ISWI ATP-dependent remodeling of nucleoplasmic u-speckles in the brain of Drosophila melanogaster  

作　　者：Luca Lo Piccolo Andrea Attardi Rosa Bonaccorso Lorenzo Li Greci Giorgio Giurato Antonia Maria Rita Ingrassia Maria Cristina Onorati 

机构地区：[1]STEBICEF Department, University of Palermo [2]Kyoto Institute of Technology [3]Neuroimmunology Unit of San Raffaele Hospital [4]Turku Center for Biotechnology, University of Turku [5]Genomix4Life Srl, University of Salerno, Baronissi Campus

出　　处：《Journal of Genetics and Genomics》2017年第2期85-94,共10页遗传学报（英文版）

基　　金：supported by an Associazione Italiana Ricerca sul Cancro (AIRC) (MFAG-12779) fellowship;supported by My First Airc Grant (MFAG) number 12779 from AIRC to M.C.O

摘　　要：Heterogeneous nuclear ribonucleoproteins（hn RNPs） belong to the RNA-binding proteins family. They are involved in processing heterogeneous nuclear RNAs（hn RNAs） into mature m RNAs. These proteins participate in every step of m RNA cycle, such as m RNA export, localization, translation, stability and alternative splicing. At least 14 major hn RNPs, which have structural and functional homologues in mammals, are expressed in Drosophila melanogaster. Until now, six of these hn RNPs are known to be nucleus-localized and associated with the long non-coding RNA（lnc RNA） heat shock responsive u（hsru）in the omega speckle compartments（u-speckles）. The chromatin remodeler ISWI is the catalytic subunit of several ATP-dependent chromatin-remodeling complexes, and it is an essential factor for organization of u-speckles. Indeed, in ISWI null mutant, severe defects in u-speckles structure are detectable. Here, we clarify the role of ISWI in the hn RNPs-hsru interaction. Moreover, we describe how ISWI by its remodeling activity, controls hsru and hn RNPs engagement in u-speckles. Finally, we demonstrate that the sequestration of hn RNPs in u-speckles nuclear compartment is a fundamental event in gene expression control and represents a key step in the regulation of several pathways.Heterogeneous nuclear ribonucleoproteins（hn RNPs） belong to the RNA-binding proteins family. They are involved in processing heterogeneous nuclear RNAs（hn RNAs） into mature m RNAs. These proteins participate in every step of m RNA cycle, such as m RNA export, localization, translation, stability and alternative splicing. At least 14 major hn RNPs, which have structural and functional homologues in mammals, are expressed in Drosophila melanogaster. Until now, six of these hn RNPs are known to be nucleus-localized and associated with the long non-coding RNA（lnc RNA） heat shock responsive u（hsru）in the omega speckle compartments（u-speckles）. The chromatin remodeler ISWI is the catalytic subunit of several ATP-dependent chromatin-remodeling complexes, and it is an essential factor for organization of u-speckles. Indeed, in ISWI null mutant, severe defects in u-speckles structure are detectable. Here, we clarify the role of ISWI in the hn RNPs-hsru interaction. Moreover, we describe how ISWI by its remodeling activity, controls hsru and hn RNPs engagement in u-speckles. Finally, we demonstrate that the sequestration of hn RNPs in u-speckles nuclear compartment is a fundamental event in gene expression control and represents a key step in the regulation of several pathways.

关 键 词：Omega speckles hnRNPs lncRNA Nuclear body Chromatin remodelers 

分 类 号：Q78[生物学—分子生物学]