Exalpha Biologicals, Inc.

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FIX&PERM Cell Fixation and Permeabilization Kit

Flow cytometric analyses with monoclonal antibodies were so far mainly restricted to cell surface molecules. Intracellular structures such as cytoplasmic or nuclear enzymes, oncoproteins, cytokines, immunoglobulins etc. were largely excluded from such studies. Also excluded from flow cytometric studies were cytoplasmic localizations of well-established membrane molecules like CD3 and CD22, which, in their cytoplasmic form, are the most reliable lineage markers in undifferentiated leukemia. With the FIX&PERM® Kit flow cytometric analysis of intracellular antigens has become as easy as surface antigen studies. The only prerequisite is the availability of suitable antibody conjugates. Most of the available monoclonal antibody conjugates can be used with the FIX&PERM® Kit, some determinants are sensitive, however, to the fixation step involved. This and the optimal fixation time have to be tested for each reagent.


Welcome, Peter Rutten

We are pleased to announce that Peter Rutten has now started in his role as Operations Director here at Exalpha Biologicals Inc. Peter has a Master’s of Science degree in Industrial and Organizational Psychology and this has lead him down a very business orientated career path. Peter is looking forward to working with the team at Exalpha. Peters primary focus is the customer experience and he will be working with the Laboratory team, the Quality Control team and the Order Processing team to ensure this focus is achieved. We all wish Peter well in his new role.

Exalpha Biologicals, Inc.

phospho-4E-BP1 [pT46]

  • Product Code: X2009P
  • Size: 10 Miniblots
  • Availability: In Stock In Stock
  • Price (USD): $562

Cat #

X2009P		 Quantity:      

Data Sheet

Product Name

phospho- 4E-BP1 [pT46]





Product Type

Phosphorylation Site-Specific Antibody


Human, Mouse


Western Blot


Antigen Immunoaffiinity Purification


10 Miniblots

Price (USD)



Eukaryotic initiation factor 4E binding protein 1 (4E-BP1), also known as PHAS, is a ~20 kDa member of a family of eIF4E-binding proteins whose binding affinity to eIF4E is regulated by its phosphorylation. It inhibits cap-dependent translation by binding to eIF4E on the same site that overlaps the binding site for eIF4G, preventing its binding to the latter and eventually leading to an increase in mRNA translation. The phosphorylatin of 4E-BP1 is critical in determining cell fate by controlling translation initiation and apoptotic potency. 4E-BP1 is hyperphosphorylated in response to several external stimuli including hormones, growth factors, mitogens, cytokines and G-protein?coupled receptors and in response to stress conditions including nutrient deprivation. The phosphorylation of 4E-BP1 increases in response to activated phosphoinositol 3?-kinase (PI-3K) or its downstream effector Akt/PKB. 4E-BP1 is believed to mediate PI-3K and FRAP/mTOR signaling and is phosphorylated on at least six serine and threonine sites (Thr 37, Thr 46, Ser 65, Thr 70, Ser 83, and Ser 112). The phosphorylation of these sites is believed to occur in an orderly fashion where phosphorylation of threonine 37 and 46 by FRAP/mTOR is a priming step for subsequent phosphorylation of 4E-BP1 at the carboxy-terminal sites.


Chemically synthesized phosphopeptide derived from the region of human 4E-BP1 that contains threonine 46. The sequence is conserved in human, mouse and rat.

Positive Control

NIH3T3 cell lysate


Provided as solution in phosphate buffered saline, pH 7.3, with 1.0 mg/ml BSA and 0.05% sodium azide

Customer Storage

Product should be stored at -20°C. Aliquot to avoid freeze/thaw cycles

Target Molecular Weight

20 kDa

Product Image

Image Legend

Lysates prepared from NIH3T3 cells left untreated or treated with PI-3K inhibitor LY2904002 (lanes 2 & 3), prior to PDGF stimulation (lanes 1 & 3) and from EGF-treated HEK293 cells (4-8), Membranes were then left untreated (lanes 1-7) or treated with Lambda phosphatase (8), and incubated with 4E-BP1 [pT46] antibody for two hours at room temperature, following prior incubation with: no peptide (lanes 1 & 2), non-phosphopeptide corresponding to the immunogen (3), a generic phospho-threonine-containing peptide (4), or the phosphopeptide immunogen (5).

Database Links:



1. Stephens, L., et al. (2005) Phosphoinositide 3-kinases as drug targets in cancer.
Curr. Opin. Pharmacol. 5(4):357-365.
2. Zhou, L., et al. (2005) 4E-binding protein phosphorylation and eukaryotic initiation factor-4E release are required for airway smooth muscle hypertrophy. Am. J. Respir. Cell Mol. Biol. 33(2):195-202.
3. Greenberg, V.L. and S.G. Zimmer (2005) Paclitaxel induces the phosphorylation of the eukaryotic translation initiation factor 4E-binding protein 1 through a Cdk1-dependent mechanism. Oncogene 24(30):4851-4860.
4. Wang, X., et al. (2005) Distinct signaling events downstream of mTOR cooperate to mediate the effects of amino acids and insulin on initiation factor 4E-binding proteins. Mol. Cell Biol. 25(7):2558-2572.
5. Li, W. and B.E. Sumpio (2005) Strain-induced vascular endothelial cell proliferation requires PI3K-dependent mTOR-4E-BP1 signal pathway. Am. J. Physiol. Heart Circ. Physiol. 288(4):H1591-H1597.
6. Li, S., et al. (2002) Translational control of cell fate: availability of phosphorylation sites on translational repressor 4E-BP1 governs its proapoptotic potency. Mol. Cell Biol. 22(8):2853-2861.
7. Gingras, A.C., et al. (2001) Hierarchical phosphorylation of the translation inhibitor 4E-BP1. Genes Dev. 15(21):2852-2864.
8. Gingras, A.C., et al. (1999) Regulation of 4E-BP1 phosphorylation: a novel two-step mechanism. Genes Dev. 13(11):1422-1437.