Competition between globin messenger ribonucleic acids for a discriminating initiation factor

David Kabat, M. R. Chappell

Research output: Contribution to journalArticle

57 Citations (Scopus)

Abstract

Translation of messenger ribonucleic acids for α- and β-globin chains was analyzed in an mRNA-dependent fractionated protein-synthesizing system derived from rabbit reticulocytes. The α/β chain synthesis ratio is highly dependent on the concentration of unfractionated globin mRNAs; the ratio is 1.5 at low mRNA concentration and declines to 0.03 at a high concentration. Several lines of evidence support the conclusion that this effect is caused by competitive binding of the messengers to an initiation factor which preferentially associates with the β-mRNA. Such a discriminating factor is present in the 0.5 M KCl wash fraction from ribosomes and it elutes from a diethylaminoethyl-cellulose column between 0.10 and 0.21 M KCl. Studies using purified preparations of initiation factors suggest that IF-M3 and IF-M4 may act synergistically to produce the activity of the discriminating initiation factor. Although the discriminating factor is required for translation of both messengers, its apparent binding constant to β-mRNA is 50 times larger than to α-mRNA. The concentration of discriminating factor mRNA complex does not limit the overall rate of synthesis in this cell-free system. Nevertheless, the relative effectiveness of different messengers is determined by the relative concentrations of their complexes with the discriminating factor.

Original languageEnglish (US)
Pages (from-to)2684-2690
Number of pages7
JournalJournal of Biological Chemistry
Volume252
Issue number8
StatePublished - 1977

Fingerprint

Peptide Initiation Factors
Globins
RNA
Messenger RNA
Competitive Binding
Cell-Free System
Reticulocytes
Ribosomes
Cellulose
Rabbits

ASJC Scopus subject areas

  • Biochemistry

Cite this

Competition between globin messenger ribonucleic acids for a discriminating initiation factor. / Kabat, David; Chappell, M. R.

In: Journal of Biological Chemistry, Vol. 252, No. 8, 1977, p. 2684-2690.

Research output: Contribution to journalArticle

@article{e954fa6cceff48278f609e47bb6bcebc,
title = "Competition between globin messenger ribonucleic acids for a discriminating initiation factor",
abstract = "Translation of messenger ribonucleic acids for α- and β-globin chains was analyzed in an mRNA-dependent fractionated protein-synthesizing system derived from rabbit reticulocytes. The α/β chain synthesis ratio is highly dependent on the concentration of unfractionated globin mRNAs; the ratio is 1.5 at low mRNA concentration and declines to 0.03 at a high concentration. Several lines of evidence support the conclusion that this effect is caused by competitive binding of the messengers to an initiation factor which preferentially associates with the β-mRNA. Such a discriminating factor is present in the 0.5 M KCl wash fraction from ribosomes and it elutes from a diethylaminoethyl-cellulose column between 0.10 and 0.21 M KCl. Studies using purified preparations of initiation factors suggest that IF-M3 and IF-M4 may act synergistically to produce the activity of the discriminating initiation factor. Although the discriminating factor is required for translation of both messengers, its apparent binding constant to β-mRNA is 50 times larger than to α-mRNA. The concentration of discriminating factor mRNA complex does not limit the overall rate of synthesis in this cell-free system. Nevertheless, the relative effectiveness of different messengers is determined by the relative concentrations of their complexes with the discriminating factor.",
author = "David Kabat and Chappell, {M. R.}",
year = "1977",
language = "English (US)",
volume = "252",
pages = "2684--2690",
journal = "Journal of Biological Chemistry",
issn = "0021-9258",
publisher = "American Society for Biochemistry and Molecular Biology Inc.",
number = "8",

}

TY - JOUR

T1 - Competition between globin messenger ribonucleic acids for a discriminating initiation factor

AU - Kabat, David

AU - Chappell, M. R.

PY - 1977

Y1 - 1977

N2 - Translation of messenger ribonucleic acids for α- and β-globin chains was analyzed in an mRNA-dependent fractionated protein-synthesizing system derived from rabbit reticulocytes. The α/β chain synthesis ratio is highly dependent on the concentration of unfractionated globin mRNAs; the ratio is 1.5 at low mRNA concentration and declines to 0.03 at a high concentration. Several lines of evidence support the conclusion that this effect is caused by competitive binding of the messengers to an initiation factor which preferentially associates with the β-mRNA. Such a discriminating factor is present in the 0.5 M KCl wash fraction from ribosomes and it elutes from a diethylaminoethyl-cellulose column between 0.10 and 0.21 M KCl. Studies using purified preparations of initiation factors suggest that IF-M3 and IF-M4 may act synergistically to produce the activity of the discriminating initiation factor. Although the discriminating factor is required for translation of both messengers, its apparent binding constant to β-mRNA is 50 times larger than to α-mRNA. The concentration of discriminating factor mRNA complex does not limit the overall rate of synthesis in this cell-free system. Nevertheless, the relative effectiveness of different messengers is determined by the relative concentrations of their complexes with the discriminating factor.

AB - Translation of messenger ribonucleic acids for α- and β-globin chains was analyzed in an mRNA-dependent fractionated protein-synthesizing system derived from rabbit reticulocytes. The α/β chain synthesis ratio is highly dependent on the concentration of unfractionated globin mRNAs; the ratio is 1.5 at low mRNA concentration and declines to 0.03 at a high concentration. Several lines of evidence support the conclusion that this effect is caused by competitive binding of the messengers to an initiation factor which preferentially associates with the β-mRNA. Such a discriminating factor is present in the 0.5 M KCl wash fraction from ribosomes and it elutes from a diethylaminoethyl-cellulose column between 0.10 and 0.21 M KCl. Studies using purified preparations of initiation factors suggest that IF-M3 and IF-M4 may act synergistically to produce the activity of the discriminating initiation factor. Although the discriminating factor is required for translation of both messengers, its apparent binding constant to β-mRNA is 50 times larger than to α-mRNA. The concentration of discriminating factor mRNA complex does not limit the overall rate of synthesis in this cell-free system. Nevertheless, the relative effectiveness of different messengers is determined by the relative concentrations of their complexes with the discriminating factor.

UR - http://www.scopus.com/inward/record.url?scp=0017393623&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0017393623&partnerID=8YFLogxK

M3 - Article

C2 - 856800

AN - SCOPUS:0017393623

VL - 252

SP - 2684

EP - 2690

JO - Journal of Biological Chemistry

JF - Journal of Biological Chemistry

SN - 0021-9258

IS - 8

ER -