Ribosomal shunting mediated by a translational enhancer element that base pairs to 18S rRNA

被引:45
作者
Chappell, Stephen A.
Dresios, John
Edelman, Gerald M.
Mauro, Vincent P.
机构
[1] Scripps Res Inst, Dept Neurobiol, La Jolla, CA 92037 USA
[2] Scripps Res Inst, Skaggs Inst Chem Biol, La Jolla, CA 92037 USA
关键词
mRNA; ribosome; translation; sequence complementarity; 5' leader;
D O I
10.1073/pnas.0603597103
中图分类号
O [数理科学和化学]; P [天文学、地球科学]; Q [生物科学]; N [自然科学总论];
学科分类号
07 ; 0710 ; 09 ;
摘要
In eukaryotes, 40S ribosomal subunits move from their recruitment site on the mRNA to the initiation codon by an as yet poorly understood process. One postulated mechanism involves ribosomal shunting, in which ribosomal subunits completely bypass regions of the 5' leader. For some mRNAs, shunting has been shown to require various mRNA elements, some of which are thought to base pair to 18S rRNA; however, the role of base pairing has not yet been tested directly. In earlier studies, we demonstrated that a short mRNA element in the 5' leader of the Gtx homeodomain mRNA functioned as a ribosomal recruitment site by base pairing to the 18S rRNA. Using a model system to assess translation in transfected cells, we now show that this intermolecular interaction also facilitates ribosomal shunting across two types of obstacles: an upstream AUG codon in excellent context or a stable hairpin structure. Highly efficient shunting occurred when multiple Gtx elements were present upstream of the obstacles, and a single Gtx element was present downstream. Shunting was less efficient, however, when the multiple Gtx elements were present only upstream of the obstacles. In addition, control experiments with mRNAs lacking the upstream elements showed that these results could not be attributed to recruitment by the single downstream element. Experiments in yeast in which the mRNA elements and 18S rRNA sequences were both mutated indicated that shunting required an intact complementary match. The data obtained by this model system provide direct evidence that ribosomal shunting can be mediated by mRNA-rRNA base pairing, a finding that may have general implications for mechanisms of ribosome movement.
引用
收藏
页码:9488 / 9493
页数:6
相关论文
共 27 条
[1]   A 9-nt segment of a cellular mRNA can function as an internal ribosome entry site (IRES) and when present in linked multiple copies greatly enhances IRES activity [J].
Chappell, SA ;
Edelman, GM ;
Mauro, VP .
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 2000, 97 (04) :1536-1541
[2]   Biochemical and functional analysis of a 9-nt RNA sequence that affects translation efficiency in eukaryotic cells [J].
Chappell, SA ;
Edelman, GM ;
Mauro, VP .
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 2004, 101 (26) :9590-9594
[3]   Endonucleolytic cleavage of eukaryotic mRNAs with stalls in translation elongation [J].
Doma, MK ;
Parker, R .
NATURE, 2006, 440 (7083) :561-564
[4]   An mRNA-rRNA base-pairing mechanism for translation initiation in eukaryotes [J].
Dresios, J ;
Chappell, SA ;
Zhou, W ;
Mauro, VP .
NATURE STRUCTURAL & MOLECULAR BIOLOGY, 2006, 13 (01) :30-34
[5]   Physical evidence for distinct mechanisms of translational control by upstream open reading frames [J].
Gaba, A ;
Wang, Z ;
Krishnamoorthy, T ;
Hinnebusch, AG ;
Sachs, MS .
EMBO JOURNAL, 2001, 20 (22) :6453-6463
[6]   Dicing and slicing - The core machinery of the RNA interference pathway [J].
Hammond, SM .
FEBS LETTERS, 2005, 579 (26) :5822-5829
[7]   HIV-2 genomic RNA contains a novel type of IRES located downstream of its initiation codon [J].
Herbreteau, CH ;
Weill, L ;
Décimo, D ;
Prévôt, D ;
Darlix, JL ;
Sargueil, B ;
Ohlmann, T .
NATURE STRUCTURAL & MOLECULAR BIOLOGY, 2005, 12 (11) :1001-1007
[8]   TRANSLATION OF THE 2ND GENE OF PEANUT CLUMP VIRUS-RNA-2 OCCURS BY LEAKY SCANNING IN-VITRO [J].
HERZOG, E ;
GUILLEY, H ;
FRITSCH, C .
VIROLOGY, 1995, 208 (01) :215-225
[9]  
HINNEBUSCH AG, 1993, TRANSLATIONAL REGULA, V2, P87
[10]  
Jackson RJ, 2000, COLD SPRING HARBOR M, V39, P127