title: Interleukin-32α modulates promyelocytic leukemia zinc finger gene activity by inhibiting protein kinase Cɛ-dependent sumoylation.
abstract: Interleukin-32 (IL-32) is a proinflammatory cytokine. However, there is growing evidence that IL-32 also plays a mediatory role intracellularly. In this study, we present evidence that IL-32α modifies and inhibits promyelocytic leukemia zinc finger (PLZF), a sequence-specific transcriptional regulator that regulates the expression of a subset of interferon (IFN)-stimulated genes (ISGs). We screened IL-32α-interacting proteins in a human spleen cDNA library using the yeast two-hybrid assay, and investigated the functional relevance of the interaction between IL-32α and PLZF. We demonstrated that IL-32α interacts with protein kinase C (PKC)δ and PKCɛ in a phorbol 12-myristate 13-acetate (PMA) dependent way, and that PKCɛ regulates the interaction of IL-32α with PLZF. We verified the involvement of PKCɛ in the interaction between these proteins by using various PKC inhibitors. PLZF is known to be modified by small ubiquitin-like modifier (SUMO)-1, but it is unclear whether SUMO-2 conjugation of PLZF occurs. We showed that IL-32α inhibited SUMO-2-conjugation of PLZF. Further, we demonstrated that sumoylated PLZF decreased when IL-32α was co-expressed. PKCɛ affected the sumoylation of PLZF only in the presence of IL-32α because PKC inhibitor treatment did not reduce PLZF sumoylation in the absence of IL-32α. We finally investigated whether IL-32α-mediated inhibition of PLZF sumoylation affected the transcriptional activity of PLZF, and demonstrated that the inhibition of sumoylation of PLZF by IL-32α down-regulated ISGs induced by PLZF. Together, our data suggest that IL-32α associates with PLZF and PKCɛ, and then inhibits PLZF sumoylation, resulting in suppression of the transcriptional activity of PLZF.
authors.affiliation: Department of Bioscience and Biotechnology, Bio/Molecular Informatics Center, Konkuk University, Seoul 143-701, Republic of Korea.
authors.forename: Yun Sun
authors.initials: YS
authors.lastname: Park
authors.affiliation: Department of Bioscience and Biotechnology, Bio/Molecular Informatics Center, Konkuk University, Seoul 143-701, Republic of Korea.
authors.forename: Jeong-Woo
authors.initials: JW
authors.lastname: Kang
authors.affiliation: Department of Bioscience and Biotechnology, Bio/Molecular Informatics Center, Konkuk University, Seoul 143-701, Republic of Korea.
authors.forename: Dong Hun
authors.initials: DH
authors.lastname: Lee
authors.affiliation: Department of Bioscience and Biotechnology, Bio/Molecular Informatics Center, Konkuk University, Seoul 143-701, Republic of Korea.
authors.forename: Man Sub
authors.initials: MS
authors.lastname: Kim
authors.affiliation: Department of Bioscience and Biotechnology, Bio/Molecular Informatics Center, Konkuk University, Seoul 143-701, Republic of Korea.
authors.forename: Yesol
authors.initials: Y
authors.lastname: Bak
authors.affiliation: Research Center for Women's Disease, Department of Life Systems, Sookmyung Women's University, Seoul 140-742, Republic of Korea.
authors.forename: Young
authors.initials: Y
authors.lastname: Yang
authors.affiliation: Medical Genomics Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon 305-806, Republic of Korea.
authors.forename: Hee-Gu
authors.initials: HG
authors.lastname: Lee
authors.affiliation: College of Pharmacy and Medical Research Center, Chungbuk National University, Cheongju 361-463, Republic of Korea.
authors.forename: Jintae
authors.initials: J
authors.lastname: Hong
authors.affiliation: Department of Bioscience and Biotechnology, Bio/Molecular Informatics Center, Konkuk University, Seoul 143-701, Republic of Korea. Electronic address: ydy4218@konkuk.ac.kr.
authors.forename: Do-Young
authors.initials: DY
authors.lastname: Yoon
mesh_terms: D015153:Blotting, Western; D045744:Cell Line, Tumor; D004791:Enzyme Inhibitors / Q000494:pharmacology; D015870:Gene Expression / Q000187:drug effects; D057809:HEK293 Cells; D006801:Humans; D047468:Immunoprecipitation; D007211:Indoles / Q000494:pharmacology; D007372:Interferons / Q000494:pharmacology; D007378:Interleukins / Q000235:genetics / Q000378:metabolism*; D051741:Kruppel-Like Transcription Factors / Q000235:genetics / Q000378:metabolism*; D000075722:Promyelocytic Leukemia Zinc Finger Protein; D011485:Protein Binding / Q000187:drug effects; D051744:Protein Kinase C-epsilon / Q000037:antagonists & inhibitors / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D025841:Small Ubiquitin-Related Modifier Proteins / Q000235:genetics / Q000378:metabolism; D058207:Sumoylation / Q000187:drug effects; D020798:Two-Hybrid System Techniques; D016335:Zinc Fingers
chemical_list: D004791:Enzyme Inhibitors; C496971:IL32 protein, human; D007211:Indoles; D007378:Interleukins; D051741:Kruppel-Like Transcription Factors; D000075722:Promyelocytic Leukemia Zinc Finger Protein; C117909:SUMO2 protein, human; D025841:Small Ubiquitin-Related Modifier Proteins; C092037:ZBTB16 protein, human; D007372:Interferons; D051744:Protein Kinase C-epsilon; C064758:Ro 31-8220
keywords: Interleukin 32α; Promyelocytic leukemia zinc finger protein; Small ubiquitin-like modifier-2