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Cytoskeletal protein vimentin interacts with and regulates peroxisome proliferator‐activated receptor gamma via a proteasomal degradation process
Author(s) -
Tsai YunChih,
Tsai ShuHuei,
Chang Emily YunChia,
Hee SiowWey,
Chen WeiHao,
Lee ShengChung,
Chuang LeeMing
Publication year - 2013
Publication title -
journal of cellular biochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.028
H-Index - 165
eISSN - 1097-4644
pISSN - 0730-2312
DOI - 10.1002/jcb.24497
Subject(s) - vimentin , microbiology and biotechnology , immunoprecipitation , peroxisome proliferator activated receptor , endoplasmic reticulum , cytoskeleton , transcription factor , cytosol , receptor , chromatin immunoprecipitation , golgi apparatus , biology , chemistry , biochemistry , cell , gene expression , promoter , gene , immunohistochemistry , immunology , enzyme
Peroxisome proliferators‐activated receptor gamma (PPARγ) receptor is a transcription factor that is located in and functions primarily in the nucleus. PPARγ is exported from the nucleus upon mitogen and ligand stimulation under certain circumstances. However, a cytoplasmic PPARγ interacting protein and its function have not been previously identified. Here, we report for the first time that cytosolic PPARγ interacts directly with cytoskeletal vimentin. We performed PPARγ immunoprecipitation followed by mass spectrometry to identify the vimentin‐PPARγ complex. This interaction was confirmed by reciprocal vimentin and PPARγ immunoprecipitation and co‐immunofluorescence examination. We demonstrated that PPARγ colocalized with vimentin in certain organelles that is golgi, mitochondria, and endoplasmic reticulum. In cells depleted of vimentin, PPARγ was ubiquitinated and targeted to a proteasomal degradation pathway. Together, these findings indicate a direct interaction of PPARγ with vimentin in the cytosolic compartment, in which vimentin appears to play a role in regulating the turnover rate of PPARγ, which may further regulate genomic or non‐genomic activities through the regulation of PPARγ protein degradation. J. Cell. Biochem. 114: 1559–1567, 2013. © 2013 Wiley Periodicals, Inc.