Fluoroaluminates activate transducin-GDP by mimicking the gamma-phosphate of GTP in its binding site.
Fluoride activation of the cGMP cascade of vision requires the presence of aluminum, and is shown to be mediated by the binding of one A1F-4 to the GDP/GTP-binding subunit of transducin. The presence of GDP in the site is required: A1F-4 is ineffective when the site is empty or when GDP beta S is substituted for GDP. This sensitivity to the sulfur of GDP beta S suggests that A1F-4 is in contact with the GDP. Striking structural similarities between A1F-4 and PO3-4 lead us to propose that A1F-4 mimics the role of the gamma-phosphate of GTP.
D000535:Aluminum / Q000378:metabolism / Q000494:pharmacology*; D017607:Aluminum Compounds; D000818:Animals; D001665:Binding Sites; D002417:Cattle; D005459:Fluorides; D006150:Guanine Nucleotides / Q000378:metabolism*; D006153:Guanosine Diphosphate / Q000031:analogs & derivatives / Q000378:metabolism*; D006160:Guanosine Triphosphate / Q000378:metabolism*; D008027:Light; D008565:Membrane Proteins / Q000378:metabolism* / Q000528:radiation effects; D010710:Phosphates / Q000378:metabolism*; D010786:Photoreceptor Cells / Q000378:metabolism*; D012374:Rod Cell Outer Segment / Q000378:metabolism*; D012969:Sodium Fluoride / Q000494:pharmacology; D013873:Thionucleotides / Q000378:metabolism; D015293:Transducin
D017607:Aluminum Compounds; D006150:Guanine Nucleotides; D008565:Membrane Proteins; D010710:Phosphates; D013873:Thionucleotides; D006153:Guanosine Diphosphate; C023427:guanosine 5'-O-(2-thiodiphosphate); D006160:Guanosine Triphosphate; D012969:Sodium Fluoride; D000535:Aluminum; D015293:Transducin; D005459:Fluorides; C032311:aluminum fluoride