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 (Hm) (Sc) Endogenous 250 Rabbit

Applications Key:  W=Western Blotting  IHC-P=Immunohistochemistry (Paraffin)
Reactivity Key:  H=Human  M=Mouse  R=Rat  Hm=Hamster  Sc=S. cerevisiae
Species cross-reactivity is determined by western blot. Species enclosed in parentheses are predicted to react based on 100% sequence homology.

Protocols

Specificity / Sensitivity

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

Source / Purification

Polyclonal antibodies are produced by immunizing animals with a synthetic phosphopeptide 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, 21-9.
  2. Shilatifard, A. et al. (2003) Annu Rev Biochem 72, 693-715.
  3. Inukai, N. et al. (2004) J Biol Chem 279, 8190-5.
  4. Oelgeschläger, T. (2002) J Cell Physiol 190, 160-9.
  5. Luo, Z. et al. (2001) Mutat Res 486, 259-74.

Application References

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Companion Products

This product is intended for research purposes only. The product is not intended to be used for therapeutic or diagnostic purposes in humans or animals.

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