CBS domains form energy-sensing modules whose binding of adenosine ligands is disrupted by disease mutations

• Published in: The Journal of clinical investigation 2004-01, Vol.113 (2), p.274-284
• Main Authors: Scott, John W, Hawley, Simon A, Green, Kevin A, Anis, Miliea, Stewart, Greg, Scullion, Gillian A, Norman, David G, Hardie, D Grahame
• Format: Article
• Language: English
• Subjects: Adenosine; Adenosine - chemistry; Adenosine Monophosphate - chemistry; Adenosine Monophosphate - metabolism; Adenosine Triphosphate - chemistry; Adenosine Triphosphate - metabolism; Allosteric Site; Amino Acid Motifs; Amino acids; Animals; Binding Sites; Biomedical research; Cloning; Cloning, Molecular; Congenital diseases; Dehydrogenases; Diabetes; Dimerization; DNA - metabolism; DNA, Complementary - metabolism; Dose-Response Relationship, Drug; Energy; Epilepsy; Escherichia coli - metabolism; Glutathione Transferase - metabolism; Humans; Kidney stones; Kinases; Kinetics; Ligands; Liver - metabolism; Metabolic syndrome; Models, Molecular; Mutation; Obesity; Plasmids - metabolism; Polymerase Chain Reaction; Protein Binding; Protein Isoforms; Protein Structure, Tertiary; Proteins; Rats; Recombinant Fusion Proteins - metabolism; Recombinant Proteins - chemistry; Retinitis Pigmentosa - pathology
• ISSN: 0021-9738; 1558-8238
• DOI: 10.1172/JCI200419874

CBS domains are defined as sequence motifs that occur in several different proteins in all kingdoms of life. Although thought to be regulatory, their exact functions have been unknown. However, their importance was underlined by findings that mutations in conserved residues within them cause a variety of human hereditary diseases, including (with the gene mutated in parentheses): Wolff-Parkinson-White syndrome (gamma 2 subunit of AMP-activated protein kinase); retinitis pigmentosa (IMP dehydrogenase-1); congenital myotonia, idiopathic generalized epilepsy, hypercalciuric nephrolithiasis, and classic Bartter syndrome (CLC chloride channel family members); and homocystinuria (cystathionine beta-synthase). AMP-activated protein kinase is a sensor of cellular energy status that is activated by AMP and inhibited by ATP, but the location of the regulatory nucleotide-binding sites (which are prime targets for drugs to treat obesity and diabetes) was not characterized. We now show that tandem pairs of CBS domains from AMP-activated protein kinase, IMP dehydrogenase-2, the chloride channel CLC2, and cystathionine beta-synthase bind AMP, ATP, or S-adenosyl methionine,while mutations that cause hereditary diseases impair this binding. This shows that tandem pairs of CBS domains act, in most cases, as sensors of cellular energy status and, as such, represent a newly identified class of binding domain for adenosine derivatives.