title: Aly and THO are required for assembly of the human TREX complex and association of TREX components with the spliced mRNA.
abstract: The mRNA export complex TREX (TREX) is known to contain Aly, UAP56, Tex1 and the THO complex, among which UAP56 is required for TREX assembly. Here, we systematically investigated the role of each human TREX component in TREX assembly and its association with the mRNA. We found that Tex1 is essentially a subunit of the THO complex. Aly, THO and UAP56 are all required for assembly of TREX, in which Aly directly interacts with THO subunits Thoc2 and Thoc5. Both Aly and THO function in linking UAP56 to the cap-binding protein CBP80. Interestingly, association of UAP56 with the spliced mRNA, but not with the pre-mRNA, requires Aly and THO. Unexpectedly, we found that Aly and THO require each other to associate with the spliced mRNA. Consistent with these biochemical results, similar to Aly and UAP56, THO plays critical roles in mRNA export. Together, we propose that Aly, THO and UAP56 form a highly integrated unit to associate with the spliced mRNA and function in mRNA export.
authors.affiliation: State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China.
authors.forename: Binkai
authors.initials: B
authors.lastname: Chi
authors.forename: Qingliang
authors.initials: Q
authors.lastname: Wang
authors.forename: Guifen
authors.initials: G
authors.lastname: Wu
authors.forename: Ming
authors.initials: M
authors.lastname: Tan
authors.forename: Lantian
authors.initials: L
authors.lastname: Wang
authors.forename: Min
authors.initials: M
authors.lastname: Shi
authors.forename: Xingya
authors.initials: X
authors.lastname: Chang
authors.forename: Hong
authors.initials: H
authors.lastname: Cheng
mesh_terms: D053487:DEAD-box RNA Helicases / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D039502:Nuclear Cap-Binding Protein Complex / Q000378:metabolism; D009687:Nuclear Proteins / Q000378:metabolism* / Q000502:physiology; D021122:Protein Subunits / Q000378:metabolism; D012322:RNA Precursors / Q000378:metabolism; D012326:RNA Splicing; D034443:RNA Transport; D012333:RNA, Messenger / Q000378:metabolism*; D016601:RNA-Binding Proteins / Q000378:metabolism* / Q000502:physiology; D014157:Transcription Factors / Q000378:metabolism* / Q000502:physiology
chemical_list: C105242:ALYREF protein, human; D039502:Nuclear Cap-Binding Protein Complex; D009687:Nuclear Proteins; D021122:Protein Subunits; D012322:RNA Precursors; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; C530378:THOC5 protein, human; C579431:Tex1 protein, human; C579432:Thoc2 protein, human; D014157:Transcription Factors; C487886:DDX39B protein, human; D053487:DEAD-box RNA Helicases