title: Selective nuclear export mechanism of small RNAs.
abstract: The timely nuclear-cytoplasmic translocation of proteins and RNAs by importins and exportins is important for controlling biological processes. Since the 2004 publication of the first exportin structure, Cse1p, the X-ray structures of exportin-5 complexed with pre-microRNA, exportin-t complexed with tRNA, and three CRM1-related structures have revealed the binding mechanism involved in specific cargo recognition. Pre-microRNA and tRNA have conserved 3' 2-4-nucleotide overhang motifs and similar short double-stranded regions. Exportin-5 and exportin-t bind a conserved 3' overhang strongly, and they weakly enclose the short double-stranded stems, each in a different manner. The structures of the nuclear export complexes of small double-stranded RNAs, pre-microRNAs, and tRNAs provide information about the specificities of the two exportins in the context of transcription and translation control.
authors.affiliation: College of Pharmacy, Chungbuk National University, Heungduk-gu, Cheongju, Chungbuk, Republic of Korea. sjlee@chungbuk.ac.kr
authors.forename: Soo Jae
authors.initials: SJ
authors.lastname: Lee
authors.forename: Chimari
authors.initials: C
authors.lastname: Jiko
authors.forename: Eiki
authors.initials: E
authors.lastname: Yamashita
authors.forename: Tomitake
authors.initials: T
authors.lastname: Tsukihara
mesh_terms: D021581:Active Transport, Cell Nucleus; D000818:Animals; D006801:Humans; D035683:MicroRNAs / Q000737:chemistry / Q000378:metabolism*; D011485:Protein Binding; D012330:RNA, Double-Stranded / Q000737:chemistry / Q000378:metabolism*; D012343:RNA, Transfer / Q000737:chemistry / Q000378:metabolism*
chemical_list: D035683:MicroRNAs; D012330:RNA, Double-Stranded; D012343:RNA, Transfer