Characterization of sea urchin transglutaminase, a protein regulated by guanine/adenine nucleotides.
Transglutaminases (TGs) are calcium-dependent enzymes that catalyze the transamidation of glutamine residues to form intermolecular isopeptide bonds. Nine distinct TGs have been identified in mammals, and three of them (types 2, 3, and 5) are regulated by GTP/ATP and are able to hydrolyze GTP, working as bifunctional enzymes. We have isolated a cDNA clone encoding a TG from a cDNA library prepared from the blastula stage of sea urchin Paracentrotus lividus (PlTG). The cDNA sequence has an open reading frame coding for a protein of 738 amino acids, including a Cys active site and two other residues critical for catalytic activity, His and Asp. We have studied its expression pattern by in situ hybridization and have also demonstrated that the in vitro expressed PlTG had GTP- and ATP-hydrolyzing activity; moreover, GTP inhibited the transamidating activity of this enzyme as it does that of human TG2, TG3, and TG5.
Zanetti
Laura
L
Biochemistry and Molecular Biology Laboratory, Stazione Zoologica Anton Dohrn, 80121 Napoli, Italy.
Ristoratore
Filomena
F
Bertoni
Alessandra
A
Cariello
Lucio
L
D000225:Adenine / Q000737:chemistry*; D000251:Adenosine Triphosphatases / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000737:chemistry; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D020134:Catalytic Domain; D003001:Cloning, Molecular; D003545:Cysteine / Q000737:chemistry; D018076:DNA, Complementary / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D020558:GTP Phosphohydrolases / Q000378:metabolism; D015723:Gene Library; D005982:Glutathione Transferase / Q000378:metabolism; D006147:Guanine / Q000737:chemistry*; D006160:Guanosine Triphosphate / Q000737:chemistry; D006801:Humans; D006868:Hydrolysis; D017403:In Situ Hybridization; D007700:Kinetics; D008969:Molecular Sequence Data; D047328:Paracentrotus; D010957:Plasmids / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D011503:Transglutaminases / Q000737:chemistry*
D018076:DNA, Complementary; D011993:Recombinant Fusion Proteins; D006147:Guanine; D006160:Guanosine Triphosphate; D000255:Adenosine Triphosphate; D011503:Transglutaminases; D005982:Glutathione Transferase; D000251:Adenosine Triphosphatases; D020558:GTP Phosphohydrolases; D000225:Adenine; D003545:Cysteine