title: TTAGG-repeat telomeres and characterization of telomerase in the beet armyworm, Spodoptera exigua (Lepidoptera: Noctuidae).
abstract: Telomeres are maintained usually by telomerase, a specialized reverse transcriptase that adds this sequence to chromosome ends. In this study, telomerase activity was detected in the in different somatic tissues, such as midgut and fat bodies, by the telomeric repeat amplification protocol (TRAP) in Spodoptera exigua. The structure of the telomeres of S. exigua was evaluated by sequence analysis of the TRAP products, revealing that the telomerase synthesized a (TTAGG)n repeat. The presence of a telomerase reverse transcriptase (TERT) subunit coding gene has been cloned, sequenced and expressed in vitro successively. Notably, the S. exigua telomerase (SpexTERT) gene structure lacks the N-terminal GQ motif. Telomerase contains a large RNA subunit, TER, and a protein catalytic subunit, TERT. Here we report an in vitro system that was reconstructed by all components of the telomerase complex, a purified recombinant SpexTERT without a N-terminal GQ motif and a mutant human telomerase RNA (TER), showed telomerase activity. Together, these results suggest the GQ motif is not essential for telomerase catalysis.
authors.affiliation: State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China; University of Chinese Academy of Sciences, Beijing, 100049, China.
authors.forename: H
authors.initials: H
authors.lastname: Gong
authors.forename: W
authors.initials: W
authors.lastname: Zhu
authors.forename: J
authors.initials: J
authors.lastname: Zhang
authors.forename: X
authors.initials: X
authors.lastname: Li
authors.forename: Q
authors.initials: Q
authors.lastname: Meng
authors.forename: G
authors.initials: G
authors.lastname: Zhou
authors.forename: M
authors.initials: M
authors.lastname: Wang
authors.forename: H
authors.initials: H
authors.lastname: Wang
authors.forename: L
authors.initials: L
authors.lastname: Miao
authors.forename: Q
authors.initials: Q
authors.lastname: Qin
authors.forename: H
authors.initials: H
authors.lastname: Zhang
mesh_terms: D020816:Amino Acid Motifs; D000818:Animals; D006801:Humans; D018411:Spodoptera / Q000235:genetics*; D020080:Tandem Repeat Sequences; D019098:Telomerase / Q000737:chemistry / Q000235:genetics*; D016615:Telomere / Q000235:genetics*
chemical_list: D019098:Telomerase
keywords: GQ motif; Spodoptera exigua; telomerase; telomeres