Tankyrase
Home Up Anti T TACE TR1 & TR2 TAU TRF1 ADP, TNK2 Tankyrase Telomerase/Est2 1 TIM circadian protein THTR1 THRx, fusion protein Thyroid Hydroxylase Thyroid Iodide Transporter, TIT Tie-1 & Tie-2 Topoisomerase DNA repair TP1/TLP1 TfR1 & Tfr 2 TRF-1 & 2 Tub homolog, Human 1/2 TULP1 é 2

 

 

Telomerase, TRF1, TRF2, TP1, antibodies and positive controls

 

 

The 3'ends of chromosomes are capped with telomere sequences (TTAGGG; 6-26 nucleotides in length) by ribonucleoprotein telomerase during DNA replication. Telomerase is an unusual RNA-dependent DNA polymerase that uses and RNA component to specify the addition of telomere. The telomeric RNA contains a sequence complementary to TTAGGG. In ciliated protozoa and yeast, telomere length is maintained by regulating the activity of telomerase. Approx. 4.8 kb of telomeric DNA is lost with each cell division. Many mammalian cells do not express telomerase resulting into shortening of telomere with each cell division, and ultimately causing the chromosomal instability, aging and cell death. Interesting, most transformed, immortalized or tumor cells continue to express telomerase. Transgenic mice, lacking the RNA-component of telomerase, had no telomerase activity. However, TR-/- animals survived for at least 6 generations. Most recently, introduction of telomerase into normal human cells has been shown to extend normal cell life by ~ 20 doubling.

Telomerase activity has been detected in a wide variety of eukaryotic species, including yeast, ciliates, Xenopus, mouse and human. Recent studies examining the expression of human RNA component (hTR) showed no correlation between the hTR expression levels and telomerase activity. Protein component of telomerase have only recently been cloned and characterized. In Tetrahymena, proteins of mol wt 80 and 90 kDa copurify with telomerase. The p80 subunit binds to telomerase RNA, whereas p80 binds to single-stranded telomeric DNA.

The first mammalian homolog of Tetrahymena p80 telomerase-associated protein, TP1/TLP1 (telomerase protein component 1) has been cloned. The mouse/rat TP1 (2629 aa) and human TP1 (2627 aa) proteins (~230-240 kDa) lacks any RNA-dependent DNA polymerase domain indicating that TP1 may be associated with a catalytic subunit in a multipcomponent telomerase complex. Unlike p80, TP1/TLP1 contain functional WD-40 repeats, a motif known to mediate protein-protein interaction.

Purification of telomerase from the ciliate also revealed two protein of 43 and 123 kDa. p123 is a homolog of yeast Est2 (Essential for Telomerase activity) and show 20% homology.. Mammalian homologs of yeast Est2 (also known as TP2 for Telomerase associated Protein 2; hEST2 or telomerase catalytic subunit or telomerase reverse transcriptase, TERT) have also been cloned (human Est2, 1132 aa; mouse Est2 1122 aa; ~127 kDa). hEST2 was localized in the nucleus. It is associated with telomerase activity and TP1.

Telomeric Repeat binding Factors (TRF1 and TRF2) bind the telomeric TTAGGG repeat. TRFs have been colocalized with telomeric DNA in metaphase cells. TRFs are located at chromosome ends during metaphase. Mouse and human TRF1 are 421 aa and 439 aa, respectively. TRF1 and TRF2 share ~30% homology. TRF2 protects chromosome ends and TRF1 regulates telomere length. Over expression of TRF1 resulted into telomere shortening, whereas inhibition of TRF1 increased telomere length.

ADI has produced highly specific antibodies to hEST2, TRF1, TRF2, TP1, and Tankyrase. Appropriate immunogenic peptides (control peptide) are also available to check for antibody activity by ELISA, dot blot and for antibody blocking. Control peptides, because of their small size, are not suitable for western blotting. They are suitable for antibody blocking.

 

 Items

 Antigen
peptide
location

 Ab
Host

  Ab Cross-
reactivity

 Neat Antisera
Cat #
(100 ul)

 Aff. Pure Ab
Cat #
(100 ug)

* Control Peptide Cat# (100 ug)

**WB +ve
Controls
Cat # 

 hEst2 (Ab #1)

 h, 16 aa, I

Rb

 h (m, r?)

EST21-S

 EST21-A

  EST21-P

EST21-C

hEst2 (Ab #2)

h, 21aa, I

 Rb

h (m, r?)

EST22-S

 EST22-A

 EST22-P

-

 mEst2 (Ab #3)

m, 15 aa, I

Rb 

m (h, r?)

 EST23-S

EST23-A

 EST23-P

EST23-C

yEst2 (Ab #4)

y, 23 aa, I

Rb

y

 EST24-S

EST24-A

EST24-P

- 

 

 yEst2 (Ab #5)

 

 y, 23 aa, I

 

 Ch

 

 y

 

 EST25-S

 

 -

 

 EST25-P

 

 

 hTRF1 (Ab #1)

 

h, 20 aa, I

 

Rb

 

h

 

TRF11-S

 

 TRF11-A

 

 TRF11-P

 

TRF11-C

 

 mTRF1 (Ab #2)

 

m, 20 aa, I

 

Rb

 

m

 

TRF12-S

 

TRF12-A

 

 TRF12-P

 

 TRF12-C

 

 mTRF2 (Ab #1)

 

m, 21 aa, I

 

Rb

 

m, r, h

 

TRF21-S

 

 TRF21-A

 

 TRF21-P

 

TRF21-C

 

 mTP1 (Ab #1)

 

m, 19 aa, I

 

Rb

 

m, r, h

 

TP11-S

 

TP11-A

 

TP11-P

 

-

 

 Control Rabbit IgG

 

For use in ELISA, Western, Immunohistochemistry 20009-1 (1 mg)
Control Chicken IgG For use in ELISA, Western, Immunohistochemistry, Cat # 20010-1 (1 mg)

 

Western blot +ve controls are prepared from appropriate tissues/cell lines (load 10 ul/lane to visualize appropriate proteins). m=mouse; r=rat; h=human; y=yeast; Rb=rabbit; Ch=chicken; NT=near N-terminus; CT=near C-terminus; I=Internal or middle peptide sequences

Control peptides, because of thier small sizes (1-3K) are not suitable for Western. They are intended for ELISA or antibody competition studies. These are provided as "free" or unconjugated forms.
Neat Antiserum represents crude, undiluted, and non-purified serum. It is is OK for studies in Western or ELISA.
Affinity pure antibodies (purified over the antigen/peptide columns), in general, will give cleaner background and recommended for IHC or IP applications.

List of publications using ADI's Telomerase/Est2

Telomerase/Est2 

Zhang P 2003 FASEB J Feb 2003 in press TERT suppresses apoptotis at a premitochondrial step by a mechanism requiring reverse transcriptase activity and 14-3-3 protein binding ability, IHC used 1:3K; also AIF/mab. 

 

Telomerase/Est2 Hiyama E 2003 Cancer Lett. in press Telomerase as tumor marker IHC bronchial biopsy sample obtained from a patient with squamous cell carcinoma of the lung/EST21-A.

 

TRF2 

Oh H 2003 Telomere attrition and Chk2 activation in human heart failure PNAS, Apr 2003; 100: 5378 - 5383. WB IHC rat.

 

Telomerase/Est2 Hiyama, E et al 2001 Neoplasia, 2001, 3, 17-26 Immunohistochemical detection of telomerase (hTERT) protein in human cancer tissues and a subset of cells in normal tissues paraffin section, est21-c.

 

Telomerase/Est2 Xiang Hua et al 2000 BBRC 278, 503-510, hTERT Can Function with Rabbit Telomerase RNA: Regulation of Gene Expression and Attenuation of Apoptosis.

Notes: Antibodies usage is indicated in the following techniques: WB=Western Blot ; IHC-Immunohistochmistry; IP=Immunoprecipition; Flow=Flow cytometry;