title: N-twist, an evolutionarily conserved bHLH protein expressed in the developing CNS, functions as a transcriptional inhibitor.
abstract: Members of the basic helix-loop-helix (bHLH) transcription factor family play an essential role in multiple developmental processes. During neurogenesis, positive and negative regulation by bHLH proteins is essential for proper development. Here we report the identification and initial characterization of the bHLH gene, Neuronal twist (N-twist), named for its neural expression pattern and high sequence homology and physical linkage to the mesodermal inhibitor, M-twist. N-twist is expressed in the developing mouse central nervous system in the midbrain, hindbrain, and neural tube. This neural expression is conserved in invertebrates, as expression of the Drosophila ortholog of N-twist is also restricted to the central nervous system. Like other bHLH family members, N-Twist heterodimerizes with E protein and binds DNA at a consensus bHLH-binding site, the E box. We show that N-Twist inhibits MASH1-dependent transcriptional activation by sequestering E protein in a dominant negative fashion. Thus, these studies support the notion that N-Twist represents a novel negative regulator of neurogenesis.
authors.affiliation: Cardiovascular Research Institute, Univerity of California, San Francisco, California 94143-0130, USA.
authors.forename: Michael P
authors.initials: MP
authors.lastname: Verzi
authors.forename: Joshua P
authors.initials: JP
authors.lastname: Anderson
authors.forename: Evdokia
authors.initials: E
authors.lastname: Dodou
authors.forename: Kathleen K
authors.initials: KK
authors.lastname: Kelly
authors.forename: Stephanie B
authors.initials: SB
authors.lastname: Greene
authors.forename: Brian J
authors.initials: BJ
authors.lastname: North
authors.forename: Richard M
authors.initials: RM
authors.lastname: Cripps
authors.forename: Brian L
authors.initials: BL
authors.lastname: Black
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D051792:Basic Helix-Loop-Helix Proteins; D002490:Central Nervous System / Q000196:embryology* / Q000254:growth & development; D003001:Cloning, Molecular; D017124:Conserved Sequence; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D019281:Dimerization; D004330:Drosophila / Q000235:genetics; D029721:Drosophila Proteins / Q000235:genetics* / Q000378:metabolism*; D019143:Evolution, Molecular; D005260:Female; D018507:Gene Expression Regulation, Developmental; D018257:Helix-Loop-Helix Motifs; D006801:Humans; D051379:Mice; D008969:Molecular Sequence Data; D018006:Myogenic Regulatory Factors; D009419:Nerve Tissue Proteins; D009687:Nuclear Proteins / Q000235:genetics; D012097:Repressor Proteins; D051820:TCF Transcription Factors; D058125:Transcription Factor 7-Like 1 Protein; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism*; D014158:Transcription, Genetic; D051879:Twist-Related Protein 1
chemical_list: D051792:Basic Helix-Loop-Helix Proteins; D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; D018006:Myogenic Regulatory Factors; D009419:Nerve Tissue Proteins; D009687:Nuclear Proteins; D012097:Repressor Proteins; D051820:TCF Transcription Factors; D058125:Transcription Factor 7-Like 1 Protein; D014157:Transcription Factors; D051879:Twist-Related Protein 1; C065500:ASCL1 protein, human; C499317:Ascl1 protein, mouse; C486163:FERD3L protein, human; C435755:Fer3 protein, Drosophila; C544912:TCF7L1 protein, human; C544913:Tcf7l1 protein, mouse; C067250:Twist1 protein, mouse