Induction of eIF-4E phosphorylation by the addition of L-pyrroline-5-carboxylic acid to rabbit reticulocyte lysate.
Addition of L-pyrroline-5-carboxylic acid to reticulocyte lysates inhibits protein synthesis and induced phosphoproteins of 25 and 14 kDa. The 25 kDa phosphoprotein had the same Mr and pI as phosphorylated eIF-4E. Incubation of lysates with L-pyrroline-5-carboxylic acid did not alter the crosslinking of eIF-4E to reovirus mRNA caps. These results suggest that modifications of the translational apparatus other than eIF-4E phosphorylation may mediate the inhibitory effect seen with L-pyrroline-5-carboxylic acid and/or that phosphorylation of eIF-4E may effect functions subsequent to its interaction with the mRNA cap such as protein-protein interactions with other cap-specific translation factors.
Mick
S J
SJ
Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110.
Abramson
R D
RD
Ray
B K
BK
Merrick
W C
WC
Thach
R E
RE
Hagedorn
C H
CH
D000818:Animals; D039561:Eukaryotic Initiation Factor-4E; D066298:In Vitro Techniques; D007526:Isoelectric Point; D008970:Molecular Weight; D010448:Peptide Initiation Factors / Q000378:metabolism*; D010750:Phosphoproteins / Q000378:metabolism; D010766:Phosphorylation; D011500:Protein Synthesis Inhibitors; D011758:Pyrroles / Q000494:pharmacology*; D012315:RNA Caps / Q000378:metabolism; D011817:Rabbits; D012156:Reticulocytes
D039561:Eukaryotic Initiation Factor-4E; D010448:Peptide Initiation Factors; D010750:Phosphoproteins; D011500:Protein Synthesis Inhibitors; D011758:Pyrroles; D012315:RNA Caps; C015485:delta-1-pyrroline-5-carboxylate