Journal
JOURNAL OF EXPERIMENTAL MEDICINE
Volume 213, Issue 6, Pages 1029-1046Publisher
ROCKEFELLER UNIV PRESS
DOI: 10.1084/jem.20151229
Keywords
-
Categories
Funding
- National Institutes of Health [HL116472, HL126990, HL114453]
- University of Pittsburgh Vascular Medicine Institute seed fund
Ask authors/readers for more resources
The E3 small ubiquitin-like modifier (SUMO) protein ligase protein inhibitor of activated STAT 4 (PIAS4) is a pivotal protein in regulating the TGF beta pathway. In this study, we discovered a new protein isoform encoded by KIAA0317, termed fibrosis-inducing E3 ligase 1 (FIEL1), which potently stimulates the TGF beta signaling pathway through the site-specific ubiquitination of PIAS4. FIEL1 targets PIAS4 using a double locking mechanism that is facilitated by the kinases PKC zeta and GSK3 beta. Specifically, PKC zeta phosphorylation of PIAS4 and GSK3 beta phosphorylation of FIEL1 are both essential for the degradation of PIAS4. FIEL1 protein is highly expressed in lung tissues from patients with idiopathic pulmonary fibrosis (IPF), whereas PIAS4 protein levels are significantly reduced. FIEL1 overexpression significantly increases fibrosis in a bleomycin murine model, whereas FIEL1 knockdown attenuates fibrotic conditions. Further, we developed a first-in-class small molecule inhibitor toward FIEL1 that is highly effective in ameliorating fibrosis in mice. This study provides a basis for IPF therapeutic intervention by modulating PIAS4 protein abundance.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available