HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Kabat, D. Articles by Chappell, M. R. Search for Related Content PubMed PubMed Citation Articles by Kabat, D. Articles by Chappell, M. R. Social Bookmarking                      What's this?

JBC, Vol. 252, Issue 8, 2684-2690, Apr, 1977

Competition between globin messenger ribonucleic acids for a discriminating initiation factor

D. Kabat and M. R. Chappell

Translation of messenger ribonucleic acids for alpha- and beta-globin chains was analyzed in an mRNA-dependent fractionated protein-synthesizing system derived from rabbit reticulocytes. The alpha/beta 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 beta-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 beta-mRNA is 50 times larger than to alpha-mRNA. The concentration of discriminating factor-mRNA complex does not limit the overall rate of protein 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.
CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?

This article has been cited by other articles:

				D. Walsh, C. Perez, J. Notary, and I. Mohr Regulation of the Translation Initiation Factor eIF4F by Multiple Mechanisms in Human Cytomegalovirus-Infected Cells J. Virol., July 1, 2005; 79(13): 8057 - 8064. [Abstract] [Full Text] [PDF]