TAILIEUCHUNG - Báo cáo khoa học: Human telomeric G-quadruplex: structures of DNA and RNA sequences

The innate immune response of insects includes induced expression of genes encoding a variety of antimicrobial peptides. The signaling pathways that stimulate this gene expression have been well characterized by genetic analy-sis in Drosophila melanogaster, but are not well understood in most other insect species. | ỊFEBS Journal MINIREVIEW Human telomeric G-quadruplex structures of DNA and RNA sequences Anh Tuân Phan Schoolof Physical MathematicalSciences Nanyang TechnologicalUniversity Singapore Keywords DNA G-quadruplex G-quadruplex structure G-quadruplex topology G-tetrad G-tetrad core grooves in G-quadruplexes human telomere loops in G-quadruplexes RNA Correspondence A. T. Phan Division of Physics Applied Physics Schoolof Physical Mathematical Sciences Nanyang TechnologicalUniversity Singapore 637371 Fax 65 6795 7981 Tel 65 6514 1915 E-mail phantuan@ Received 25 June 2009 revised 14 September 2009 accepted 6 October 2009 doi Telomeres play an important role in cellular aging and cancer. Human telomeric DNA and RNA G-rich sequences are capable of forming a four-stranded structure known as the G-quadruplex. Such a structure might be important for telomere biology and a good target for drug design. This minireview describes the structural diversity or conservation of DNA and RNA human telomeric G-quadruplexes discusses structural views on targeting these G-quadruplexes and presents some future challenges for structural studies. Introduction Human telomeric DNA contains thousands of tandem repeats of the G-rich GGGTTA n sequence 1 with a 3 -end overhang of 100-200 nucleotides 2 . Telomeres can be transcribed by DNA-dependent RNA polymerase II and telomeric-repeat-containing RNA molecules ranging from 100 to 9000 nucleotides have been detected in nuclear fractions 3-5 . Under physiological ionic conditions human telomeric DNA and RNA G-rich sequences are capable of forming a four-stranded helical structure known as the G-quadruplex 6-14 based on the stacking of multiple G G G G tetrads or G-tetrads 15 Fig. 1A . Such a structure might be important for telomere biology 5-14 16-19 and a good target for drug design 5-14 19-21 . G-quadruplex structures formed by various G-rich sequences have been reviewed previously 6-14 . This minireview

TỪ KHÓA LIÊN QUAN
Đã phát hiện trình chặn quảng cáo AdBlock
Trang web này phụ thuộc vào doanh thu từ số lần hiển thị quảng cáo để tồn tại. Vui lòng tắt trình chặn quảng cáo của bạn hoặc tạm dừng tính năng chặn quảng cáo cho trang web này.