MTV, an ssDNA Protecting Complex Essential for Transposon-Based Telomere Maintenance in Drosophila.
Multiple complexes protect telomeres. In telomerase-maintained organisms, Shelterin related complexes occupy the duplex region while the CST and Tpp1-Pot1 complexes bind the single stranded overhang of telomeres. Drosophila uses a transposon-based mechanism for end protection. We showed that the HOAP-HipHop complex occupies the duplex region. Whether an ssDNA-binding complex exists is not known. Here we discover a novel protein, Tea, that is specifically enriched at telomeres to prevent telomere fusion. We also identify a complex consisting of Tea and two known capping proteins, Ver and Moi. The Moi-Tea-Ver (MTV) complex purified in vitro binds and protects ssDNA in a sequence-independent manner. Tea recruits Ver and Moi to telomeres, and point mutations disrupting MTV interaction in vitro result in telomere uncapping, consistent with these proteins functioning as a complex in vivo. MTV thus shares functional similarities with CST or TPP1-POT1 in protecting ssDNA, highlighting a conserved feature in end protecting mechanisms.
State Key Laboratory of Bio-control, Institute of Entomology, School of Life Sciences, Sun Yat-sen University, Guangzhou, China.|Laboratory of Biochemistry and Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, United States of America.
Yi
Y
Zhang
Laboratory of Biochemistry and Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, United States of America.
Liang
L
Zhang
Laboratory of Biochemistry and Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, United States of America.
Xiaona
http://orcid.org/0000-0003-2665-1197
X
Tang
Laboratory of Biochemistry and Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, United States of America.
Shilpa R
SR
Bhardwaj
State Key Laboratory of Bio-control, Institute of Entomology, School of Life Sciences, Sun Yat-sen University, Guangzhou, China.
Jingyun
J
Ji
State Key Laboratory of Bio-control, Institute of Entomology, School of Life Sciences, Sun Yat-sen University, Guangzhou, China.|Laboratory of Biochemistry and Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, United States of America.
Yikang S
YS
Rong
D000818:Animals; D002352:Carrier Proteins / Q000235:genetics; D002868:Chromosomal Proteins, Non-Histone / Q000235:genetics*; D004251:DNA Transposable Elements / Q000235:genetics; D004277:DNA, Single-Stranded / Q000235:genetics*; D029721:Drosophila Proteins / Q000235:genetics*; D004331:Drosophila melanogaster / Q000235:genetics; D009414:Nerve Growth Factors / Q000235:genetics*; D017354:Point Mutation / Q000235:genetics; D011485:Protein Binding / Q000235:genetics; D017346:Protein Serine-Threonine Kinases / Q000235:genetics; D019098:Telomerase / Q000235:genetics; D016615:Telomere / Q000235:genetics; D059505:Telomere Homeostasis / Q000235:genetics*
D002352:Carrier Proteins; D002868:Chromosomal Proteins, Non-Histone; D004251:DNA Transposable Elements; D004277:DNA, Single-Stranded; D029721:Drosophila Proteins; D009414:Nerve Growth Factors; C000618223:Tea protein, Drosophila; C539342:moi protein, Drosophila; C503623:pot protein, Drosophila; C412165:sbb protein, Drosophila; D017346:Protein Serine-Threonine Kinases; D019098:Telomerase