IFIBYNE   05513
INSTITUTO DE FISIOLOGIA, BIOLOGIA MOLECULAR Y NEUROCIENCIAS
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Furry as a partner of the Ldb1-Lhx1 transcriptional complex for the specification of the renal progenitor cell field
Autor/es:
CIRIO, MC; FALL, JL; HO, J; HUKRIEDE, NEIL A.
Lugar:
PHILADELPHIA
Reunión:
Congreso; 2014 Kidney Week; 2014
Institución organizadora:
American Society of Nephrology
Resumen:
Background: In the vertebrate embryo, all renal progenitor cells and their descendants are derived from the intermediate mesoderm, a germ layer that lies between the lateral and paraxial mesoderm. Lhx1, a LIM-class homeobox transcription factor, is initially expressed throughout the lateral and intermediate mesoderm and is one of the earliest genes to be restricted to the kidney field. We have previously shown that Lhx1 is essential for driving specification of the entire kidney field from the intermediate mesoderm, but the molecular mechanism remains undefined. Transcriptional activity of Lhx1 in a tetrameric complex with Ldb1 protein is essential for kidney development, and studies have shown that the C-terminal regions of Lhx1 contain the functional domains necessary to confer transcriptional activity. Methods: By tandem affinity purification (TAP) of a full-length constitutive active form of Lhx1 (TAP-LL-CA) and a version lacking the c-terminal regions of Lhx1 (TAP-LL-ΔC) in a Xenopus kidney cell line, followed by LC-MS/MS, we identified the protein Furry (Fry) in interaction with LL-CA. In Xenopus, previous reports indicate that Fry acts as a transcriptional co-repressor of microRNAs preventing message degradation for Spemann organizer genes, temporally controlling their mRNA levels. We established the expression pattern of Fry by in situ hibridization and analyzed the effects of its depletion in pronephric kidney formation by using morpholinos. To investigate a possible mechanism of action for Fry and Lhx1 in the formation of the kidney field we performed MicroRNA deep sequencing on embryos depleted of the two proteins. Results: We found that fry is expressed in the intermediate mesoderm and developing pronephros. We determined that embryos depleted of fry by morpholino injections show almost complete loss of the kidney field, resembling the lhx1 depletion phenotype. We observed a synergistic effect of these two proteins on the intermediate mesoderm indicating the requirement of this interaction for the specification of the kidney progenitor cells. We identified miRNAs affected by the depletion of these proteins that might be in part responsible for the phenotype. Conclusions: These results suggest a role of Fry in the pronephric kidney development associated with the transcriptional activity of Lhx1 possibly through regulation of miRNAs expression.