title: Alternative 3'-end processing of long noncoding RNA initiates construction of nuclear paraspeckles.
abstract: Paraspeckles are unique subnuclear structures built around a specific long noncoding RNA, NEAT1, which is comprised of two isoforms produced by alternative 3'-end processing (NEAT1_1 and NEAT1_2). To address the precise molecular processes that lead to paraspeckle formation, we identified 35 paraspeckle proteins (PSPs), mainly by colocalization screening with a fluorescent protein-tagged full-length cDNA library. Most of the newly identified PSPs possessed various putative RNA-binding domains. Subsequent RNAi analyses identified seven essential PSPs for paraspeckle formation. One of the essential PSPs, HNRNPK, appeared to affect the production of the essential NEAT1_2 isoform by negatively regulating the 3'-end polyadenylation of the NEAT1_1 isoform. An in vitro 3'-end processing assay revealed that HNRNPK arrested binding of the CPSF6-NUDT21 (CFIm) complex in the vicinity of the alternative polyadenylation site of NEAT1_1. In vitro binding assays showed that HNRNPK competed with CPSF6 for binding to NUDT21, which was the underlying mechanism to arrest CFIm binding by HNRNPK. This HNRNPK function led to the preferential accumulation of NEAT1_2 and initiated paraspeckle construction with multiple PSPs.
authors.affiliation: Functional RNomics Team, Biomedicinal Information Research Center, National Institute of Advanced Industrial Science and Technology (AIST), Tokyo, Japan.
authors.forename: Takao
authors.initials: T
authors.lastname: Naganuma
authors.forename: Shinichi
authors.initials: S
authors.lastname: Nakagawa
authors.forename: Akie
authors.initials: A
authors.lastname: Tanigawa
authors.forename: Yasnory F
authors.initials: YF
authors.lastname: Sasaki
authors.forename: Naoki
authors.initials: N
authors.lastname: Goshima
authors.forename: Tetsuro
authors.initials: T
authors.lastname: Hirose
mesh_terms: D000818:Animals; D022003:Cell Nucleus Structures / Q000378:metabolism* / Q000648:ultrastructure; D039223:Cleavage And Polyadenylation Specificity Factor / Q000378:metabolism; D057809:HEK293 Cells; D006367:HeLa Cells; D034641:Heterogeneous-Nuclear Ribonucleoprotein K; D006801:Humans; D051379:Mice; D018345:Mice, Knockout; D046912:Multiprotein Complexes; D041681:NIH 3T3 Cells; D009687:Nuclear Proteins / Q000302:isolation & purification / Q000378:metabolism*; D026723:Polyadenylation / Q000235:genetics* / Q000502:physiology; D017434:Protein Structure, Tertiary; D059368:RNA Isoforms / Q000235:genetics* / Q000378:metabolism; D062085:RNA, Long Noncoding / Q000235:genetics* / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics* / Q000378:metabolism; D034741:RNA, Small Interfering / Q000235:genetics; D016601:RNA-Binding Proteins / Q000302:isolation & purification / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D012261:Ribonucleoproteins / Q000502:physiology*
chemical_list: C529056:CPSF6 protein, mouse; D039223:Cleavage And Polyadenylation Specificity Factor; C577277:HNRNPK protein, mouse; D034641:Heterogeneous-Nuclear Ribonucleoprotein K; D046912:Multiprotein Complexes; C577276:NEAT1 long non-coding RNA, human; C577275:NEAT1 long non-coding RNA, mouse; D009687:Nuclear Proteins; C529055:Nudt21 protein, mouse; D059368:RNA Isoforms; D062085:RNA, Long Noncoding; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D016601:RNA-Binding Proteins; D011993:Recombinant Fusion Proteins; D012261:Ribonucleoproteins; C072074:HNRNPK protein, human