title: Are guanine nucleotide binding proteins a distinct class of regulatory proteins?
abstract: Proteins which bind guanine nucleotides are found in a diverse set of key regulatory positions. They are involved in hormone action, visual transduction, protein synthesis and microtubule assembly. In addition to their ability to bind guanine nucleotides these proteins possess several other common features. (i) They all have similar subunit composition, (ii) they can be ADP-ribosylated, (iii) their conformation changes depending on the nucleotide bound. These regulatory G-proteins have close functional homologies. Do they form a general class of regulatory proteins, like the protein kinases? Do they have a common evolutionary ancestry?
mesh_terms: D015106:3',5'-Cyclic-GMP Phosphodiesterases / Q000378:metabolism; D000246:Adenosine Diphosphate Ribose / Q000378:metabolism; D000262:Adenylyl Cyclases / Q000378:metabolism*; D000818:Animals; D019204:GTP-Binding Proteins; D005796:Genes; D010445:Peptide Elongation Factors / Q000378:metabolism; D010448:Peptide Initiation Factors / Q000378:metabolism; D010454:Peptide Termination Factors / Q000378:metabolism; D010786:Photoreceptor Cells / Q000201:enzymology; D014176:Protein Biosynthesis; D011956:Receptors, Cell Surface / Q000235:genetics / Q000378:metabolism*; D012243:Rhodopsin / Q000378:metabolism; D014404:Tubulin / Q000378:metabolism
chemical_list: D010445:Peptide Elongation Factors; D010448:Peptide Initiation Factors; D010454:Peptide Termination Factors; D011956:Receptors, Cell Surface; D014404:Tubulin; D000246:Adenosine Diphosphate Ribose; D012243:Rhodopsin; D015106:3',5'-Cyclic-GMP Phosphodiesterases; D019204:GTP-Binding Proteins; D000262:Adenylyl Cyclases