Cell Signaling Technology

Product Pathways - Metabolism

Phospho-LKB1 (Ser428) (C67A3) Rabbit mAb #3482

Applications Reactivity Sensitivity MW (kDa) Isotype
W H M R Mk Endogenous 54 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-LKB1 (Ser428) (C67A3) Rabbit mAb detects endogenous levels of LKB1 when phosphorylated at Ser428.

Source / Purification

Monoclonal antibody is produced by immunizing animals with a synthetic phosphopeptide corresponding to residues surrounding Ser428 of human LKB1 (Ser431 of mouse).

Western Blotting

Western Blotting

Western blot analysis of extracts from various cell lines, untreated or treated with TPA #9905 and UV, using Phospho-LKB1 (Ser428) (C67A3) Rabbit mAb (upper) and LKB1 (D60C5) Rabbit mAb #3047 (lower).

Background

LKB1 (STK11) is a serine/threonine kinase and tumor suppressor that helps control cell structure, apoptosis and energy homeostasis through regulation of numerous downstream kinases (1,2). A cytosolic protein complex comprised of LKB1, putative kinase STRAD, and the MO25 scaffold protein, activates both AMP-activated protein kinase (AMPK) and several AMPK-related kinases (3). AMPK plays a predominant role as the master regulator of cellular energy homeostasis, controlling downstream effectors that regulate cell growth and apoptosis in response to cellular ATP concentrations (4). LKB1 appears to be phosphorylated in cells at several sites, 
including human LKB1 at Ser31/325/428 and Thr189/336/363 (5).Mutation in the corresponding LKB1 gene causes Peutz-Jeghers syndrome (PJS), an autosomal dominant disorder characterized by benign GI tract polyps and dark skin lesions of the mouth, hands and feet (6). A variety of other LKB1 gene mutations have been associated with the formation of sporadic cancers in several tissues (7).

Recent evidence suggests that phosphorylation at Ser428 by PKCζ influences the ability of LKB1 to bind and phosphorylate AMPK at Thr172 (8) as well as regulate apoptosis through PTEN signaling pathway suppression of Akt (9).

  1. Baas, A.F. et al. (2004) Trends Cell Biol 14, 312-9.
  2. Marignani, P.A. (2005) J Clin Pathol 58, 15-9.
  3. Lizcano, J.M. et al. (2004) EMBO J 23, 833-43.
  4. Hardie, D.G. (2004) J Cell Sci 117, 5479-87.
  5. Sapkota, G.P. et al. (2002) Biochem J 362, 481-90.
  6. Jenne, D.E. et al. (1998) Nat Genet 18, 38-43.
  7. Sanchez-Cespedes, M. (2007) Oncogene 26, 7825-32.
  8. Xie, Z. et al. (2006) J Biol Chem 281, 6366-75.
  9. Song, P. et al. (2008) J Biol Chem 283, 12446-55.

Application References

Have you published research involving the use of our products? If so we'd love to hear about it. Please let us know!

Companion Products

Rabbit monoclonal antibody is produced under license (granting certain rights including those under U. S. Patent No. 5,675,063) from Epitomics, Inc.

For Research Use Only. Not For Use In Diagnostic Procedures.

Products