Cell Signaling Technology

Product Pathways - Wnt / Hedgehog / Notch

Phospho-Numb (Ser276) Antibody #4140

Applications Reactivity Sensitivity MW (kDa) Source
W H M R Mk Endogenous 72, 74 Rabbit

Applications Key:  W=Western Blotting
Reactivity Key:  H=Human  M=Mouse  R=Rat  Mk=Monkey
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-Numb (Ser276) Antibody detects endogenous levels of Numb protein only when phosphorylated on Ser276.

Source / Purification

Polyclonal antibodies are produced by immunizing animals with a synthetic phosphopeptide corresponding to Ser276 of the human Numb protein. Antibodies are purified by protein A and peptide affinity chromatography.

Western Blotting

Western Blotting

Western blot analysis of extracts from Ramos and HeLa cells, untreated or treated with TPA (Phorbol-12-Myristate-13-Acetate, 200 nM for 30 min) or λ-phosphatase, using Phospho-Numb (Ser276) Antibody (upper) or Numb (C29G11) Rabbit mAb #2756 (lower).

Background

Numb contains an amino-terminal phosphotyrosine-binding (PTB) domain and carboxy-terminal endocytic binding motifs for α-adaptin and EH (Eps15 homology) domain-containing proteins, indicating a role in endocytosis (1,2). There are four mammalian Numb splicing isoforms that are differentially expressed and may have distinct functions (3-5). Numb acts as a negative regulator of Notch signaling by promoting ubiquitination and degradation of Notch (6). The protein is asymmetrically segregated into one daughter cell during cell division, producing two daughter cells with different responses to Notch signaling and different cell fates (7,8). The localization of Numb can also be regulated by G-protein coupled receptor (GPCR) and PKC signaling (9).

Numb can be phosphorylated at several sites including Ser7, Ser276 and Ser295. Phosphorylation at these sites regulates asymmetric membrane localization of Numb and integrin endocytosis (10-12).

  1. Berdnik, D. et al. (2002) Dev. Cell 3, 221-231.
  2. Santolini, E. et al. (2000) J. Cell Biol. 151, 1345-1352.
  3. Dho, S.E. et al. (1999) J. Biol. Chem. 274, 33097-33104.
  4. Verdi, J.M. et al. (1999) Proc. Natl. Acad. Sci. USA 96, 10472-10476.
  5. Toriya, M. et al. (2006) Dev. Neurosci. 28, 142-155.
  6. McGill, M.A. and McGlade, C.J. (2003) J. Biol. Chem. 278, 23196-23203.
  7. Verdi, J.M. et al. (1996) Curr. Biol. 6, 1134-1145.
  8. Reugels, A.M. et al. (2006) Dev. Dyn. 235, 934-948.
  9. Dho, S.E. et al. (2006) Mol. Biol. Cell 17, 4142-4155.
  10. Nishimura, T. and Kaibuchi, K. (2007) Dev Cell 13, 15-28.
  11. Smith, C.A. et al. (2007) EMBO J. 26, 468-480.
  12. Wirtz-Peitz, F. et al. (2008) Cell 135, 161-173.

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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