Abstract
Ptx1 (Pitx1) is a bicoid-related homeobox transcription factor expressed from the onset of pituitary development. It was shown to cooperate with cell-restricted factors, such as Pit1, NeuroD1/PanI and steroidogenic factor 1 (SF-1), to establish a combinatorial code conferring lineage- and promoter-specific gene transcription in the pituitary. Transcriptional synergism between Ptx1 and SF-1 on two SF-1 target genes, pituitary luteinizing hormone beta and Müllerian-inhibiting substance (MIS), requires SF-1 binding to DNA and appears to result from direct physical interaction between these two proteins. The interaction between the C-terminus of Ptx1 and the N-terminal half of SF-1 results in transcriptional enhancement that equals the activity of a constitutively active SF-1 mutant and that may mimic the effect of a still unidentified SF-1 ligand. Thus, the unmasking of SF-1 activity by Ptx1 may represent a developmental mechanism to alleviate the need for SF-1 ligand in transcription and, possibly, at critical times during organogenesis.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Animals
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Anti-Mullerian Hormone
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Binding Sites
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Cell Line
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Chlorocebus aethiops
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DNA / genetics
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DNA / metabolism
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DNA-Binding Proteins / genetics
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DNA-Binding Proteins / metabolism*
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Fushi Tarazu Transcription Factors
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Glycoproteins*
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Growth Inhibitors / genetics
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Homeodomain Proteins / genetics
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Homeodomain Proteins / metabolism*
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L Cells
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Ligands
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Luteinizing Hormone / genetics
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Mice
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Models, Genetic
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Paired Box Transcription Factors
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Promoter Regions, Genetic / genetics
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Protein Binding
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Receptors, Cytoplasmic and Nuclear
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Response Elements / genetics
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Sequence Deletion
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Steroidogenic Factor 1
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Testicular Hormones / genetics
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Transcription Factors / genetics
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Transcription Factors / metabolism*
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Transcriptional Activation*
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Transfection
Substances
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DNA-Binding Proteins
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Fushi Tarazu Transcription Factors
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Glycoproteins
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Growth Inhibitors
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Homeodomain Proteins
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Ligands
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Paired Box Transcription Factors
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Receptors, Cytoplasmic and Nuclear
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Steroidogenic Factor 1
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Testicular Hormones
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Transcription Factors
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homeobox protein PITX1
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steroidogenic factor 1, mouse
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Anti-Mullerian Hormone
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Luteinizing Hormone
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DNA