Effect of newly identified hTERT-interacting proteins on telomerase activity

• Published in: Acta biochimica et biophysica Sinica 2013-08, Vol.45 (8), p.674-682
• Main Authors: Zhou, Lina, Chen, Bing, Hua, Xing, Zhou, Ping, Guo, Lian, Peng, Yong, Qiu, Kunhua
• Format: Article
• Language: English
• Subjects: Base Sequence; Cell Line, Tumor; DNA Primers; Enzyme-Linked Immunosorbent Assay; hTERT; Humans; Immunoprecipitation; Protein Binding; Reverse Transcriptase Polymerase Chain Reaction; Telomerase - metabolism; Two-Hybrid System Techniques; U-Pb年龄; 基因表达; 端粒酶活性; 端粒酶逆转录酶; 肿瘤细胞株; 蛋白质相互作用; 酵母双杂交系统
• ISSN: 1672-9145; 1745-7270
• DOI: 10.1093/abbs/gmt056

There is a close relationship between telomeres-telomerase and age-related disease. Human telomerase reverse tran- scriptase （hTERT） is both the catalytic component of human telomerase and the rate-limiting determinant of tel- omerase activity. Its transcriptional regulation is the primary mode of control of telomerase activity. It is critical to find the proteins interacting with hTERT for exploring the regulatory mechanisms of the hTERT expression and the telomerase activity. In this study, the yeast two-hybrid system was used to screen the potential interactive proteins of hTERT. Six proteins were obtained, among which T- STAR, LOXL3, HKR3, and Par-4 were further confirmed as the interacting proteins of hTERT by co-immunopreci- pitation. Then the sense and antisense gene eukaryotic ex- pression vectors containing these four genes were constructed and transfected into tumor cell lines. The cor- relations among the expression levels of these four proteins, the expression level of hTERT, and the telomerase activity were analyzed. Results showed that the up-regulation of T- STAR expression and down-regulation of HKR3 expression led to the increase of hTERT expression and telomerase ac- tivity, while the up- and down-regulation of LOXL3 and Par-4 expressions had no obvious effect. Our results sug- gested that T-STAR has a positive correlation with the tel- omerase activity while HKR3 may be a negative regulator. This conclusion is important to further explore the influen- cing factors or regulation pathways of human telomerase activity, which may be of great importance for the potential clinical application.