Cell Signaling Technology

Product Pathways - PathScan ELISA

PathScan® Phospho-Akt (Thr308) Sandwich ELISA Kit #7252

Kit Includes Volume Solution Color
Akt Rabbit Ab coated microwells 96 tests
Phospho-Akt (Thr308) Mouse Detection Ab 11 milliliter Green
Anti-mouse IgG HRP-Linked Ab 11 milliliter Red
TMB Substrate 11 milliliter Colorless
STOP Solution 11 milliliter Colorless
Sealing Tape 2 sheets
20X Wash Buffer 25 milliliter Colorless
Sample Diluent 25 milliliter Blue
Cell Lysis Buffer (10X) # 9803 15 milliliter Yellowish

Note: 12 8-well modules –Each module is designed to break apart for 8 tests.
Note: Kit should be stored at 4°C with the exception of Cell Lysis Buffer (10X), which is stored at –20°C (packaged separately).

Species Cross-Reactivity

H M

Reactivity Key:  H=Human  M=Mouse

Description

CST's PathScan® Phospho-Akt (Thr308) Sandwich ELISA Kit is a solid phase sandwich enzyme-linked immunosorbent assay (ELISA) that detects phospho-Akt (Thr308) protein. An Akt Antibody #9272* has been coated onto the microwells. After incubation with cell lysates, both phospho- and nonphospho-Akt proteins are captured by the coated antibody. Following extensive washing, Phospho-Akt (Thr308) Mouse mAb #5103* is added to detect the captured phospho-Akt protein. Anti-mouse IgG, HRP-linked Antibody #7076* is then used to recognize the bound detection antibody. HRP substrate, TMB, is added to develop color. The magnitude of optical density for this developed color is proportional to the quantity of phospho-Akt (Thr308) protein.* Antibodies in kit are custom formulations specific to kit.

Specificity / Sensitivity

CST's PathScan® Phospho-Akt (Thr308) Sandwich ELISA Kit #7252 detects endogenous levels of phospho-Akt (Thr308) protein. As shown in Figure 1, using Phospho-Akt (Thr308) ELISA Kit #7252, a significant induction of Phospho-Akt (Thr308) is detected in NIH/3T3 cells treated with PDGF. However, levels of total Akt (phospho and nonphospho) detected by PathScan® Total Akt Sandwich ELISA Kit #7170, remain unchanged (Figure 1). Phospho-Akt (Thr308) in Jurkat cells is also detected by this ELISA kit #7252.

Sandwich ELISA

Sandwich ELISA

Figure 2: The relationship between protein concentration of lysates from untreated and PDGF-treated NIH/3T3 cells and kit assay optical density readings is shown. After starvation, NIH/3T3 cells (85% confluence) were treated with PDGF (50 ng/ml) for 10 min at 37?C, and then lysed.

Sandwich ELISA

Sandwich ELISA

Figure 1: Treatment of NIH/3T3 cells with PDGF stimulates phosphorylation of Akt at Thr308, detected by PathScan® Phospho-Akt (Thr308) Sandwich ELISA Kit #7252, but does not affect the level of total Akt detected by PathScan® Total Akt1 Sandwich ELISA Kit #7170. OD 450 nm readings are shown in the top figure, while the corresponding Western blots using Phospho-Akt (Thr308) Antibody #9275 (right panel) or Akt Antibody #9272 (left panel), are shown in the bottom figure.

Background

Akt, also referred to as PKB or Rac, plays a critical role in controlling survival and apoptosis (1-3). This protein kinase is activated by insulin and various growth and survival factors to function in a wortmannin-sensitive pathway involving PI3 kinase (2,3). Akt is activated by phospholipid binding and activation loop phosphorylation at Thr308 by PDK1 (4) and by phosphorylation within the carboxy terminus at Ser473. The previously elusive PDK2 responsible for phosphorylation of Akt at Ser473 has been identified as mammalian target of rapamycin (mTor) in a rapamycin-insensitive complex with rictor and Sin1 (5,6). Akt promotes cell survival by inhibiting apoptosis by phosphorylating and inactivating several targets, including Bad (7), forkhead transcription factors (8), c-Raf (9) and caspase-9. PTEN phosphatase is a major negative regulator of the PI3 kinase/Akt signaling pathway (10). LY294002 is a specific PI3 kinase inhibitor (11).Another essential Akt function is the regulation of glycogen synthesis through phosphorylation and inactivation of GSK-3α and β (12,13). Akt may also play a role in insulin stimulation of glucose transport (12).In addition to its role in survival and glycogen synthesis, Akt is involved in cell cycle regulation by preventing GSK-3β mediated phosphorylation and degradation of cyclin D1 (14) and by negatively regulating the cyclin dependent kinase inhibitors p27 Kip (15) and p21 Waf1/CIP1 (16). Akt also plays a critical role in cell growth by directly phosphorylating mTOR in a rapamycin-sensitive complex containing raptor (17). More importantly, Akt phosphorylates and inactivates tuberin (TSC2), an inhibitor of mTOR within the mTOR-raptor complex (18). Inhibition of mTOR stops the protein synthesis machinery due to inactivation of its effector, p70 S6 kinase and activation of the eukaryotic initiation factor 4E binding protein 1 (4E-EP1), an inhibitor of translation (18,19).

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  2. Burgering, B.M. and Coffer, P.J. (1995) Nature 376, 599-602.
  3. Franke, T.F. et al. (1995) Cell 81, 727-36.
  4. Alessi, D.R. et al. (1996) EMBO J 15, 6541-51.
  5. Sarbassov, D.D. et al. (2005) Science 307, 1098-101.
  6. Jacinto, E. et al. (2006) Cell 127, 125-37.
  7. Cardone, M.H. et al. (1998) Science 282, 1318-21.
  8. Brunet, A. et al. (1999) Cell 96, 857-68.
  9. Zimmermann, S. and Moelling, K. (1999) Science 286, 1741-4.
  10. Cantley, L.C. and Neel, B.G. (1999) Proc Natl Acad Sci USA 96, 4240-5.
  11. Vlahos, C.J. et al. (1994) J Biol Chem 269, 5241-8.
  12. Hajduch, E. et al. (2001) FEBS Lett 492, 199-203.
  13. Cross, D.A. et al. (1995) Nature 378, 785-9.
  14. Diehl, J.A. et al. (1998) Genes Dev 12, 3499-511.
  15. Gesbert, F. et al. (2000) J Biol Chem 275, 39223-30.
  16. Zhou, B.P. et al. (2001) Nat Cell Biol 3, 245-52.
  17. Nave, B.T. et al. (1999) Biochem J 344 Pt 2, 427-31.
  18. Inoki, K. et al. (2002) Nat Cell Biol 4, 648-57.
  19. Manning, B.D. et al. (2002) Mol Cell 10, 151-62.

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