Generation of telomeric G strand overhangs involves both G and C strand cleavage

被引:49
作者
Jacob, NK
Kirk, KE
Price, CM [1 ]
机构
[1] Univ Cincinnati, Coll Med, Dept Mol Genet Biochem & Microbiol, Cincinnati, OH 45267 USA
[2] Lake Forest Coll, Dept Biol, Lake Forest, IL 60045 USA
关键词
D O I
10.1016/S1097-2765(03)00131-X
中图分类号
Q5 [生物化学]; Q7 [分子生物学];
学科分类号
071010 ; 081704 ;
摘要
Processing of telomeric DNA is required to generate the 3' G strand overhangs necessary for capping chromosome ends. We have investigated the steps involved in telomere processing by examining G overhang structure in Tetrahymena cells that lack telomerase or have altered telomeric sequences. We show that overhangs are generated by two precise cleavage steps involving nucleases that are robust but lack sequence specificity. Our data suggest that a G overhang binding protein delineates the boundaries for G and C strand cleavage. We also show that telomerase is not the nuclease responsible for G strand cleavage, although telomerase depletion alters the precision of processing. This change in processing indicates that telomerase affects multiple transactions at the telomere and provides a physical footprint for the continued association of telomerase with the telomere after repeat addition is complete.
引用
收藏
页码:1021 / 1032
页数:12
相关论文
共 48 条
[1]  
[Anonymous], 2002, MOBILE DNA
[2]   FUNCTIONAL RECONSTITUTION OF WILD-TYPE AND MUTANT TETRAHYMENA TELOMERASE [J].
AUTEXIER, C ;
GREIDER, CW .
GENES & DEVELOPMENT, 1994, 8 (05) :563-575
[3]   Human Pot1 (Protection of telomeres) protein: Cytolocalization, gene structure, and alternative splicing [J].
Baumann, P ;
Podell, E ;
Cech, TR .
MOLECULAR AND CELLULAR BIOLOGY, 2002, 22 (22) :8079-8087
[4]   Pot1, the putative telomere end-binding protein in fission yeast and humans [J].
Baumann, P ;
Cech, TR .
SCIENCE, 2001, 292 (5519) :1171-1175
[5]   Mechanisms of chromosome-end protection [J].
Cervantes, RB ;
Lundblad, V .
CURRENT OPINION IN CELL BIOLOGY, 2002, 14 (03) :351-356
[6]   New ways not to make ends meet: telomerase, DNA damage proteins and heterochromatin [J].
Chan, SWL ;
Blackburn, EH .
ONCOGENE, 2002, 21 (04) :553-563
[7]   Ciliate telomerase biochemistry [J].
Collins, K .
ANNUAL REVIEW OF BIOCHEMISTRY, 1999, 68 :187-218
[8]   TETRAHYMENA TELOMERASE CATALYZES NUCLEOLYTIC CLEAVAGE AND NONPROCESSIVE ELONGATION [J].
COLLINS, K ;
GREIDER, CW .
GENES & DEVELOPMENT, 1993, 7 (7B) :1364-1376
[9]   The reverse transcriptase component of the Tetrahymena telomerase ribonucleoprotein complex [J].
Collins, K ;
Gandhi, L .
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 1998, 95 (15) :8485-8490
[10]   Genome downsizing during ciliate development: Nuclear Division of Labor through chromosome restructuring [J].
Coyne, RS ;
Chalker, DL ;
Yao, MC .
ANNUAL REVIEW OF GENETICS, 1996, 30 :557-578