Cell Signaling Technology

Product Pathways - Cell Cycle / Checkpoint

Rb (4H1) Mouse mAb #9309

Applications Reactivity Sensitivity MW (kDa) Isotype
W IP IHC-P IF-IC F ChIP H Mk B Pg Endogenous 110 Mouse IgG2a

Applications Key:  W=Western Blotting  IP=Immunoprecipitation  IHC-P=Immunohistochemistry (Paraffin)  IF-IC=Immunofluorescence (Immunocytochemistry)  F=Flow Cytometry  ChIP=Chromatin IP
Reactivity Key:  H=Human  Mk=Monkey  B=Bovine  Pg=Pig
Species cross-reactivity is determined by western blot. Species enclosed in parentheses are predicted to react based on 100% sequence homology.

Protocols

Specificity / Sensitivity

Rb (4H1) Mouse mAb detects endogenous levels of total Rb protein. The antibody does not cross-react with the Rb homologues p107 or p130, or with other proteins.

Source / Purification

Monoclonal antibody is produced by immunizing animals with Rb-C Fusion Protein #6022, containing residues 701-928 of human Rb .

Western Blotting

Western Blotting

Western blot analysis of extracts from HeLa cells, transfected with 100 nM SignalSilence® Control siRNA (Fluorescein Conjugate) #6201 (-), SignalSilence® Rb siRNA I #6451 (+) or SignalSilence® Rb siRNA II (+), using Rb (4H1) Mouse mAb #9309 and α-Tubulin (11H10) Rabbit mAb #2125. The Rb (4H1) Mouse mAb confirms silencing of Rb expression, while the α-Tubulin (11H10) Rabbit mAb is used to control for loading and specificity of Rb siRNA.

Western Blotting

Western Blotting

Western blot analysis of extracts from COS-7 cells, untreated or hydroxyurea-treated (G1/S), using Rb (4H1) Mouse mAb.

IHC-P (paraffin)

IHC-P (paraffin)

Immunohistochemical analysis of paraffin-embedded human breast carcinoma, showing nuclear localization, using Rb (4H1) Mouse mAb.


IHC-P (paraffin)

IHC-P (paraffin)

Immunohistochemical analysis of paraffin-embedded human lung carcinoma, using Rb (4H1) Mouse mAb.

Flow Cytometry

Flow Cytometry

Flow cytometric analysis of Jurkat cells, using Rb (4H1) Mouse mAb versus propidium iodide (DNA content). The box indicates Rb positive cells.

IF-IC

IF-IC

Confocal immunofluorescent image of SH-SY5Y cells, using RB (4H1) Mouse mAb (green). Actin filaments have been labeled with Alexa Fluor® 555 phalloidin (red).


Chromatin IP

Chromatin IP

Chromatin immunoprecipitations were performed with cross-linked chromatin from 4 x 106 Raji cells and either 5 μl of Rb (4H1) Mouse mAb or 2 μl of Normal Rabbit IgG #2729 using SimpleChIP® Enzymatic Chromatin IP Kit (Magnetic Beads) #9003. The enriched DNA was quantified by real-time PCR using using SimpleChIP® Human Timeless Intron 1 Primers #7001, human DHFR promoter primers, and SimpleChIP® Human α Satellite Repeat Primers #4486. The amount of immunoprecipitated DNA in each sample is represented as signal relative to the total amount of input chromatin, which is equivalent to one.

Background

The retinoblastoma tumor suppressor protein, Rb, regulates cell proliferation by controlling progression through the restriction point within the G1-phase of the cell cycle (1). Rb has three functionally distinct binding domains and interacts with critical regulatory proteins including the E2F family of transcription factors, c-Abl tyrosine kinase, and proteins with a conserved LXCXE motif (2-4). Cell cycle-dependent phosphorylation by a CDK inhibits Rb target binding and allows cell cycle progression (5). Rb inactivation and subsequent cell cycle progression likely requires an initial phosphorylation by cyclin D-CDK4/6 followed by cyclin E-CDK2 phosphorylation (6). Specificity of different CDK/cyclin complexes has been observed in vitro (6-8) and cyclin D1 is required for Ser780 phosphorylation in vivo (9).

  1. Sherr, C.J. (1996) Science 274, 1672-7.
  2. Nevins, J.R. (1992) Science 258, 424-9.
  3. Welch, P.J. and Wang, J.Y. (1993) Cell 75, 779-90.
  4. Hu, Q.J. et al. (1990) EMBO J 9, 1147-55.
  5. Knudsen, E.S. and Wang, J.Y. (1997) Mol Cell Biol 17, 5771-83.
  6. Lundberg, A.S. and Weinberg, R.A. (1998) Mol Cell Biol 18, 753-61.
  7. Connell-Crowley, L. et al. (1997) Mol Biol Cell 8, 287-301.
  8. Kitagawa, M. et al. (1996) EMBO J 15, 7060-9.
  9. Geng, Y. et al. (2001) Proc Natl Acad Sci USA 98, 194-9.

Application References

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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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