ADP-ribosylation of membrane proteins catalyzed by cholera toxin: basis of the activation of adenylate cyclase.
AUTOR(ES)
Gill, D M
RESUMO
In the presence of ATP and a cytosolic factor, cholera toxin fragment A1 catalyzes the transfer of ADP-ribose from NAD to a number of soluble and membrane-bound proteins of the pigeon erythrocyte. Evidence is presented that suggests that the most readily modified membrane protein (Mr 42,000) is the adenylate cyclase-associated GTP-binding protein. Its modification by toxin is stimulated by guanine nucleotides. Adenylate cyclase activity increases in parallel with the addition of ADP-ribose to this protein and decreases in parallel with the subsequent reversal of ADP-ribosylation by toxin and nicotinamide. The protein is only accessible to toxin A subunits if the erythrocytes are lysed. When adenylate cyclase activity reaches a maximum, the number of ADP-ribose residues bound to this protein (about 1500 per cell) is similar to the reported number of beta-adrenergic receptors.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=392711Documentos Relacionados
- ADP-ribosylation of microtubule proteins as catalyzed by cholera toxin.
- Direct modification of the membrane adenylate cyclase system by islet-activating protein due to ADP-ribosylation of a membrane protein.
- Importance of ADP-ribosylation in the morphological changes of PC12 cells induced by cholera toxin.
- Mechanism of action of glycopeptide hormones and cholera toxin: what is the role of ADP-ribosylation?
- Reconstitution of cholera toxin-activated adenylate cyclase.