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Distinct functional domains of PNMA5 mediate protein-protein interaction, nuclear localization, and apoptosis signaling in human cancer cells.
- Source :
-
Journal of cancer research and clinical oncology [J Cancer Res Clin Oncol] 2016 Sep; Vol. 142 (9), pp. 1967-77. Date of Electronic Publication: 2016 Jul 16. - Publication Year :
- 2016
-
Abstract
- Purpose: Members of paraneoplastic Ma (PNMA) family have been identified as onconeuronal antigens, which aberrant expressions in cancer cells of patients with paraneoplastic disorder (PND) are closely linked to manifestation of auto-immunity, neuro-degeneration, and cancer. The purpose of present study was to determine the role of PNMA5 and its functional relationship to MOAP-1 (PNMA4) in human cancer cells.<br />Methods: PNMA5 mutants were generated through deletion or site-directed mutagenesis and transiently expressed in human cancer cell lines to investigate their role in apoptosis, subcellular localization, and potential interaction with MOAP-1 through apoptosis assays, fluorescence microscopy, and co-immunoprecipitation studies, respectively.<br />Results: Over-expressed human PNMA5 exhibited nuclear localization pattern in both MCF-7 and HeLa cells. Deletion mapping and mutagenesis studies showed that C-terminus of PNMA5 is responsible for nuclear localization, while the amino acid residues (391KRRR) within the C-terminus of PNMA5 are required for nuclear targeting. Deletion mapping and co-immunoprecipitation studies showed that PNMA5 interacts with MOAP-1 and N-terminal domain of PNMA5 is required for interaction with MOAP-1. Furthermore, co-expression of PNMA5 and MOAP-1 in MCF-7 cells significantly enhanced chemo-sensitivity of MCF-7 to Etoposide treatment, indicating that PNMA5 and MOAP-1 interact synergistically to promote apoptotic signaling in MCF-7 cells.<br />Conclusions: Our results show that PNMA5 promotes apoptosis signaling in HeLa and MCF-7 cells and interacts synergistically with MOAP-1 through its N-terminal domain to promote apoptosis and chemo-sensitivity in human cancer cells. The C-terminal domain of PNMA5 is required for nuclear localization; however, both N-and C-terminal domains of PNMA5 appear to be required for pro-apoptotic function.
- Subjects :
- Active Transport, Cell Nucleus genetics
Adaptor Proteins, Signal Transducing genetics
Antigens, Neoplasm genetics
Antigens, Neoplasm metabolism
Apoptosis Regulatory Proteins genetics
HEK293 Cells
HeLa Cells
Humans
MCF-7 Cells
Mutagenesis, Site-Directed
Protein Interaction Domains and Motifs genetics
Protein Interaction Maps
Protein Transport genetics
Signal Transduction physiology
Adaptor Proteins, Signal Transducing chemistry
Antigens, Neoplasm chemistry
Apoptosis genetics
Apoptosis Regulatory Proteins chemistry
Cell Nucleus metabolism
Protein Interaction Domains and Motifs physiology
Subjects
Details
- Language :
- English
- ISSN :
- 1432-1335
- Volume :
- 142
- Issue :
- 9
- Database :
- MEDLINE
- Journal :
- Journal of cancer research and clinical oncology
- Publication Type :
- Academic Journal
- Accession number :
- 27424190
- Full Text :
- https://doi.org/10.1007/s00432-016-2205-5