Document 0253
 DOCN  M9550253
 TI    Identification of a substrate site for transglutaminases on the human
       protein synthesis initiation factor 5A.
 DT    9505
 AU    Beninati S; Nicolini L; Jakus J; Passeggio A; Abbruzzese A; Department
       of Biology, II University of Rome Tor Vergata, Italy.
 SO    Biochem J. 1995 Feb 1;305 ( Pt 3):725-8. Unique Identifier : AIDSLINE
       MED/95151003
 AB    Protein synthesis initiation factor 5A (eIF-5A) from human erythrocytes
       was found to be a substrate for both plasma transglutaminase (Factor
       XIIIa) and guinea pig liver transglutaminase (GPLTG). When purified
       eIF-5A was incubated with GPLTG or Factor XIIIa in the presence of
       succinylated beta-casein, a covalent complex was identified. By
       isolating and analysing the product of the transglutaminases (TGases)
       reaction, the site of modification on eIF-5A has been identified as the
       unique amino acid hypusine. The complex beta-casein.eIF-5A was
       enzymatically digested with proteinases and the predicted covalent
       cross-link of gamma-glutamyl-omega-hypusine was isolated from the
       digests by ion-exchange chromatography and purified by reversed-phase
       h.p.l.c. Acid hydrolysis of the purified dipeptide yielded equimolar
       amounts of hypusine and glutamic acid. Furthermore, fast atom
       bombardment m.s. analysis confirmed the isomer assignment to be
       gamma-glutamyl-omega-hypusine. These data indicate that hypusine-50 of
       the eIF-5A chain functions as acyl acceptor substrate for TGases, and
       reveal that eIF-5A may be cross-linked to intracellular proteins by
       TGases. Because the precise function of eIF-5A is still unknown, our
       results appear particularly stimulating in the light of the recent
       finding of a new biological role for this protein as a cellular factor
       binding specifically to the human immunodeficiency virus-1 Rev
       activation domain [Ruhl, Himmelspach, Bahr, Hammerschmid, Jaksche,
       Wolff, Auschauer, Farrington, Probst, Bevec and Hauber (1993) J. Cell
       Biol. 123, 1309-1320].
 DE    Animal  Binding Sites  Caseins/METABOLISM  Chromatography, High Pressure
       Liquid  Chromatography, Ion Exchange  Electrophoresis, Polyacrylamide
       Gel  Erythrocytes/CHEMISTRY  Glutamic Acid/METABOLISM  Guinea Pigs
       Human  Kinetics  Liver/ENZYMOLOGY  Lysine/ANALOGS &
       DERIVATIVES/METABOLISM  Peptide Initiation Factors/CHEMISTRY/*METABOLISM
       Protein-Glutamine gamma-Glutamyltransferase/*METABOLISM  Support,
       Non-U.S. Gov't  Support, U.S. Gov't, P.H.S.  JOURNAL ARTICLE

       SOURCE: National Library of Medicine.  NOTICE: This material may be
       protected by Copyright Law (Title 17, U.S.Code).