Telomerase-associated proteins regulate telomerase activity and biogenesis of the ribonucleoprotein. Included are both telomerase reverse transcriptase (TERT) and telomerase RNA (TR) associated proteins. A standard nomenclature is used throughout the online database for consistency and clarity. Homologous proteins are given a single name for simplicity. Below are details on the interaction and fuction of each associated protein, the genbank accession numbers are linked to the record at the National Center for Biotechnology Information (NCBI), and original literature citations that are linked to the published online journal. The sequences are organized by taxon. Information within the table is derived from Cristofari, Lingner, et al (2006). Telomeres, 2nd edn. Cold Spring Harbor. Cold Spring Harbor Laboratory.
Vertebrates
| Vertebrates | Component | Interaction | Function | Remarks | Genbank ID | References | |
|---|---|---|---|---|---|---|---|
| Mammals | Homo sapiens (human) | hEst1A | telomerase activity (IP) | telomere elongation telomere capping | sequence similarities with budding yeast Est1 | AY145883 | Reichenbach et al, 2003 Snow et al, 2003 |
| hEst1B | telomerase activity (IP) | n.d. | sequence similarities with budding yeast Est1 | AY168922 | Reichenbach et al, 2003 Snow et al, 2003 |
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| hGar1p | hTR (bandshift/UV cross-link) | TR stability RNP assembly | NM_032993 | Fujii et al, 1991 Dragon et al, 2000 Wang et al, 2004 |
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| hNhp2 | hTR (bandshift/UV cross-link) | TR stability RNP assembly | NM_017838 | Pogacic et al, 2000 Wang et al, 2004 |
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| hNop10 | hTR (bandshift/UV cross-link) | TR stability RNP assembly | NM_018648 | Pogacic et al, 2000 Wang et al, 2004 |
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| dyskerin | hTR (IP, UV cross-link) | TR stability RNP assembly | mutated in X-linked form of dyskeratosis congenita | NM_001363 | Aalfs et al, 1995 Mitchell et al, 1999 Wang et al, 2004 |
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| SMN | telomerase activity (IP) | RNP assembly? Nucleolar localization of hTERT | AAH62723 (SMN1) NP_075013 (SMN2) | Bachand et al, 2002 | |||
| 14-3-3 | hTERT (2-hybrid, IP) | nuclear localization of hTERT | Seimya et al, 2000 | ||||
| Ku | telomerase activity (IP) hTR (bandshift, IP) | n.d. | Chai et al, 2002 Ting et al, 2005 |
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| La | hTR (UV cross-link, IP) | n.d. | Ford et al, 2001 | ||||
| Nucleolin | telomerase activity (IP) | nucleolar localization of hTERT | NM_005381 | Khunts et al, 2004 | |||
| PinX1 | TERT (IP) | inhibitor of telomerase activity | found in 2-hybrid screen with Pin2/TRF1 | Zhou et al, 2001 Banik et al, 2004 |
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| Hsp90 | hTERT (IP, 2-hybrid) | RNP assembly in vivo and in vitro | Holt et al, 1999 Forsythe et al, 2001 |
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| Hsp23 | hTERT (IP, 2-hybrid) | RNP assembly in vivo and in vitro | Holt et al, 1999 Forsythe et al, 2001 |
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| KIP | hTERT (2-hybrid) | positive regulator of telomere length | Lee et al, 2004 | ||||
| hnRNP A1 | telomerase activity (IP) | telomere elongation | Labranche et al, 1998 | ||||
| hnRNP C1/C2 | hTR (UV cross-link, IP) | n.d. | Ford et al, 2000 | ||||
| hnRNP D | telomerase activity (IP) | n.d. | Eversole et al, 2000 | ||||
| L22 | hTR (3-hybrid) | n.d. | Le et al, 2000 | ||||
| hStau | hTR (3-hybrid) | n.d. | Le et al, 2000 |
Fungi
| Fungi | Component | Interaction | Function | Remarks | Genbank ID | References | |
|---|---|---|---|---|---|---|---|
| Saccharomycotina | Schizosaccharomyces pombe (fission yeast) | SpEst1 | telomere elongation telomere capping | ortholog of yeast Est1 | O74804 | Beernink et al, 2003 | |
| Saccharomyces cerevisiae (baker's yeast) | Est1p | TLC1 (ever shorter telomeres genetic screen, IP) | binding of Cdc13p mediating telomerase recruitment and binding of telomeric DNA (not required for telomerase activity in vitro) | AAB67418 | Lundblad et al, 1989 Lendvay et al, 1996 Steiner et al, 1996 Linger et al 1997 Hughes et al, 2000 Evans et al, 2002 Seto et al, 2002 |
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| Est3p | Est3p (ever shorter telomeres genetic screen, IP) | telomere elongation in vitro (not required for telomerase activity in vitro) | NP_012256 | Lendvay et al, 1996 Morris et al, 1997 Linger et al 1997 Hughes et al, 2000 Friedman et al, 2003 |
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| Ku | TLC1 (allel-specific interactions, in vitro binding) | telomere elongation and chromosome healing | NP_014011 (KU 70) NP_013824 (KU 80) | Peterson et al, 2001 Stellwagen et al, 2003 Fisher et al, 2004 |
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| Cdc13p | Est1p (ever shorter telomeres genetic screen, IP) | binding of Est1p (not required for telomerase activity in vitro) | NP_010061 | Lendvay et al, 1996 Nugent et al, 1996 Linger et al 1997 Qi et al, 2000 Pennock et al, 2001 |
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| Sm proteins | TLC1 (IP) | TLC1 expression/stability and maturation | Q02260 (Sm D1) P43321 (Sm D3) |
Seto et al, 1999 | |||
| PinX1/Gno1p | Est2p (IP) | inhibitor of Est2p-TLC1 assembly | ortholog of human Pinx1 | AF432905 | Lin et al, 2004 |
Ciliates
| Ciliates | Component | Interaction | Function | Remarks | Genbank ID | References | |
|---|---|---|---|---|---|---|---|
| Oligohymenophorea | Tetrahymena thermophila | p75 | (TAP-TERT purification) | n.d. | AY522576 | Witkin et al, 2004 | |
| p65 | (TAP-TERT purification) | TER stability and RNP assembly | ortholog of E. aediculatus p43, contains a La Motif | AY280524 | Witkin et al, 2004 Prathapam et al, 2005 |
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| p45 | (TAP-TERT purification) | n.d. | AY280525 | Witkin et al, 2004 | |||
| p20 | (TAP-TERT purification) | n.d. | AY522577 | Witkin et al, 2004 | |||
| Spirotrich | Euplotes aediculatus | p43 | TR (copurification with telomerase activity and MS identification) | TER stability? Stimulates telomerase activity in vitro | ortholog of T. thermophila p65, contains a La motif | AF307939 | Lingner et al, 1996 Aigner et al, 2000 Aigner et al, 2003 Aigner et al, 2004 |