title: Structure-function analysis of mouse Sry reveals dual essential roles of the C-terminal polyglutamine tract in sex determination.
abstract: The mammalian sex-determining factor SRY comprises a conserved high-mobility group (HMG) box DNA-binding domain and poorly conserved regions outside the HMG box. Mouse Sry is unusual in that it includes a C-terminal polyglutamine (polyQ) tract that is absent in nonrodent SRY proteins, and yet, paradoxically, is essential for male sex determination. To dissect the molecular functions of this domain, we generated a series of Sry mutants, and studied their biochemical properties in cell lines and transgenic mouse embryos. Sry protein lacking the polyQ domain was unstable, due to proteasomal degradation. Replacing this domain with irrelevant sequences stabilized the protein but failed to restore Sry's ability to up-regulate its key target gene SRY-box 9 (Sox9) and its sex-determining function in vivo. These functions were restored only when a VP16 transactivation domain was substituted. We conclude that the polyQ domain has important roles in protein stabilization and transcriptional activation, both of which are essential for male sex determination in mice. Our data disprove the hypothesis that the conserved HMG box domain is the only functional domain of Sry, and highlight an evolutionary paradox whereby mouse Sry has evolved a novel bifunctional module to activate Sox9 directly, whereas SRY proteins in other taxa, including humans, seem to lack this ability, presumably making them dependent on partner proteins(s) to provide this function.
authors: Division of Genomics of Development and Disease, Institute for Molecular Bioscience, The University of Queensland, St. Lucia, QLD 4072, Australia; and.
authors: Liang
authors: L
authors: Zhao
authors: Division of Genomics of Development and Disease, Institute for Molecular Bioscience, The University of Queensland, St. Lucia, QLD 4072, Australia; and.
authors: Ee Ting
authors: ET
authors: Ng
authors: Division of Genomics of Development and Disease, Institute for Molecular Bioscience, The University of Queensland, St. Lucia, QLD 4072, Australia; and.
authors: Tara-Lynne
authors: TL
authors: Davidson
authors: Division of Genomics of Development and Disease, Institute for Molecular Bioscience, The University of Queensland, St. Lucia, QLD 4072, Australia; and.
authors: Enya
authors: E
authors: Longmuss
authors: Institute for Biogenesis Research, Department of Anatomy, Biochemistry, and Physiology, John A. Burns School of Medicine, University of Hawaii, Honolulu, HI 96822.
authors: Johann
authors: J
authors: Urschitz
authors: Institute for Biogenesis Research, Department of Anatomy, Biochemistry, and Physiology, John A. Burns School of Medicine, University of Hawaii, Honolulu, HI 96822.
authors: Marlee
authors: M
authors: Elston
authors: Institute for Biogenesis Research, Department of Anatomy, Biochemistry, and Physiology, John A. Burns School of Medicine, University of Hawaii, Honolulu, HI 96822.
authors: Stefan
authors: S
authors: Moisyadi
authors: Division of Genomics of Development and Disease, Institute for Molecular Bioscience, The University of Queensland, St. Lucia, QLD 4072, Australia; and.
authors: Josephine
authors: J
authors: Bowles
authors: Division of Genomics of Development and Disease, Institute for Molecular Bioscience, The University of Queensland, St. Lucia, QLD 4072, Australia; and p.koopman@imb.uq.edu.au.
authors: Peter
authors: P
authors: Koopman
mesh_terms: D000818:Animals; D019143:Evolution, Molecular; D005260:Female; D017930:Genes, Reporter; D024282:Genes, sry; D008297:Male; D051379:Mice; D008822:Mice, Transgenic; D016296:Mutagenesis; D010446:Peptide Fragments / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D010455:Peptides / Q000737:chemistry; D011247:Pregnancy; D046988:Proteasome Endopeptidase Complex / Q000378:metabolism; D011489:Protein Denaturation; D055550:Protein Stability; D017434:Protein Structure, Tertiary; D055758:SOX9 Transcription Factor / Q000235:genetics / Q000378:metabolism; D017384:Sequence Deletion; D019849:Sex Determination Processes; D051876:Sex-Determining Region Y Protein / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D015533:Transcriptional Activation
chemical_list: D010446:Peptide Fragments; D010455:Peptides; D055758:SOX9 Transcription Factor; D051876:Sex-Determining Region Y Protein; C527933:Sox9 protein, mouse; C497746:Sry protein, mouse; C097188:polyglutamine; D046988:Proteasome Endopeptidase Complex
keywords: TESCO; Y chromosome; sex development; testis