Project description:Songbirds possess one of the most accessible neural systems for the study of brain mechanisms of behavior. However, neuroethological studies in songbirds have been limited by the lack of high-throughput molecular resources and gene manipulation tools. To overcome this limitation, here we generated a resource of full-length cDNAs for gene expression analyses and gene manipulation in songbirds. We constructed 21 regular, normalized, and subtracted full-length cDNA libraries from brains of songbirds in 57 behavioral and developmental conditions in an attempt to clone as much of the brain transcriptome as possible. From these libraries ~14,000 transcripts were isolated, representing an estimated 4,738 genes, or ~40% of the genes expressed in the brain. With these cDNAs, we created a novel draft transcriptome database and large scale songbird brain cDNA microarrays. We used the arrays to reveal a set of 33 genes regulated in brain vocal nuclei by singing behavior. These genes clustered into 4 anatomical and 6 temporal brain expression patterns. Their functions spanned broad range of cellular and molecular categories, including signal transduction, trafficking, structural, and synaptically released molecules. With the full-length cDNAs, we over-expressed proteins of representative singing-regulated genes in vocal nuclei in the absence of singing, using a lentiviral vector system. This resource now allows investigators to comprehensively study molecular neuroethological mechanisms of behavior. Keywords: songbird, zebra finch, transcriptome, learned vocalization, immediate early genes, lentivirus
Project description:These data correspond to one SMRT cell sequencing run (performed on Sequel II, PacBio) of full length cDNAs from 3 pooled glioma stem cell line libraries. No tag was added to distinguish the 3 different samples
Project description:Kynureninase is a member of a large family of catalytically diverse but structurally homologous pyridoxal 5'-phosphate (PLP) dependent enzymes known as the aspartate aminotransferase superfamily or alpha-family. The Homo sapiens and other eukaryotic constitutive kynureninases preferentially catalyze the hydrolytic cleavage of 3-hydroxy-l-kynurenine to produce 3-hydroxyanthranilate and l-alanine, while l-kynurenine is the substrate of many prokaryotic inducible kynureninases. The human enzyme was cloned with an N-terminal hexahistidine tag, expressed, and purified from a bacterial expression system using Ni metal ion affinity chromatography. Kinetic characterization of the recombinant enzyme reveals classic Michaelis-Menten behavior, with a Km of 28.3 +/- 1.9 microM and a specific activity of 1.75 micromol min-1 mg-1 for 3-hydroxy-dl-kynurenine. Crystals of recombinant kynureninase that diffracted to 2.0 A were obtained, and the atomic structure of the PLP-bound holoenzyme was determined by molecular replacement using the Pseudomonas fluorescens kynureninase structure (PDB entry 1qz9) as the phasing model. A structural superposition with the P. fluorescens kynureninase revealed that these two structures resemble the "open" and "closed" conformations of aspartate aminotransferase. The comparison illustrates the dynamic nature of these proteins' small domains and reveals a role for Arg-434 similar to its role in other AAT alpha-family members. Docking of 3-hydroxy-l-kynurenine into the human kynureninase active site suggests that Asn-333 and His-102 are involved in substrate binding and molecular discrimination between inducible and constitutive kynureninase substrates.