Protein phosphatase 2A modulates podocyte maturation and glomerular functional integrity in mice

Area of Science:

• Nephrology
• Molecular Biology
• Cell Biology

Background:

• Protein phosphorylation and dephosphorylation are key regulatory cellular processes.
• Protein Phosphatase 2A (PP2A) is widely expressed in kidney cells during development, but its specific roles are not fully understood.

Purpose of the Study:

• To elucidate the function of PP2A in kidney development and podocyte biology.
• To identify molecular targets of PP2A in podocytes.

Main Methods:

• Generated PP2A conditional knock-out mice (Pod-PP2A-KO) using Podocin-Cre and PP2A fl/fl mice.
• Utilized label-free nano-LC-MS/MS and SIEVE processing to identify PP2A targets in cultured podocytes.
• Employed Western blot and immunofluorescent staining for further analysis.

Main Results:

• Pod-PP2A-KO mice exhibited weight loss, growth retardation, proteinuria, and glomerulopathy.
• Observed foot process effacement, altered slit diaphragm molecule expression, and cytoskeleton rearrangement in podocytes.
• Identified Y box protein 1 (YB-1) as a dephosphorylation target of PP2A, with altered YB-1 phosphorylation in KO mice.

Conclusions:

• PP2A plays a vital role in foot process development and podocyte differentiation.
• PP2A-mediated dephosphorylation of YB-1 is critical for podocyte functional integrity.
• Fine-tuning YB-1 activity by PP2A is essential for maintaining the glomerular filtration barrier.