzanne
authors.initials: S
authors.lastname: Claxton
authors.affiliation: Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, CA 94158, USA.
authors.forename: Alma L
authors.initials: AL
authors.lastname: Burlingame
authors.affiliation: Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94158, USA; Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA 94158, USA.
authors.forename: Kevan M
authors.initials: KM
authors.lastname: Shokat
authors.affiliation: Departments of Physiology, Biochemistry, and Biophysics, University of California, San Francisco, San Francisco, CA 94158, USA; Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA 94158, USA.
authors.forename: Lily Y
authors.initials: LY
authors.lastname: Jan
authors.affiliation: Departments of Physiology, Biochemistry, and Biophysics, University of California, San Francisco, San Francisco, CA 94158, USA; Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA 94158, USA. Electronic address: yuhnung.jan@ucsf.edu.
authors.forename: Yuh-Nung
authors.initials: YN
authors.lastname: Jan
mesh_terms: D000367:Age Factors; D000818:Animals; D002478:Cells, Cultured; D049229:Dendritic Spines / Q000378:metabolism*; D004622:Embryo, Mammalian; D018507:Gene Expression Regulation, Developmental / Q000235:genetics; D006624:Hippocampus / Q000166:cytology; D006801:Humans; D020930:MAP Kinase Kinase Kinases / Q000235:genetics / Q000378:metabolism*; D008869:Microtubule-Associated Proteins / Q000235:genetics / Q000378:metabolism; D009154:Mutation / Q000235:genetics; D018995:Myosin Heavy Chains / Q000378:metabolism*; D024701:Myosin Type V / Q000378:metabolism*; D009474:Neurons / Q000166:cytology*; D010766:Phosphorylation; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism*; D034741:RNA, Small Interfering / Q000235:genetics / Q000378:metabolism; D051381:Rats; D020318:Rats, Long-Evans; D013569:Synapses / Q000502:physiology*; D000099317:Hippo Kinases
chemical_list: D020930:MAP Kinase Kinase Kinases; D008869:Microtubule-Associated Proteins; D018995:Myosin Heavy Chains; D024701:Myosin Type V; D017346:Protein Serine-Threonine Kinases; D034741:RNA, Small Interfering; C489787:MAP2 protein, rat; C513081:Myo5a protein, rat; C109163:STK24 protein, human; D000099317:Hippo Kinases; C115483:TAO1 protein kinase; C122016:Taok2 protein, rat