title: PCGF2 negatively regulates arsenic trioxide-induced PML-RARA protein degradation via UBE2I inhibition in NB4 cells.
abstract: Arsenic trioxide (ATO) is a therapeutic agent for acute promyelocytic leukemia (APL) which induces PML-RARA protein degradation via enhanced UBE2I-mediated sumoylation. PCGF2, a Polycomb group protein, has been suggested as an anti-SUMO E3 protein by inhibiting the sumoylation of UBE2I substrates, HSF2 and RANGAP1, via direct interaction. Thus, we hypothesized that PCGF2 might play a role in ATO-induced PML-RARA degradation by interacting with UBE2I. PCGF2 protein was down-regulated upon ATO treatment in human APL cell line, NB4. Knockdown of PCGF2 in NB4 cells, in the absence of ATO treatment, was sufficient to induce sumoylation-, ubiquitylation- and PML nuclear body-mediated degradation of PML-RARA protein. Moreover, overexpression of PCGF2 protected ATO-mediated degradation of ectopic and endogenous PML-RARA in 293T and NB4 cells, respectively. In 293T cells, UBE2I-mediated PML-RARA degradation was reduced upon PCGF2 co-expression. In addition, UBE2I-mediated sumoylation of PML-RARA was reduced upon PCGF2 co-expression and PCGF2-UBE2I interaction was confirmed by co-immunoprecipitation. Likewise, endogenous PCGF2-UBE2I interaction was detected by co-immunoprecipitation and immunofluorescence assays in NB4 cells. Intriguingly, upon ATO-treatment, such interaction was disrupted and UBE2I was co-immunoprecipitated or co-localized with its SUMO substrate, PML-RARA. Taken together, our results suggested a novel role of PCGF2 in ATO-mediated degradation of PML-RARA that PCGF2 might act as a negative regulator of UBE2I via direct interaction.
authors.affiliation: Hanyang Biomedical Research Institute, Hanyang University, 222 Wangsimni-ro, Seongdong-gu, Seoul 04763, Republic of Korea; Department of Biomedical Science, Graduate School of Biomedical Science and Bioengineering, 222 Wangsimni-ro, Seongdong-gu, Seoul 04763, Republic of Korea.
authors.forename: Sungsin
authors.initials: S
authors.lastname: Jo
authors.affiliation: Hanyang Biomedical Research Institute, Hanyang University, 222 Wangsimni-ro, Seongdong-gu, Seoul 04763, Republic of Korea; Department of Biomedical Science, Graduate School of Biomedical Science and Bioengineering, 222 Wangsimni-ro, Seongdong-gu, Seoul 04763, Republic of Korea.
authors.forename: Young Lim
authors.initials: YL
authors.lastname: Lee
authors.affiliation: Hanyang Biomedical Research Institute, Hanyang University, 222 Wangsimni-ro, Seongdong-gu, Seoul 04763, Republic of Korea; Department of Biomedical Laboratory Science, College of Health Science, Yonsei University, 1 Yongseidae-gil, Wonju, Gangwon-do 26493, Republic of Korea.
authors.forename: Sojin
authors.initials: S
authors.lastname: Kim
authors.affiliation: Hanyang Biomedical Research Institute, Hanyang University, 222 Wangsimni-ro, Seongdong-gu, Seoul 04763, Republic of Korea; Department of Biomedical Science, Graduate School, Hanyang University, 222 Wangsimni-ro, Seongdong-gu, Seoul 04763, Republic of Korea.
authors.forename: Hongki
authors.initials: H
authors.lastname: Lee
authors.affiliation: Hanyang Biomedical Research Institute, Hanyang University, 222 Wangsimni-ro, Seongdong-gu, Seoul 04763, Republic of Korea; Department of Pathology, College of Medicine, Hanyang University, 222 Wangsimni-ro, Seongdong-gu, Seoul 04763, Republic of Korea. Electronic address: hc2n@hanyang.ac.kr.
authors.forename: Heekyoung
authors.initials: H
authors.lastname: Chung
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology*; D000077237:Arsenic Trioxide; D001152:Arsenicals / Q000494:pharmacology*; D045744:Cell Line, Tumor; D005455:Fluorescent Antibody Technique; D015971:Gene Expression Regulation, Enzymologic; D015972:Gene Expression Regulation, Neoplastic; D057809:HEK293 Cells; D006801:Humans; D047468:Immunoprecipitation; D015473:Leukemia, Promyelocytic, Acute / Q000188:drug therapy* / Q000201:enzymology / Q000235:genetics / Q000473:pathology; D015514:Oncogene Proteins, Fusion / Q000235:genetics / Q000378:metabolism*; D010087:Oxides / Q000494:pharmacology*; D063150:Polycomb Repressive Complex 1 / Q000235:genetics / Q000378:metabolism*; D011485:Protein Binding; D059748:Proteolysis; D034622:RNA Interference; D015398:Signal Transduction / Q000187:drug effects; D058207:Sumoylation; D013997:Time Factors; D014162:Transfection; D044763:Ubiquitin-Conjugating Enzymes / Q000235:genetics / Q000378:metabolism*; D054875:Ubiquitination; D000098843:Ubiquitin-Conjugating Enzyme UBC9
chemical_list: D000970:Antineoplastic Agents; D001152:Arsenicals; D015514:Oncogene Proteins, Fusion; D010087:Oxides; C489348:PCGF2 protein, human; C093476:promyelocytic leukemia-retinoic acid receptor alpha fusion oncoprotein; D044763:Ubiquitin-Conjugating Enzymes; D063150:Polycomb Repressive Complex 1; D000098843:Ubiquitin-Conjugating Enzyme UBC9; D000077237:Arsenic Trioxide
keywords: Arsenic trioxide; PCGF2; PML-RARA; Protein degradation; Sumoylation; UBE2I