Cytoplasmic metadherin (MTDH) provides survival advantage under conditions of stress by acting as RNA-binding protein

Xiangbing Meng, Danlin Zhu, Shujie Yang, Xinjun Wang, Zhi Xiong, Yuping Zhang, Pavla Brachova, Kimberly K. Leslie

Research output: Contribution to journalArticlepeer-review

Abstract

Overexpression of metadherin (MTDH) has been documented in many solid tumors and is implicated in metastasis and chemoresistance. MTDH has been detected at the plasma membrane as well as in the cytoplasm and nucleus, and the function of MTDH in these locales remains under investigation. In the nucleus, MTDH acts as a transcription co-factor to induce expression of chemoresistance-associated genes. However, MTDH is predominantly cytoplasmic in prostate tumors, and this localization correlates with poor prognosis. Herein, we used endometrial cancer cells as a model system to define a new role for MTDH in the cytoplasm. First, MTDH was primarily localized to the cytoplasm in endometrial cancer cells, and the N-terminal region of MTDH was required to maintain cytoplasmic localization. Next, we identified novel binding partners for cytoplasmic MTDH, including RNA-binding proteins and components of the RNA-induced silencing complex. Nucleic acids were required for the association of MTDH with these cytoplasmic proteins. Furthermore, MTDH interacted with and regulated protein expression of multiple mRNAs, such as PDCD10 and KDM6A. Depletion of cytoplasmic MTDH was associated with increased stress granule formation, reduced survival in response to chemotherapy and the tyrosine kinase inhibitor BIBF1120, Rad51 nuclear accumulation, and cell cycle arrest at G 2/M. Finally, in vivo tumor formation was abrogated with knockdown of cytoplasmic MTDH. Taken together, our data identify a novel function for cytoplasmic MTDH as an RNA-binding protein. Our findings implicate cytoplasmic MTDH in cell survival and broad drug resistance via association with RNA and RNA-binding proteins.

Original languageEnglish (US)
Pages (from-to)4485-4491
Number of pages7
JournalJournal of Biological Chemistry
Volume287
Issue number7
DOIs
StatePublished - Feb 10 2012

ASJC Scopus subject areas

  • Biochemistry
  • Molecular Biology
  • Cell Biology

Fingerprint

Dive into the research topics of 'Cytoplasmic metadherin (MTDH) provides survival advantage under conditions of stress by acting as RNA-binding protein'. Together they form a unique fingerprint.

Cite this