Xenopus Ssbp2 is required for embryonic pronephros morphogenesis and terminal differentiation

Area of Science:

• Developmental Biology
• Molecular Biology
• Genetics

Background:

• The nephron is the functional unit of the kidney, essential for waste excretion and osmoregulation.
• The Xenopus laevis pronephric kidney serves as a simplified model for studying nephrogenesis due to conserved gene expression.
• The transcription factor Lhx1, complexed with LIM binding protein 1 (Ldb1), is vital for embryogenesis, but its kidney-specific cofactors are poorly understood.

Purpose of the Study:

• To identify novel cofactors of the Ldb1-Lhx1 complex involved in kidney organogenesis.
• To investigate the role of identified cofactors in nephrogenesis using the Xenopus model.

Main Methods:

• Tandem-affinity purification from kidney-induced Xenopus animal caps.
• Identification of interacting proteins with the Ldb1-Lhx1 complex.
• Knockdown experiments to assess the function of identified proteins in pronephros development.

Main Results:

• Single-stranded DNA binding protein 2 (Ssbp2) was identified as an interactor of the Ldb1-Lhx1 complex.
• Ssbp2 is expressed in the developing Xenopus pronephros.
• Knockdown of Ssbp2 disrupted the normal morphogenesis and differentiation of the glomus and renal tubules.

Conclusions:

• A member of the Ssbp family, Ssbp2, plays a significant role in kidney organogenesis.
• The Ldb1-Lhx1-Ssbp transcriptional complex is fundamentally important for embryonic kidney development.