Poly(A)-containing RNA fromPetroselinum hortense:Isolation, properties and messenger functionin vitro
✍ Scribed by H. Ragg; J. Schroeder; K. Hahlbrock
- Publisher
- Springer
- Year
- 1975
- Tongue
- English
- Weight
- 407 KB
- Volume
- 2
- Category
- Article
- ISSN
- 0301-4851
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✦ Synopsis
Cell suspension cultures from parsley (Petroselinum hortense Hoffm.) were labelled in vivo with [2 -3 H] adenosine. The RNA isolated from the ribosomal pellet was fractionated on an oligo(dT)-cellulose column. Approximately 1.5% of the RNA, representing about 15% of the total radioactivity, was retained at high salt concentrations and eluted at low ionic strength. As determined by two independent methods, this fraction contained poly(A) segments with an average length of about 80 nucleotides. It was active as template in a cell-free system from wheat germ, directing the synthesis of peptides ranging in molecular weight from about 4000-40000 daltons.
I. INTRODUCTION
In the last few years it has been established that, with the exception of histone mRNA, the mRNAs of many types of eucaryotic cells contain segments of poly(A) [ 1 ]. This finding has often been tacitly extended to the mRNAs of higher plants, since they are also eucaryotic organisms. There is, however, only a relatively small body of information supporting this conclusion. It has been known for years that plants contain RNA fractions with relatively large amounts of adenine [2-4], and enzymes synthesizing poly(A) have been described [5,6]. Poly(A)-containing RNA fractions have been isolated from several plant tissues, but in most cases their template activity in vitro was not investigated [7][8][9][10][11][12][13][14]. RNA fractions with template activity in vitro have been purified, but often they were obtained with methods which were not selective for poly(A)-contairting RNA [15][16][17]. Template activity of specifically poly(A)containing RNA from plants has been rarely documented [ 13,14]. In this report we describe the isolation of a rapidly labelled, poly(A)-containing RNA fraction from parsley cell suspension cultures and demonstrate that this RNA directs the synthesis of proteins in a cell-free system from wheat germ.
II. MATERIALS AND METHODS
1. Materials
[2) H] Adenosine (13 Ci mmole-1 ) and L-[aSS] methionine (90-130 Ci mmole-1 ) were