Gene regulatory functions of Drosophila Fish-hook, a high mobility group domain Sox protein

• Published in: Mechanisms of development 1998-05, Vol.73 (2), p.169-182
• Main Authors: Ma, Yue, Niemitz, Emily L, Nambu, Patricia A, Shan, Xiaoliang, Sackerson, Charles, Fujioka, Miki, Goto, Tadaatsu, Nambu, John R
• Format: Article
• Language: English
• Subjects: Animals; Base Sequence; DNA Primers; DNA-Binding Proteins - physiology; Drosophila; Drosophila - embryology; Drosophila - genetics; Drosophila Proteins; Gene Expression Regulation, Developmental - physiology; High Mobility Group Proteins - physiology; HMG domain; Sox gene; SOX Transcription Factors; Transcription Factors - physiology; Transcriptional Activation - physiology; Transcriptional regulation
• ISSN: 0925-4773; 1872-6356
• DOI: 10.1016/S0925-4773(98)00050-1

In this study we investigate the gene regulatory functions of Drosophila Fish-hook (Fish), a high mobility group (HMG) Sox protein that is essential for embryonic segmentation. We show that the Fish HMG domain binds to the vertebrate Sox protein consensus DNA binding sites, AACAAT and AACAAAG, and that this binding induces an 85° DNA bend. In addition, we use a heterologous yeast system to show that the NH2-terminal portion of Fish protein can function as a transcriptional activator. Fish directly regulates the expression of the pair rule gene, even-skipped (eve), by binding to multiple sites located in downstream regulatory regions that direct formation of eve stripes 1, 4, 5, and 6. Fish may function along with the Drosophila POU domain proteins Pdm-1 and Pdm-2 to regulate eve transcription, as genetic interactions were detected between fish and pdm mutants. Finally, we determined that Fish protein is expressed in a dynamic pattern throughout embryogenesis, and is present in nuclear and cytoplasmic compartments.