A calreticulin-dependent nuclear export signal is involved in the regulation of liver receptor homologue-1 protein folding

Feng Ming Yang, Shan Jung Feng, Tsai Chun Lai, Meng Chun Hu

研究成果: 雜誌貢獻文章

5 引文 斯高帕斯(Scopus)

摘要

As an orphan member of the nuclear receptor family, liver receptor homologue-1 (LRH-1) controls a tremendous range of transcriptional programmes that are essential for metabolism and hormone synthesis. Our previous studies have shown that nuclear localization of the LRH-1 protein is mediated by two nuclear localization signals (NLSs) that are karyopherin/importindependent. It is unclear whether LRH-1 can be actively exported from the nucleus to the cytoplasm. In the present study, we describe a nuclear export domain containing two leucine-rich motifs [named nuclear export signal (NES)1 and NES2] within the ligand-binding domain (LBD). Mutation of leucine residues in NES1 or NES2 abolished nuclear export, indicating that both NES1 and NES2 motifs are essential for full nuclear export activity. This NES-mediated nuclear export was insensitive to the chromosomal regionmaintenance 1 (CRM1) inhibitor leptomycin B (LMB) or to CRM1 knockdown. However, knockdown of calreticulin (CRT) prevented NES-mediated nuclear export. Furthermore, our data show that CRT interacts with LRH-1 and is involved in the nuclear export of LRH-1. With full-length LRH-1, mutation of NES1 led to perinuclear accumulation of the mutant protein. Immunofluorescence analysis showed that these perinuclear aggregates were co-localized with the centrosome marker, microtubule-associated protein 1 light chain 3(LC3), ubiquitin and heat shock protein 70 (Hsp70), indicating that the mutant was misfolded and sequestered into aggresomelike structures via the autophagic clearance pathway. Our study demonstrates for the first time that LRH-1 has a CRT-dependent NES which is not only required for cytoplasmic trafficking, but also essential for correct protein folding to avoid misfoldinginduced aggregation.
原文英語
頁(從 - 到)199-209
頁數11
期刊Biochemical Journal
471
發行號2
DOIs
出版狀態已發佈 - 十月 15 2015
對外發佈Yes

ASJC Scopus subject areas

  • Biochemistry
  • Molecular Biology
  • Cell Biology

指紋 深入研究「A calreticulin-dependent nuclear export signal is involved in the regulation of liver receptor homologue-1 protein folding」主題。共同形成了獨特的指紋。

  • 引用此