Reference - Detail
|Author||O'Brien LL, Grimaldi M, Kostun Z, Wingert RA, Selleck R, Davidson AJ.|
|Title||Wt1a, Foxc1a, and the Notch mediator Rbpj physically interact and regulate the formation of podocytes in zebrafish.|
Podocytes help form the glomerular blood filtration barrier in the kidney and their injury or loss leads to renal disease. The Wilms' tumor suppressor-1 (Wt1) and the FoxC1/2 transcription factors, as well as Notch signaling, have been implicated as important regulators of podocyte fate. It is not known whether these factors work in parallel or sequentially on different gene targets, or as higher-order transcriptional complexes on common genes. Here, we use the zebrafish to demonstrate that embryos treated with morpholinos against wt1a, foxc1a, or the Notch transcriptional mediator rbpj develop fewer podocytes, as determined by wt1b, hey1 and nephrin expression, while embryos deficient in any two of these factors completely lack podocytes. From GST-pull-downs and co-immunoprecipitation experiments we show that Wt1a, Foxc1a, and Rbpj can physically interact with each other, whereas only Rbpj binds to the Notch intracellular domain (NICD). In transactivation assays, combinations of Wt1, FoxC1/2, and NICD synergistically induce the Hey1 promoter, and have additive or repressive effects on the Podocalyxin promoter, depending on dosage. Taken together, these data suggest that Wt1, FoxC1/2, and Notch signaling converge on common target genes where they physically interact to regulate a podocyte-specific gene program. These findings further our understanding of the transcriptional circuitry responsible for podocyte formation and differentiation during kidney development.
|MeSH||Animals Base Sequence Basic Helix-Loop-Helix Transcription Factors / genetics Basic Helix-Loop-Helix Transcription Factors / metabolism Cell Differentiation DNA, Antisense / genetics Embryonic Stem Cells / cytology Embryonic Stem Cells / metabolism Forkhead Transcription Factors / antagonists & inhibitors Forkhead Transcription Factors / genetics Forkhead Transcription Factors / metabolism* Gene Expression Regulation, Developmental Gene Knockdown Techniques Immunoglobulin J Recombination Signal Sequence-Binding Protein / antagonists & inhibitors Immunoglobulin J Recombination Signal Sequence-Binding Protein / genetics Immunoglobulin J Recombination Signal Sequence-Binding Protein / metabolism* Kidney / cytology Kidney / embryology Kidney / metabolism Models, Biological Podocytes / cytology* Podocytes / metabolism* Promoter Regions, Genetic Protein Interaction Domains and Motifs Receptors, Notch / metabolism* Repressor Proteins / genetics Repressor Proteins / metabolism Signal Transduction WT1 Proteins / antagonists & inhibitors WT1 Proteins / genetics WT1 Proteins / metabolism* Zebrafish / embryology* Zebrafish / genetics Zebrafish / metabolism* Zebrafish Proteins / antagonists & inhibitors Zebrafish Proteins / genetics Zebrafish Proteins / metabolism*|
|WOS Category||DEVELOPMENTAL BIOLOGY|
|DNA material||pCMX-N/RBP-J (RDB03021) pEF-BOSneo-mNotch1 RAMIC (RDB06771) TP1-luc(981-6) (a.k.a. pGa981-6) (RDB06776).|