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MW (kDa)

Western Blotting

Western blot analysis of Rb-C Fusion Protein #6022 (amino acids 701-928 of Rb fused to MBP) before (-) and after (+) in vitro phosphorylation by cdc2/cyclin B Protein Kinase (New England Biolabs #P6020), using Phospho-Rb (Ser795) Antibody #9301 (left) or the control antibody (right).

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Product Description

Nonphosphorylated Rb-C Fusion Protein (5 µg/ml): Rb-C is expressed as a recombinant fusion protein of Rb residues 701–928 and maltose binding protein, serves as a negative control. Supplied in SDS Sample Buffer.

Phosphorylated Rb-C Fusion Protein (5 µg/ml): Prepared by in vitro kinase reaction with cdc2, serves as a positive control. Supplied in SDS Sample Buffer.

Molecular Formula:

Apparent Molecular Weight: Both the nonphosphorylated and phosphorylated forms of Rb-C migrate at an apparent molecular weight of 76 kDa by SDS-PAGE.

Product Usage Information

These lysates are useful controls for total and Phospho-Rb antibodies. However, this truncated Rb recombinant protein is not recognized by Phospho-Rb (Ser608) Antibody #2181, Phospho-Rb (Ser608) (D10F2) RmAb #8147, or Rb (D20) Rabbit mAb #9313.

Storage: Store at -20°C.

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.

Entrez-Gene Id 5925
Swiss-Prot Acc. P06400

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Rb Control Proteins