Cell Signaling Technology

Product Pathways - Cell Cycle / Checkpoint

Phospho-Rpb1 CTD (Ser2/5) Antibody #4735

Applications Reactivity Sensitivity MW (kDa) Source
W IHC-P H M R (Sc) (Hm) Endogenous 250 Rabbit

Applications Key:  W=Western Blotting  IHC-P=Immunohistochemistry (Paraffin)
Reactivity Key:  H=Human  M=Mouse  R=Rat  Sc=S. cerevisiae  Hm=Hamster
Species cross-reactivity is determined by Western blot.

Protocols

Specificity / Sensitivity

Phospho-Rpb1 CTD (Ser2/5) Antibody detects endogenous levels of Rpb1 only when the carboxy-termial domain heptapeptide repeat [Tyr1,Ser2,Pro3,Thr4,Ser5,Pro6,Ser7] is phosphorylated at Ser2/5.

Source / Purification

Polyclonal antibodies are produced by immunizing rabbits with a synthetic phospho-peptide (KLH-coupled) corresponding to residues surrounding Ser2/5 of the Rpb1 CTD heptapeptide. Antibodies are purified by protein A and peptide affinity chromatography.

Western Blotting

Western Blotting

Western blot analysis of extracts from MCF-7 cells, untreated or treated with doxorubicin (0.5 μM, 36 h), doxorubicin followed by λ Phosphatase NEB#P0753 (10,000 Units/ml, 1 h), nocodazole (50 ng/ml, 36 h) or nocodazole followed by λ Phosphatase, using Phospho-Rpb1 CTD (Ser2/5) Antibody (upper) or p53 Antibody #9282 (lower).

IHC-P (paraffin)

IHC-P (paraffin)

Immunohistochemical analysis of paraffin-embedded human renal cell carcinoma, untreated (left) or λ phosphatase-treated (right), using Phospho-Rpb1 CTD (Ser2/5) Antibody.

IHC-P (paraffin)

IHC-P (paraffin)

Immunohistochemical analysis of paraffin-embedded human lung carcinoma, showing nuclear localization, using Phospho-Rpb1 CTD (Ser2/5) Antibody.


IHC-P (paraffin)

IHC-P (paraffin)

Immunohistochemical analysis of paraffin-embedded human colon carcinoma, using Phospho-Rpb1 CTD (Ser2/5) Antibody in the presence of control peptide (left) or antigen-specific peptide (right).

Background

RNA polymerase II is a complex of 12 proteins that participates in transcription, mRNA processing, and transcription-coupled DNA repair (1,2). The largest subunit, Rpb1, contains a unique heptapeptide: Tyr1, Ser2, Pro3, Thr4, Ser5, Pro6, Ser7, which is repeated up to 52 times in the carboxy-terminal domain (CTD) of Rpb1 (3). This CTD is phosphorylated by cyclin-dependent kinases (CDKs), p44/42 MAPK, DNA-PKcs, and c-Abl (4). DNA damage caused by UV-light, hydrogen peroxide, or cisplatin results in ubiquitination and proteasomal degradation of Rpb1 (1,3). The kinase inhibitor 5,6-dichloro-1-β-D-ribofuranosylbenzimidazole prevents ubiquitination of Rpb1, suggesting that CTD phosphorylation is required for proteolysis (5).

  1. Svejstrup, J.Q. (2002) Nat. Rev. Mol. Cell. Biol. 3, 21-29.
  2. Shilatifard, A. et al. (2003) Annu. Rev. Biochem. 72, 693-715.
  3. Inukai, N. et al. (2004) J. Biol. Chem. 279, 8190-8195.
  4. Oelgeschlager, T. et al. (2002) J. Cell. Physiol. 190, 160-169.
  5. Luo, Z. et al. (2001) Mutat. Res. 486, 259-274.

Application References

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Companion Products

This product is for in vitro research use only and is not intended for use in humans or animals. This product is not intended for use as therapeutic or in diagnostic procedures.

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