%0 Journal Article %A Miller, Raymond R. %A Okkema, Peter G. %D 2012 %T The Caenorhabditis elegans T-Box Factor MLS-1 Requires Groucho Co-Repressor Interaction for Uterine Muscle Specification %U https://indigo.uic.edu/articles/journal_contribution/The_Caenorhabditis_elegans_T-Box_Factor_MLS-1_Requires_Groucho_Co-Repressor_Interaction_for_Uterine_Muscle_Specification/10770278 %2 https://indigo.uic.edu/ndownloader/files/19282919 %K transcription %K mechanism %X T-box proteins are conserved transcription factors that play crucial roles in development of all metazoans; and, in humans, mutations affecting T-box genes are associated with a variety of congenital diseases and cancers. Despite the importance of this transcription factor family, very little is known regarding how T-box factors regulate gene expression. The Caenorhabditis elegans genome contains 21 T-box genes, and their characterized functions include cell fate specification in a variety of tissues. The C. elegans Tbx1 sub-family member MLS-1 functions during larval development to specify the fate of non-striated uterine muscles; and, in mls-1 mutants, uterine muscles are transformed to a vulval muscle fate. Here we demonstrate that MLS-1 function depends on binding to the Groucho-family co-repressor UNC-37. MLS-1 interacts with UNC-37 via a conserved eh1 motif, and the MLS-1 eh1 motif is necessary for MLS-1 to specify uterine muscle fate. Moreover, unc-37 loss-of-function produces uterine muscle to vulval muscle fate transformation similar to those observed in mls-1 mutants. Based on these results, we conclude that MLS-1 specifies uterine muscle fate by repressing target gene expression, and this function depends on interaction with UNC-37. Moreover, we suggest that MLS-1 shares a common mechanism for transcriptional repression with related T-box factors in other animal phyla. %I University of Illinois at Chicago