Related Experiment Video
Updated: Jul 10, 2026
09:16
Oligopeptide Competition Assay for Phosphorylation Site Determination
Published on: May 18, 2017
Structural insight into AMPK regulation: ADP comes into play
Xiangshu Jin1, Robert Townley, Lawrence Shapiro
1Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA.
Structure (London, England : 1993)
|October 17, 2007
Summary
AMP-activated protein kinase (AMPK) crystal structures reveal how ADP, AMP, ATP, and ZMP bind. ADP binds uniquely to a distinct site, suggesting a role in regulating cellular energy status.
Area of Science:
- Biochemistry
- Molecular Biology
- Structural Biology
Background:
- AMP-activated protein kinase (AMPK) is a crucial sensor of cellular energy status in eukaryotes.
- AMPK activity is modulated by intracellular adenosine nucleotide levels, particularly during metabolic stress.
Purpose of the Study:
- To elucidate the structural basis of nucleotide binding to the AMPK regulatory core.
- To investigate the binding modes of ADP, AMP, ATP, and ZMP (AICAR phosphate) to Schizosaccharomyces pombe AMPK.
Main Methods:
- X-ray crystallography was employed to determine the structures of AMPK core fragments bound to various nucleotides.
- Analysis of crystal structures to understand nucleotide interactions within Bateman domains A and B.
Main Results:
- Crystal structures revealed distinct binding sites for nucleotides in the AMPK gamma subunit.
- ZMP (AICAR phosphate) was observed to bind at the same site as AMP in Bateman domain B, mimicking AMP binding.
- ADP was found to bind selectively to an analogous site in Bateman domain A through unique interactions involving the beta subunit.
Conclusions:
- The findings provide detailed structural insights into how different nucleotides interact with AMPK.
- The distinct binding mode of ADP suggests a potential regulatory role in AMPK's response to cellular energy fluctuations.
Related Concept Videos
01:25cAMP-dependent Protein Kinase Pathways
Cyclic Adenosine Monophosphate (cAMP) is an essential second messenger that activates protein kinase A (PKA) and regulates various biological processes. A single epinephrine molecule binds to GPCR and activates several heterotrimeric G proteins, each stimulating multiple adenylyl cyclase, amplifying the signal, and synthesizing large numbers of cAMP molecules. Small changes in cAMP concentration affect PKA activity. The binding of four cAMP molecules induces a conformational change in PKA,...
01:22PI3K/mTOR/AKT Signaling Pathway
The mammalian target of rapamycin (mTOR) is a serine/threonine kinase that regulates growth, proliferation, and cell survival in response to hormones, growth factors, or nutrient availability. This kinase exists in two structurally and functionally distinct forms: mTOR complex 1 (mTORC1) and mTOR complex 2 (mTORC2). The first form (mTORC1) is composed of a rapamycin-sensitive Raptor and proline-rich Akt substrate, PRAS40. In contrast, mTORC2 consists of a rapamycin-insensitive companion...
01:28Global Regulatory Systems
Global regulatory systems in bacteria enable rapid and coordinated responses to environmental changes by integrating sensory inputs with gene expression, ensuring efficient adaptation to fluctuating conditions. Key global regulatory mechanisms include regulons, two-component systems, sigma factors, and secondary messengers.Regulons and Global RegulatorsA regulon is a collection of genes and operons controlled by a common global regulator. These regulators enable bacteria to prioritize resource...
01:09GPCRs Regulate Adenylyl Cylase Activity
Some GPCRs transmit signals through adenylyl cyclase (AC), a transmembrane enzyme. AC helps synthesize second messenger cyclic adenosine monophosphate (cAMP). AC catalyzes cyclization reaction and converts ATP to cAMP by releasing a pyrophosphate. The pyrophosphate is further hydrolyzed to phosphate by the enzyme pyrophosphatase, which drives cAMP synthesis to completion. However, cAMP is rapidly degraded to 5′ AMP by the enzymes phosphodiesterase (PDE), preventing overstimulation of cells.
Two...
Two...
01:22Amplifying Signals via Enzymatic Cascade
When a ligand binds to a cell-surface receptor, the receptor's intracellular domain changes shape, which may either activate its enzyme function or allow its binding to other molecules. The initial signal is amplified by most signal transduction pathways. This means that a single ligand molecule can activate multiple molecules of a downstream target. Proteins that relay a signal are most commonly phosphorylated at one or more sites, activating or inactivating the protein. Kinases catalyze the...
01:16Calmodulin-dependent Signaling
Calmodulin (CaM) is a calcium-binding protein in eukaryotes that controls various calcium-regulated cellular processes. It has four calcium-binding sites that bind calcium to form the calcium-calmodulin ( Ca2+-CaM) complex. GPCR stimulation increases the calcium levels in the cells that bind to CaM and induces a conformational change.
The Ca2+-CaM complex does not have enzymatic activity by itself. Instead, the complex binds downstream target proteins, including membrane proteins or enzymes,...
The Ca2+-CaM complex does not have enzymatic activity by itself. Instead, the complex binds downstream target proteins, including membrane proteins or enzymes,...