title: Structural features important for the U12 snRNA binding and minor spliceosome assembly of Arabidopsis U11/U12-small nuclear ribonucleoproteins.
abstract: Although seven proteins unique to U12 intron-specific minor spliceosomes, denoted as U11/U12-65K, -59K, -48K, -35K, -31K, -25K, and -20K, have been identified in humans and the roles of some of them have been demonstrated, the functional role of most of these proteins in plants is not understood. A recent study demonstrated that Arabidopsis U11/U12-65K is essential for U12 intron splicing and normal plant development. However, the structural features and sequence motifs important for 65 K binding to U12 snRNA and other spliceosomal proteins remain unclear. Here, we demonstrated by domain-deletion analysis that the C-terminal region of the 65 K protein bound specifically to the stem-loop III of U12 snRNA, whereas the N-terminal region of the 65 K protein was responsible for interacting with the 59 K protein. Analysis of the interactions between each snRNP protein using yeast two-hybrid analysis and in planta bimolecular fluorescence complementation and luciferase complementation imaging assays demonstrated that the core interactions among the 65 K, 59 K, and 48 K proteins were conserved between plants and animals, and multiple interactions were observed among the U11/U12-snRNP proteins. Taken together, these results reveal that U11/U12-65K is an indispensible component of the minor spliceosome complex by binding to both U11/U12-59K and U12 snRNA, and that multiple interactions among the U11/U12-snRNP proteins are necessary for minor spliceosome assembly.
authors.affiliation: a Department of Plant Biotechnology , College of Agriculture and Life Sciences, Chonnam National University , Yongbong-dong, Buk-gu, Gwangju , South Korea.
authors.forename: Su Jung
authors.initials: SJ
authors.lastname: Park
authors.affiliation: a Department of Plant Biotechnology , College of Agriculture and Life Sciences, Chonnam National University , Yongbong-dong, Buk-gu, Gwangju , South Korea.
authors.forename: Hyun Ju
authors.initials: HJ
authors.lastname: Jung
authors.affiliation: a Department of Plant Biotechnology , College of Agriculture and Life Sciences, Chonnam National University , Yongbong-dong, Buk-gu, Gwangju , South Korea.
authors.forename: Sy
authors.initials: S
authors.lastname: Nguyen Dinh
authors.affiliation: a Department of Plant Biotechnology , College of Agriculture and Life Sciences, Chonnam National University , Yongbong-dong, Buk-gu, Gwangju , South Korea.
authors.forename: Hunseung
authors.initials: H
authors.lastname: Kang
mesh_terms: D017360:Arabidopsis / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D018749:RNA, Plant / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D012342:RNA, Small Nuclear / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D017411:Ribonucleoproteins, Small Nuclear / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D017381:Spliceosomes / Q000737:chemistry / Q000235:genetics / Q000378:metabolism
chemical_list: D029681:Arabidopsis Proteins; D018749:RNA, Plant; D012342:RNA, Small Nuclear; D017411:Ribonucleoproteins, Small Nuclear; C552126:U11-U12 small nuclear ribonucleoprotein; C096986:U12 small nuclear RNA
keywords: Arabidopsis; U11/U12-65K; U12 intron; minor spliceosome; spliceosome assembly; splicing