title: Identification of cis- and trans-acting factors involved in the localization of MALAT-1 noncoding RNA to nuclear speckles.
abstract: MALAT-1 noncoding RNA is localized to nuclear speckles despite its mRNA-like characteristics. Here, we report the identification of several key factors that promote the localization of MALAT-1 to nuclear speckles and also provide evidence that MALAT-1 is involved in the regulation of gene expression. Heterokaryon assays revealed that MALAT-1 does not shuttle between the nucleus and cytoplasm. RNAi-mediated repression of the nuclear speckle proteins, RNPS1, SRm160, or IBP160, which are well-known mRNA processing factors, resulted in the diffusion of MALAT-1 to the nucleoplasm. We demonstrated that MALAT-1 contains two distinct elements directing transcripts to nuclear speckles, which were also capable of binding to RNPS1 in vitro. Depletion of MALAT-1 represses the expression of several genes. Taken together, our results suggest that RNPS1, SRm160, and IBP160 contribute to the localization of MALAT-1 to nuclear speckles, where MALAT-1 could be involved in regulating gene expression.
authors.affiliation: Radioisotope Center, The University of Tokyo, Bunkyo-ku, Tokyo 113-0032, Japan.
authors.forename: Ryu
authors.initials: R
authors.lastname: Miyagawa
authors.forename: Keiko
authors.initials: K
authors.lastname: Tano
authors.forename: Rie
authors.initials: R
authors.lastname: Mizuno
authors.forename: Yo
authors.initials: Y
authors.lastname: Nakamura
authors.forename: Kenichi
authors.initials: K
authors.lastname: Ijiri
authors.forename: Randeep
authors.initials: R
authors.lastname: Rakwal
authors.forename: Junko
authors.initials: J
authors.lastname: Shibato
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Masuo
authors.forename: Akila
authors.initials: A
authors.lastname: Mayeda
authors.forename: Tetsuro
authors.initials: T
authors.lastname: Hirose
authors.forename: Nobuyoshi
authors.initials: N
authors.lastname: Akimitsu
mesh_terms: D001483:Base Sequence; D002467:Cell Nucleus / Q000378:metabolism*; D017931:DNA Primers; D015536:Down-Regulation; D006367:HeLa Cells; D006801:Humans; D034622:RNA Interference; D062085:RNA, Long Noncoding; D022661:RNA, Untranslated / Q000235:genetics / Q000378:metabolism*
chemical_list: D017931:DNA Primers; C557041:MALAT1 long non-coding RNA, human; D062085:RNA, Long Noncoding; D022661:RNA, Untranslated