PMID- 1989989
OWN - NLM
STAT- MEDLINE
DCOM- 19910307
LR  - 20210210
IS  - 0021-9258 (Print)
IS  - 0021-9258 (Linking)
VI  - 266
IP  - 4
DP  - 1991 Feb 5
TI  - Insulin induction of ornithine decarboxylase. Importance of mRNA secondary 
      structure and phosphorylation of eucaryotic initiation factors eIF-4B and eIF-4E.
PG  - 2383-9
AB  - We investigated the possibility that insulin could stimulate translation of 
      ornithine decarboxylase (ODC) mRNA in a murine fibroblast cell line that 
      expresses large numbers of human insulin receptors (HIR 3.5 cells). Within 3 h 
      after exposure to 70 nM insulin, ODC enzyme activity increased approximately 
      50-fold and mRNA accumulation 3-fold in the HIR 3.5 cells but not in normal 
      fibroblasts. Pretreatment of cells with cycloheximide completely inhibited 
      insulin-stimulated ODC expression; actinomycin D partially inhibited this effect. 
      To determine the influence of the 5' untranslated region (5'UTR) of ODC mRNA on 
      insulin-regulated ODC expression, plasmids were constructed which contained 
      sequences from the 5'UTR of a rat ODC mRNA interposed between the ferritin 
      promoter and the coding region of the human growth hormone gene. These 
      constructions were then expressed transiently in HIR 3.5 cells. Insulin 
      stimulated a 2-4-fold change in growth hormone accumulation in the medium of 
      cells transiently expressing plasmids containing the entire 5'UTR of ODC mRNA or 
      just the 5'-most 115 bases, a G/C-rich conserved sequence predicted to form a 
      stem-loop structure and shown previously to be responsible for constitutive 
      inhibition of translation. There was a direct correlation between the extent of 
      insulin stimulation and the predicted secondary structure of the added 5'UTR 
      sequences. To determine whether this effect might be due to insulin activation of 
      initiation factors responsible for melting mRNA secondary structure, we examined 
      the effect of insulin on the phosphorylation states of two such factors, 
      eucaryotic initiation factors eIF-4B and eIF-4E. Insulin stimulated the 
      phosphorylation of both initiation factors; this stimulation was evident at 15 
      min and maximal by 60 min. These results suggest a potential general mechanism by 
      which insulin could preferentially stimulate translation of mRNAs whose 5'UTRs 
      exhibit significant secondary structure by activating initiation factors involved 
      in melting such secondary structures.
FAU - Manzella, J M
AU  - Manzella JM
AD  - Howard Hughes Medical Institute Laboratories, Duke University Medical Center, 
      Durham, North Carolina 27710.
FAU - Rychlik, W
AU  - Rychlik W
FAU - Rhoads, R E
AU  - Rhoads RE
FAU - Hershey, J W
AU  - Hershey JW
FAU - Blackshear, P J
AU  - Blackshear PJ
LA  - eng
GR  - 5T32 GM07184/GM/NIGMS NIH HHS/United States
GR  - GM20818/GM/NIGMS NIH HHS/United States
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PT  - Research Support, U.S. Gov't, P.H.S.
PL  - United States
TA  - J Biol Chem
JT  - The Journal of biological chemistry
JID - 2985121R
RN  - 0 (Eukaryotic Initiation Factor-4E)
RN  - 0 (Eukaryotic Initiation Factors)
RN  - 0 (Insulin)
RN  - 0 (Peptide Initiation Factors)
RN  - 0 (RNA, Messenger)
RN  - 0 (eIF-4B)
RN  - 1CC1JFE158 (Dactinomycin)
RN  - 98600C0908 (Cycloheximide)
RN  - EC 2.7.10.1 (Receptor, Insulin)
RN  - EC 4.1.1.17 (Ornithine Decarboxylase)
SB  - IM
MH  - Animals
MH  - Blotting, Northern
MH  - Cell Line
MH  - Cloning, Molecular
MH  - Cycloheximide/pharmacology
MH  - Dactinomycin/pharmacology
MH  - Dose-Response Relationship, Drug
MH  - Enzyme Induction
MH  - Eukaryotic Initiation Factor-4E
MH  - *Eukaryotic Initiation Factors
MH  - Humans
MH  - Insulin/*pharmacology
MH  - Mice
MH  - Nucleic Acid Conformation
MH  - Ornithine Decarboxylase/*biosynthesis/genetics
MH  - Peptide Initiation Factors/*metabolism
MH  - Phosphorylation
MH  - Protein Biosynthesis
MH  - RNA, Messenger/*chemistry/genetics
MH  - Receptor, Insulin/metabolism
EDAT- 1991/02/05 00:00
MHDA- 1991/02/05 00:01
CRDT- 1991/02/05 00:00
PHST- 1991/02/05 00:00 [pubmed]
PHST- 1991/02/05 00:01 [medline]
PHST- 1991/02/05 00:00 [entrez]
AID - S0021-9258(18)52255-9 [pii]
PST - ppublish
SO  - J Biol Chem. 1991 Feb 5;266(4):2383-9.