Skip to main content
Article thumbnail
Location of Repository

Akirin Links Twist-Regulated Transcription with the Brahma Chromatin Remodeling Complex during Embryogenesis

By Scott J. Nowak, Hitoshi Aihara, Katie Gonzalez, Yutaka Nibu and Mary K. Baylies


The activities of developmentally critical transcription factors are regulated via interactions with cofactors. Such interactions influence transcription factor activity either directly through protein–protein interactions or indirectly by altering the local chromatin environment. Using a yeast double-interaction screen, we identified a highly conserved nuclear protein, Akirin, as a novel cofactor of the key Drosophila melanogaster mesoderm and muscle transcription factor Twist. We find that Akirin interacts genetically and physically with Twist to facilitate expression of some, but not all, Twist-regulated genes during embryonic myogenesis. akirin mutant embryos have muscle defects consistent with altered regulation of a subset of Twist-regulated genes. To regulate transcription, Akirin colocalizes and genetically interacts with subunits of the Brahma SWI/SNF-class chromatin remodeling complex. Our results suggest that, mechanistically, Akirin mediates a novel connection between Twist and a chromatin remodeling complex to facilitate changes in the chromatin environment, leading to the optimal expression of some Twist-regulated genes during Drosophila myogenesis. We propose that this Akirin-mediated link between transcription factors and the Brahma complex represents a novel paradigm for providing tissue and target specificity for transcription factor interactions with the chromatin remodeling machinery

Topics: Research Article
Publisher: Public Library of Science
OAI identifier:
Provided by: PubMed Central
Download PDF:
Sorry, we are unable to provide the full text but you may find it at the following location(s):
  • http://www.pubmedcentral.nih.g... (external link)
  • Suggested articles


    1. (2010). 14-3-3 mediates histone cross-talk during transcription elongation in Drosophila.
    2. (2007). A core transcriptional network for early mesoderm development in Drosophila melanogaster.
    3. (1997). A direct contact between the dorsal rel homology domain and Twist may mediate transcriptional synergy.
    4. (1999). A double interaction screen identifies positive and negative ftz gene regulators and ftz-interacting proteins.
    5. (2002). A misexpression study examining dorsal thorax formation in Drosophila melanogaster.
    6. (2001). A new mathematical model for relative quantification in realtime RT-PCR.
    7. (2003). A protein interaction map of Drosophila melanogaster.
    8. (2001). A rapid method to map mutations in Drosophila.
    9. (1995). A series of mutations in the D-MEF2 transcription factor reveal multiple functions in larval and adult myogenesis in Drosophila.
    10. (2006). A temporal map of transcription factor activity: mef2 directly regulates target genes at all stages of muscle development.
    11. (2002). A Twist in fate: evolutionary comparison of Twist structure and function.
    12. (2009). A twist of insight - the role of Twist-family bHLH factors in development.
    13. (2009). Akirin1 (Mighty), a novel promyogenic factor regulates muscle regeneration and cell chemotaxis.
    14. (1975). Analysis of drosophila mRNA by in situ hybridization: sequences transcribed in normal and heat shocked cultured cells.
    15. (2005). bhringi: A novel Twist co-regulator.
    16. (2005). Charlatan, a Zn-finger transcription factor, establishes a novel level of regulation of the proneural achaete/scute genes of Drosophila.
    17. (2005). Composition and functional specificity of SWI2/SNF2 class chromatin remodeling complexes.
    18. Corces VG (2000) Phosphorylation of histone H3 correlates with transcriptionally active loci.
    19. (1994). D-MEF2: a MADS box transcription factor expressed in differentiating mesoderm and muscle cell lineages during Drosophila embryogenesis.
    20. (2008). Daughterless dictates Twist activity in a context-dependent manner during somatic myogenesis.
    21. (1999). Different levels, but not different isoforms, of the Drosophila transcription factor DMEF2 affect distinct aspects of muscle differentiation.
    22. (2001). Dimerization partners determine the activity of the Twist bHLH protein during Drosophila mesoderm development.
    23. (1992). Dorsoventral development of the Drosophila embryo is controlled by a cascade of transcriptional regulators. Dev Suppl.
    24. (1998). Drosophila mef2 expression during mesoderm development is controlled by a complex array of cis-acting regulatory modules.
    25. (1995). Drosophila MEF2 is regulated by twist and is expressed in both the primordia and differentiated cells of the embryonic somatic, visceral and heart musculature.
    26. (1995). Drosophila MEF2, a transcription factor that is essential for myogenesis.
    27. (2009). Evolution of the multifaceted eukaryotic akirin gene family.
    28. (1997). eyelid antagonizes wingless signaling during Drosophila development and has homology to the Bright family of DNA-binding proteins.
    29. (1998). Genetic analysis of brahma: the Drosophila homolog of the yeast chromatin remodeling factor SWI2/SNF2.
    30. (1994). Genetic analysis of the brahma gene of Drosophila melanogaster and polytene chromosome subdivisions 72AB.
    31. (1993). Interactions between dorsal and helixloop-helix proteins initiate the differentiation of the embryonic mesoderm and neuroectoderm in Drosophila.
    32. (2005). Ja ¨ckle H
    33. (2005). Mapping Dmef2-binding regulatory modules by using a ChIP-enriched in silico targets approach.
    34. (1983). Maternal-Zygotic Gene Interactions during Formation of the Dorsoventral Pattern in Drosophila Embryos.
    35. (2008). mef2 activity levels differentially affect gene expression during Drosophila muscle development.
    36. (2008). Message in a nucleus: signaling to the transcriptional machinery. Current Opinion
    37. (2008). Mighty is a novel promyogenic factor in skeletal myogenesis.
    38. (1993). Multiple RNA regulatory elements mediate distinct steps in localization of oskar mRNA.
    39. (2010). Muscle wasted: a novel component of the Drosophila histone locus body required for muscle integrity.
    40. (2007). Myogenin and the SWI/SNF ATPase Brg1 maintain myogenic gene expression at different stages of skeletal myogenesis.
    41. (2009). Nap1-mediated actin remodeling is essential for mammalian myoblast fusion.
    42. (2002). New fluorescent protein reporters for use with the Drosophila Gal4 expression system and for vital detection of balancer chromosomes.
    43. (1999). Osa associates with the Brahma chromatin remodeling complex and promotes the activation of some target genes.
    44. (2000). Osa-containing Brahma chromatin remodeling complexes are required for the repression of wingless target genes.
    45. (2003). Overexpression of the SuUR gene induces reversible modifications at pericentric, telomeric and intercalary heterochromatin of Drosophila melanogaster polytene chromosomes.
    46. (2006). Parcas, a regulator of non-receptor tyrosine kinase signaling, acts during anterior-posterior patterning and somatic muscle development in Drosophila melanogaster.
    47. (2010). Pivotal role of Twist in skeletal biology and pathology.
    48. (2003). Protein phosphatase 2A activity affects histone H3 phosphorylation and transcription in Drosophila melanogaster.
    49. (2000). Ras pathway specificity is determined by the integration of multiple signalactivated and tissue-restricted transcription factors.
    50. (1997). Regulation of the twist target gene tinman by modular cis-regulatory elements during early mesoderm development.
    51. (2007). SCAR/WAVE and Arp2/3 are crucial for cytoskeletal remodeling at the site of myoblast fusion.
    52. (2005). Specification of individual Slouch muscle progenitors in Drosophila requires sequential Wingless signaling.
    53. (2010). Specificity of Notch pathway activation: Twist controls the transcriptional output in adult muscle progenitors.
    54. (1993). Targeted gene expression as a means of altering cell fates and generating dominant phenotypes.
    55. (2007). The acetyltransferase activity of Drosophila CBP is dispensable for regulation of the Dpp pathway in the early embryo.
    56. (1996). The autosomal FLP-DFS technique for generating germline mosaics in Drosophila melanogaster.
    57. (2009). The Biology of Chromatin Remodeling Complexes.
    58. (1991). The dorsal morphogen gradient regulates the mesoderm determinant twist in early Drosophila embryos.
    59. (2002). The Drosophila BRM complex facilitates global transcription by RNA polymerase II.
    60. (1997). The Drosophila homeotic gene moira regulates expression of engrailed and HOM genes in imaginal tissues.
    61. (2006). The Drosophila P68 RNA helicase regulates transcriptional deactivation by promoting RNA release from chromatin.
    62. (1990). The embryonic development of larval muscles in Drosophila.
    63. (1998). The myogenic regulatory gene Mef2 is a direct target for transcriptional activation by Twist during Drosophila myogenesis.
    64. (2008). The Transcriptional Coactivator SAYP Is a Trithorax Group Signature Subunit of the PBAP Chromatin Remodeling Complex.
    65. (1999). The trithorax group gene moira encodes a brahma-associated putative chromatinremodeling factor in Drosophila melanogaster.
    66. (2009). Transcription coactivator SAYP combines chromatin remodeler Brahma and transcription initiation factor TFIID into a single supercomplex.
    67. (1991). twist and snail as positive and negative regulators during Drosophila mesoderm development.
    68. (2004). Twist, a master regulator of morphogenesis, plays an essential role in tumor metastasis.
    69. (1996). twist: a myogenic switch in Drosophila.
    70. (2008). Two subunits specific to the PBAP chromatin remodeling complex have distinct and redundant functions during drosophila development.
    71. (2009). Unlocking the secrets of the genome.
    72. (2007). Wholegenome ChIP-chip analysis of Dorsal, Twist, and Snail suggests integration of diverse patterning processes in the Drosophila embryo.

    To submit an update or takedown request for this paper, please submit an Update/Correction/Removal Request.