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Abstract: FR-PO0768

Serine Protease High-Temperature Requirement Factor A1 (HTRA1) as a Potential Player in the FAK/YAP Pathway

Session Information

Category: Glomerular Diseases

  • 1401 Glomerular Diseases: Mechanisms, including Podocyte Biology

Authors

  • Demir, Fatih, Aarhus Universitet, Aarhus, Central Denmark Region , Denmark
  • Takayama, Suguru, University of Utah Health, Salt Lake City, Utah, United States
  • Beamish, Jeffrey A., University of Michigan, Ann Arbor, Michigan, United States
  • Naik, Abhijit S., University of Michigan, Ann Arbor, Michigan, United States
  • Beck, Laurence H., Boston University, Boston, Massachusetts, United States
  • Rinschen, Markus M., Aarhus Universitet, Aarhus, Central Denmark Region , Denmark
  • Al-Rabadi, Laith, University of Utah Health, Salt Lake City, Utah, United States
Background

HTRA1 coding variant (rs369149111) has been recently associated with 2.7 higher risk of negative outcome, defined as endpoint of 40% reduction in eGFR or ESRD, in the NEPTUNE glomerular disease cohort. KPMP Atlas shows the highest level of HTRA1 expression in podocytes, particularly those of a degenerative phenotype. Yes-associated protein (YAP), along with PDZ-binding motif (TAZ), are crucial for transducing of mechanical signals within the cellular microenvironment via their interactions with the actin cytoskeleton. Moreover, YAP1 can modulate WT1-dependent gene expression through its interaction with Wilms tumor protein 1-interacting protein. Herein, we investigated the link between HTRA1 and YAP1

Methods

Glomeruli from WT and HTRA1 KO mice were isolated using intra-aortic magnetic bead injection followed by N terminomic mass spectrometry to identify specific HTRA1 substrates and cleavage sites. In vitro digestion was used to confirm cleavage.

Results

YAP1 was predominantly cleaved in WT mice but not in HTRA1 KO mice. Confirmatory in vitro proteolytic analysis revealed that YAP1 is cleaved in vitro by WT HTRA1 but not mutant inactive HTRA1 at amino acid 122 (log2FC WT/HtrA1KO 9.8 with P value 4.6E-06). Key molecules of the YAP1 pathway including Focal adhesion kinase 1 and other focal adhesion proteins like Tensin 1 and 3, and slit diaphragm proteins like Alpha-parvin and Pard3B, PDLIM proteins and Cdc42 effector protein 1 were found to be degraded in WT mice but not HTRA1 KO mice. Wilms tumor protein 1-interacting protein (WTIP) was found to be cleaved almost exclusively in WT mice at AA 60 (log2FC WT/HtrA1KO, 2.24 with P value of 0.18).

Conclusion

These data would support a cellular mechanism by which HTRA1 cleaves key proteins involved in podocyte foot process signaling

Funding

  • NIDDK Support

Digital Object Identifier (DOI)