Fluoroaluminates activate transducin-GDP by mimicking the γ-phosphate of GTP in its binding site

• Published in: FEBS letters 1985-10, Vol.191 (2), p.181-185
• Main Authors: Bigay, Joëlle, Deterre, Philippe, Pfister, Claude, Chabre, Marc
• Format: Article
• Language: English
• Subjects: Adenylate cyclase; Aluminum; Aluminum - metabolism; Aluminum - pharmacology; Aluminum Compounds; Animals; Binding Sites; Biological and medical sciences; Cattle; Cell physiology; Fluoride; Fluorides; fluoroaluminate; Fundamental and applied biological sciences. Psychology; G-protein; GDP; GDPßS; Guanine Nucleotides - metabolism; guanosine 5 '-O-(3-thiodiphosphate); Guanosine Diphosphate - analogs & derivatives; Guanosine Diphosphate - metabolism; Guanosine Triphosphate - metabolism; Light; Membrane Proteins - metabolism; Membrane Proteins - radiation effects; Molecular and cellular biology; Phosphate; Phosphates - metabolism; photoexcited rhodopsin; Photoreceptor Cells - metabolism; Rod Cell Outer Segment - metabolism; Sodium Fluoride - pharmacology; Thionucleotides - metabolism; Transducin; Vision, photoreception
• ISSN: 0014-5793; 1873-3468
• DOI: 10.1016/0014-5793(85)80004-1

Fluoride activation of the cGMP cascade of vision requires the presence of aluminum, and is shown to be mediated by the binding of one AlF- 4 to the GDP/GTP-binding subunit of transducin. The presence of GDP in the site is required: AlF 4 − is ineffective when the site is empty or when GDPßS is substituted for GDP. This sensitivity to the sulfur of GDPßS suggests that AlF 4 − is in contact with the GDP. Striking structural similarities between AlF 4 − and PO 4 −1 lead us to propose that AlF 4 − mimics the role of the γ-phosphate of GTP.