Transposable elements are DNA sequences that can move (i.e., transpose) to different genomic locations and they are present in the genomes of virtually all organisms studied. There are two general classes of transposable elements: transposons and retrotransposons. Retrotransposons mobilize via an RNA intermediate and transpose by a replicative mechanism termed retrotransposition. Long Interspersed Nuclear Elements (LINES or L1s) are the most abundant retrotransposons in the human genome and they comprise approximately 15 percent of DNA. An estimated 30-60 human L1 elements are retrotransposition-competent, and both germ line and somatic L1 retrotransposition events have caused disease. It also is hypothesized that the proteins encoded by retrotransposition-competent L1s mobilize certain SINES (e.g., Alu elements) and processed pseudogenes, which comprise another 10 percent of human DNA. Alu retrotransposition also is mutagenic and eleven de novo Alu insertions have been found to cause different diseases in the past seven years. Thus, either directly or through the promiscuous mobilization of cellular RNAs, L1s are potent mutagens in the human genome. Despite the mutagenic potential of L1s, studies concerning the mechanistic aspects of L1 retrotransposition are in their infancy. A recently developed assay to monitor L1 retrotransposition in cultured human cells and molecular biological and biochemical approaches will be used to determine the mechanism of L1 retrotransposition at the molecular level. Specifically, experiments will be performed to: 1) identify cis-acting sequences in L1 RNA and function al domains in the L1-encoded proteins required for retrotransposition; 2) identify factors that govern template choice by the L1-encoded proteins; and 3) identify in vivo intermediates in the L1 retrotransposition pathway. The long-term goal of this project is to gain a fundamental understanding of how L1 retrotransposition contributes to human disease and genetic diversity. A fundamental mechanistic understanding of L1 retrotransposition also will allow the practical development of engineered L1s as a transposon mutagen for the mouse genome and as a potential gene delivery vehicle for human studies.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM060518-05
Application #
6644824
Study Section
Mammalian Genetics Study Section (MGN)
Program Officer
Rhoades, Marcus M
Project Start
1999-09-30
Project End
2004-12-31
Budget Start
2003-09-01
Budget End
2004-12-31
Support Year
5
Fiscal Year
2003
Total Cost
$283,072
Indirect Cost
Name
University of Michigan Ann Arbor
Department
Genetics
Type
Schools of Medicine
DUNS #
073133571
City
Ann Arbor
State
MI
Country
United States
Zip Code
48109
Kopera, Huira C; Flasch, Diane A; Nakamura, Mitsuhiro et al. (2016) LEAP: L1 Element Amplification Protocol. Methods Mol Biol 1400:339-55
Kopera, Huira C; Larson, Peter A; Moldovan, John B et al. (2016) LINE-1 Cultured Cell Retrotransposition Assay. Methods Mol Biol 1400:139-56
Wylie, Annika; Jones, Amanda E; D'Brot, Alejandro et al. (2016) p53 genes function to restrain mobile elements. Genes Dev 30:64-77
Moldovan, John B; Moran, John V (2015) The Zinc-Finger Antiviral Protein ZAP Inhibits LINE and Alu Retrotransposition. PLoS Genet 11:e1005121
Richardson, Sandra R; Doucet, Aurélien J; Kopera, Huira C et al. (2015) The Influence of LINE-1 and SINE Retrotransposons on Mammalian Genomes. Microbiol Spectr 3:MDNA3-0061-2014
Doucet, Aurélien J; Wilusz, Jeremy E; Miyoshi, Tomoichiro et al. (2015) A 3' Poly(A) Tract Is Required for LINE-1 Retrotransposition. Mol Cell 60:728-741
Richardson, Sandra R; Narvaiza, Iñigo; Planegger, Randy A et al. (2014) APOBEC3A deaminates transiently exposed single-strand DNA during LINE-1 retrotransposition. Elife 3:e02008
Zhang, Ao; Dong, Beihua; Doucet, Aurélien J et al. (2014) RNase L restricts the mobility of engineered retrotransposons in cultured human cells. Nucleic Acids Res 42:3803-20
Singh, Parmit Kumar; Bourque, Guillaume; Craig, Nancy L et al. (2014) Mobile genetic elements and genome evolution 2014. Mob DNA 5:26
Macfarlane, Catriona M; Collier, Pamela; Rahbari, Raheleh et al. (2013) Transduction-specific ATLAS reveals a cohort of highly active L1 retrotransposons in human populations. Hum Mutat 34:974-85

Showing the most recent 10 out of 46 publications