The AMPK Subunit Antibody Sampler Kit provides an economical means to investigate the role played by all AMPK subunits in cellular energy homeostasis. The kit contains enough primary and secondary antibodies to perform two Western blots with each antibody.
Specificity / Sensitivity
Each of the antibodies in the AMPK Subunit Antibody Sampler Kit detects endogenous levels of the specified AMPK protein. Antibodies do not cross-react with related AMPK subunit proteins.
Source / Purification
Polyclonal antibodies are produced by immunizing animals with synthetic peptides corresponding to residues surrounding Leu519 near the carboxy terminus of human AMPKα1, corresponding to residues surrounding Ser500 of human AMPKα2, near the amino terminus of human AMPKγ1, surrounding Ser60 of human AMPKγ2, and corresponding to the sequences of human AMPKβ2 and AMPKγ3. Antibodies are purified by protein A and peptide affinity chromatography. Monoclonal antibody is produced by immunizing animals with synthetic peptides corresponding to residues surrounding Val176 of human AMPKβ1.
AMP-activated protein kinase (AMPK) is highly conserved from yeast to plants and animals and plays a key role in the regulation of energy homeostasis (1). AMPK is a heterotrimeric complex composed of a catalytic α subunit and regulatory β and γ subunits, each of which is encoded by two or three distinct genes (α1, 2; β1, 2; γ1, 2, 3) (2). The kinase is activated by an elevated AMP/ATP ratio due to cellular and environmental stress, such as heat shock, hypoxia, and ischemia (1). The tumor suppressor LKB1, in association with accessory proteins STRAD and MO25, phosphorylates AMPKα at Thr172 in the activation loop, and this phosphorylation is required for AMPK activation (3-5). AMPKα is also phosphorylated at Thr258 and Ser485 (for α1; Ser491 for α2). The upstream kinase and the biological significance of these phosphorylation events have yet to be elucidated (6). The β1 subunit is post-translationally modified by myristoylation and multi-site phosphorylation including Ser24/25, Ser96, Ser101, Ser108, and Ser182 (6,7). Phosphorylation at Ser108 of the β1 subunit seems to be required for AMPK activation, while phosphorylation at Ser24/25 and Ser182 affects AMPK localization (7). Several mutations in AMPKγ subunits have been identified, most of which are located in the putative AMP/ATP binding sites (CBS or Bateman domains). Mutations at these sites lead to reduction of AMPK activity and cause glycogen accumulation in heart or skeletal muscle (1,2). Accumulating evidence indicates that AMPK not only regulates the metabolism of fatty acids and glycogen, but also modulates protein synthesis and cell growth through EF2 and TSC2/mTOR pathways, as well as blood flow via eNOS/nNOS (1).