Insertion sequence IS10, the active transposable element of transposon Tn10, is one of the best characterized mobile genetic elements. Studies on IS10 have revealed many aspects of gene expression that are of general importance to molecular biologists, including antisense RNA control, the focus of much of the research efforts described here. The domains of the antisense RNA that determine its unusual stability and its efficient pairing to the transposase mRNA are now known, a detailed model for the pairing reaction, which differs from other well-defined cases, has been proposed, and it is now known that this antisense RNA works by inhibiting ribosome binding and facilitating mRNA decay. In the midst of these studies, two other important post-transcriptional aspects of IS10 gene expression have been revealed. Both mechanisms involve intramolecular structures in the transposase mRNA. One is a short-range RNA/RNA interaction that prevents translation of RNAs initiated outside the IS10 element. The second is a long-range RNA/RNA interaction that restricts antisense binding and, probably, ribosome binding, to nascent mRNAs. In general, translational control of gene expression involves sequences and structures in RNA, as well as regulatory functions (RNA, protein or otherwise) that bind to and alter these sequences and structures or alter the integrity of the RNA itself. Many of these features remain ill-defined. Indeed, there remain a number of important questions concerning IS10 translational control. In the work proposed here, a genetic and biochemical assault will be mounted on issues of importance to antisense pairing and the short and long-range interactions in the transposase mRNA. Focus will be on the general question of how RNA sequences, present on the same or on different molecules, interact to form biologically relevant structures. Emphasis will be on the pathway, speed, stability and modulation of structure formation.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM035322-09
Application #
2177848
Study Section
Microbial Physiology and Genetics Subcommittee 2 (MBC)
Project Start
1985-07-01
Project End
1995-06-30
Budget Start
1993-07-01
Budget End
1995-06-30
Support Year
9
Fiscal Year
1993
Total Cost
Indirect Cost
Name
University of California Los Angeles
Department
Microbiology/Immun/Virology
Type
Schools of Arts and Sciences
DUNS #
119132785
City
Los Angeles
State
CA
Country
United States
Zip Code
90095
Pepe, C M; Suzuki, C; Laurie, C et al. (1997) Regulation of the ""tetCD"" genes of transposon Tn10. J Mol Biol 270:14-25
Sussman, J K; Simons, E L; Simons, R W (1996) Escherichia coli translation initiation factor 3 discriminates the initiation codon in vivo. Mol Microbiol 21:347-60
Ma, C K; Kolesnikow, T; Rayner, J C et al. (1994) Control of translation by mRNA secondary structure: the importance of the kinetics of structure formation. Mol Microbiol 14:1033-47
Pepe, C M; Maslesa-Galic, S; Simons, R W (1994) Decay of the IS10 antisense RNA by 3' exoribonucleases: evidence that RNase II stabilizes RNA-OUT against PNPase attack. Mol Microbiol 13:1133-42
Sussman, J K; Masada-Pepe, C; Simons, E L et al. (1990) Vectors for constructing kan gene fusions: direct selection of mutations affecting IS10 gene expression. Gene 90:135-40
Miller, W G; Simons, R W (1990) DNA from diverse sources manifests cryptic low-level transcription in Escherichia coli. Mol Microbiol 4:881-93
Case, C C; Simons, E L; Simons, R W (1990) The IS10 transposase mRNA is destabilized during antisense RNA control. EMBO J 9:1259-66
Ma, C; Simons, R W (1990) The IS10 antisense RNA blocks ribosome binding at the transposase translation initiation site. EMBO J 9:1267-74
Case, C C; Roels, S M; Gonzalez, J E et al. (1988) Analysis of the promoters and transcripts involved in IS10 anti-sense RNA control. Gene 72:219-36