Extratelomeric functions of telomerase.
Telomerase reverse transcriptase (TERT), a catalytic subunit of telomerase, has been demonstrated to exert a reverse transcriptase function when combined with telomerase RNA component (TERC), the complex of which ensures the maintenance of telomere length in all eukaryotes. Telomerase also prevents cell death, and promotes survival in many types of cells, from various tissues or organs including neurons, muscle, and immune cells, as well as a variety of tumor cells. Recently, a new aspect of telomerase activity, independent of telomere lengthening, has emerged to explain its protective effects on cell survival. Consistent with this, TERT was found to enhance tumorigenesis, and to regulate the expression of genes that control cell growth, which cannot be explained by telomere stabilization per se. Furthermore, the observation that TERT resides not only in the nucleus, but also in the cytosol, reinforces the notion of possible telomere-independent functions. In this review, recent studies regarding the extratelomeric functions of TERT have been comprehensively summarized, and their implications discussed.
Department of Molecular Cell Biology, Sungkyunkwan University School of Medicine, Samsung Biomedical Research Institute, Suwon 440-746, Korea.
Hee Kyoung
HK
Chung
Cheolho
C
Cheong
Jaewhan
J
Song
Han-Woong
HW
Lee
D000818:Animals; D002467:Cell Nucleus / Q000201:enzymology; D003593:Cytoplasm / Q000201:enzymology; D004260:DNA Repair; D004268:DNA-Binding Proteins; D005786:Gene Expression Regulation; D006801:Humans; D051379:Mice; D032342:Muscle Cells / Q000201:enzymology; D013601:T-Lymphocytes / Q000201:enzymology; D019098:Telomerase / Q000032:analysis / Q000502:physiology*; D016615:Telomere / Q000378:metabolism
D004268:DNA-Binding Proteins; C509186:TERT protein, human; D019098:Telomerase; C509187:Tert protein, mouse