Wheat Embryo Ribonucleates. II. 3′-Hydroxyl Termini of the Satellite, 18 S, and 26 S Ribosomal Ribonucleates

1973 ◽  
Vol 51 (8) ◽  
pp. 1195-1202 ◽  
Author(s):  
A. A. Azad ◽  
B. G. Lane
Keyword(s):  
Ribosomal Rna ◽  
Source Material ◽  
Satellite Rna ◽  
Wheat Embryo ◽  
Hydroxyl Termini

(1) Terminal labelling with (3H)-borohydride has been used as a means of examining the 3′-hydroxyl termini in wheat embryo RNA.(2) The principal 3′-hydroxyl termini in the "satellite," 18 S, and 26 S components of wheat-embryo ribosomal RNA have been found to be cytidine, guanosine, and uridine, respectively.(3) The occurrence of 3′-hydroxyl terminal cytidine, in satellite RNA, and 3′-hydroxyl terminal guanosine, in 18 S RNA, has never been observed for the corresponding ribosomal ribonucleates from any other source material. The possible significance of this "irregularity" is a subject of discussion.

Wheat embryo ribonucleates. X. Metabolism of 3′-hydroxyl termini in the conserved mRNA and tRNA of imbibing wheat embryos

1978 ◽  
Vol 56 (3) ◽  
pp. 197-202 ◽  
Author(s):  
T. D. Kennedy ◽  
B. G. Lane
Keyword(s):  
Ribosomal Rna ◽  
Messenger Rna ◽  
Insoluble Fraction ◽  
Wheat Embryo ◽  
Selective Labelling ◽  
Wheat Embryos ◽  
Chain Lengths ◽  
Hydroxyl Termini ◽  
Terminal Poly ◽  
Mass Component

There are conserved complements of ribosomal RNA (rRNA), transfer RNA (tRNA), and messenger RNA (mRNA) in dry wheat embryos. Although early labelling of RNA is largely directed toward the synthesis of complete molecules of nascent rRNA and mRNA, there is also selective labelling at 3′-hydroxyl termini in conserved polynucleotides when dry wheat embryos are subjected to short-term (0.5 h) imbibition in a medium that contains tritium-labelled adenosine, guanosine, cytidine, and uridine. Conserved tRNA is the principal mass component in NaCl-soluble RNA (sRNA) and most of the 'rapid labelling' of sRNA (rl-sRNA) is a result of labelling at 3′-hydroxyl termini in conserved tRNA. By contrast, although conserved rRNA is the principal mass component in NaCl-insoluble RNA (iRNA), most of the labelled 3′-hydroxyl termini in 'rapidly labelled' iRNA (rl-iRNA) do not appear to derive from rRNA. Although about 10% of the labelled 3′-hydroxyl termini in rl-iRNA originates in conserved poly(A)-rich mRNA, the available evidence leads to the conclusion that most of the labelled 3′-hydroxyl termini in rl-iRNA originates in an unusual NaCl-insoluble fraction of conserved tRNA. During the course of extended imbibition, between 0.5 and 5 h, there are characteristic changes in the chain lengths and labelling patterns for 3′-hydroxyl terminal poly(A) sequences in mRNA. Analytical and physiological implications of these data are subjects of discussion.

scholarly journals Genetic mapping of the compatibility between a lily isolate of Cucumber mosaic virus and a satellite RNA

2005 ◽  
Vol 86 (8) ◽  
pp. 2359-2369 ◽  
Author(s):  
Naoya Yamaguchi ◽  
Yuko Seshimo ◽  
Eri Yoshimoto ◽  
Hong Il Ahn ◽  
Ki Hyun Ryu ◽  
...  
Keyword(s):  
Amino Acid ◽  
Genetic Mapping ◽  
Cucumber Mosaic Virus ◽  
Mosaic Virus ◽  
Source Material ◽  
Pronounced Effect ◽  
Amino Acid Residues ◽  
Satellite Rna ◽  
Rna Sequence ◽  
Ordinary Strain

Five isolates of Cucumber mosaic virus (CMV) from Lilium sp. (lily), which were isolated from specimens in Japan, Korea and Taiwan, were unable to support satellite RNA (satRNA) accumulation. In order to map the CMV sequences that are involved in satRNA support, HL-CMV (Japanese lily isolate), Y-CMV (ordinary strain) and Y-satellite RNA (Y-sat) were used as the source material. The pseudorecombinants between Y-CMV and HL-CMV revealed that RNA1 was essential for satRNA replication in lily. The results of chimeric constructs and various mutations showed that two amino acid residues (at positions 876 and 891) in the 1a protein were the determinants for the inability of HL-CMV to support a satRNA. Specifically, Thr at position 876 had a more pronounced effect than Met at position 891. Specific changes in RNA sequence were also detected in the 3′ terminus of Y-sat and these particular alterations allowed it to be supported by HL-CMV. It is believed that, through evolution, the adaptation of CMV to lily resulted in the introduction of amino acid changes in the 1a protein, changes that coincidentally affected the ability of lily CMV to support satRNAs.

Hypermodified alkali-stable dinucleotide sequences in each of the high-molecular-weight (26S and 18S) ribosomal RNA species of wheat

1977 ◽  
Vol 55 (5) ◽  
pp. 582-586 ◽  
Author(s):  
M. W. Gray ◽  
R. S. Cunningham
Keyword(s):  
Molecular Weight ◽  
Ribosomal Rna ◽  
18S Rrna ◽  
28S Rrna ◽  
Animal Cells ◽  
Wheat Embryo ◽  
Rrna Species ◽  
Wheat Embryos ◽  
The Individual ◽  
26S Rrna

Two hypermodified, alkali-stable dinucleotide sequences, each containing abase modification in addition to sugar methylation, are known to be present in wheat embryo 26S + 18S rRNA (Gray, M. W. (1974) Biochemistry 13, 5453–5463). Quantitative analysis of unfractionated 26S + 18S rRNA had suggested that each of these sequences (Cm-ψp and ψm-Ap, where Cm = O2′-methylcytidine and ψm = O2′-methylpseudouridine) was present in either the 18S or the 26S rRNA species, but not in both, at a frequency of not more than once per chain. In the study reported here, the individual 32P-labeled 18S and 26S rRNA species were isolated from viable wheat embryos germinated in the presence of [32P]orthophosphate. From analyses of phosphodiesterase and alkaline hydrolysates of the separated [32P]RNAs, we conclude that ψm-Ap is confined to wheat cytosol 18S rRNA, whereas Cm-ψp is localized in wheat cytosol 26S rRNA. The presence of ψm in the 18S rRNA of wheat stands in contrast with the situation in animal cells, where this hypermodified nucleoside is located in the 28S rRNA (Khan, M. S. N. &Maden, B. E. H. (1976) J. Mol. Biol. 101, 235–254)

The chain termini of polynucleotides formed by limited enzymic fragmentation of wheat embryo ribosomal RNA. Part 1. Studies of snake venom phosphodiesterase

1968 ◽  
Vol 46 (1) ◽  
pp. 81-92 ◽  
Author(s):  
B. D. McLennan ◽  
B. G. Lane
Keyword(s):  
Snake Venom ◽  
Ribosomal Rna ◽  
Sedimentation Rate ◽  
Sharp Decrease ◽  
Degree Of Polymerization ◽  
Wheat Embryo ◽  
Snake Venom Phosphodiesterase ◽  
Endonucleolytic Cleavage ◽  
Limited Degree ◽  
Hydrolysis Of

Snake venom phosphodiesterase induces about fifteen exonucleolytic cleavages for each endonucleolytic cleavage during the first hour of hydrolysis of wheat embryo ribosomal RNA, under the conditions of hydrolysis used in this present investigation. The polynucleotide chains in the ribosomal RNA preparation have an average degree of polymerization in the neighborhood of 1300 nucleotide residues, and there is a mean of between 5 and 10 endonucleolytic breaks per chain during this first hour of phosphodiesterase-induced hydrolysis. The cleavages occur widely throughout most of the polynucleotide chains in the ribosomal RNA preparation, as judged by the sharp decrease in mean sedimentation rate which accompanies a limited degree (about 10%) of exonucleolysis of the RNA. Studies of phosphodiesterase-induced endonucleolysis of wheat embryo soluble RNA are reported, but because of the much lower initial degree of polymerization (about 80 nucleotide residues per polynucleotide chain), the results of endonucleolysis are less pronounced in terms of the proportional increment in chain termini and the proportional decrease of mean sedimentation rate. The endonucleolysis of RNA is discussed in terms of the minor nucleotide components in both ribosomal and soluble RNA, and particular reference is made to pseudouridylate which has been found in relatively high proportion among the chain termini after limited hydrolysis with venom phosphodiesterase.Purified venom phosphodiesterase preparations, devoid of ribonuclease or 5′-nucleotidase contamination, were found to convert nucleoside 2′(3′),5′-diphosphates to 5′-nucleotides under conditions which had virtually no effect on nucleoside 3′-phosphates or nucleoside 5′-phosphates. The possibility that this reaction may be catalyzed by the venom phosphodiesterase itself is discussed.

Wheat embryo ribonucleates. VIII. The presence of 7-methylguanosine 'cap structures' in the RNA of imbibing wheat embryos

1977 ◽  
Vol 55 (8) ◽  
pp. 819-824 ◽  
Author(s):  
M. S. Saini ◽  
B. G. Lane
Keyword(s):  
Ribosomal Rna ◽  
Messenger Rna ◽  
Large Fraction ◽  
Deae Cellulose ◽  
Careful Analysis ◽  
Significant Fraction ◽  
Unbound Fraction ◽  
Wheat Embryo ◽  
Wheat Embryos ◽  
The Subject

1. By imbibing wheat embryos in media that contain methyl-labelled methionine, it is possible to label both terminal and nonterminal 7-methylguanosine constituents in NaCl-insoluble (2.5 M, 0 °C) RNA (iRNA).2. Most of the 7-[Me-14C]methylguanosine in wheat embryo i[Me-14C]RNA is present in nonterminal positions of polynucleotide chains, probably in ribosomal RNA.3. By passage through a column of oligo-dT-cellulose, it is possible to show that most of the 7-[Me-3H]methylguanosine in a 'bound' fraction of i[Me-3H]RNA from imbibing wheat embryos is present in terminal 'cap' structures, probably in messenger RNA.4. Although most of the 7-[Me-3H]methylguanosine in the 'unbound' (to oligo-dT-cellulose) fraction of i[Me-3H]RNA was present in nonterminal positions, there was also a highly significant fraction of 7-[Me-3H]methylguanosine in terminal 'cap' structures. Although it will be a subject of continued investigation, possible reasons why a large fraction of the total 7-[Me-3H]-methylguanosine was present in the 'unbound' fraction, in this present study, are a subject of discussion.5. Careful analysis failed to reveal the presence of any N6,O2′-di[Me-3H]methyladenosine in the 'unbound' fraction of i[Me-3H]RNA.6. Factors that might influence the binding of 'cap' oligonucleotides to DEAE-cellulose are the subject of a brief discussion.

scholarly journals Wheat embryo mitochondrial 18S ribosomal RNA: evidence for its prokaryotic nature

1977 ◽  
Vol 4 (3) ◽  
pp. 663-671 ◽  
Author(s):  
L. Bonen ◽  
R.S. Cunningham ◽  
M.W. Gray ◽  
W.F. Doolittle
Keyword(s):  
Ribosomal Rna ◽  
Wheat Embryo ◽  
18S Ribosomal Rna

Wheat embryo ribonucleates. IX. Generation of N2-dimethylguanylate when bulk wheat embryo tRNA is used as substrate for wheat embryo S-adenosylmethionine-tRNA methyltransferases, in vitro

1977 ◽  
Vol 55 (10) ◽  
pp. 1039-1048
Author(s):  
T. D. Kennedy ◽  
T. C. Kwong ◽  
B. G. Lane
Keyword(s):  
Large Fraction ◽  
Convincing Evidence ◽  
Source Material ◽  
Physiological Significance ◽  
Methyl Groups ◽  
In Vitro Experiments ◽  
Wheat Embryo ◽  
Experimental Findings

Although the cellular ribonucleates in normally growing cells are virtually saturated with respect to their customary complement of methyl substituents, it has often been reported that 'marginal' levels of (homologous) methylation can be detected when ribonucleates and enzymes from the same source material are incubated, together with S-adenosylmethionine, in vitro. Experiments were designed to acquire new insights that might be useful for circumscribing the number of possible interpretations that could be advanced to account for the introduction of 'supernumerary' methyl groups during (homologous) methylation of wheat RNA by wheat enzymes, in vitro. For a large fraction of the supernumerary methyl groups that can be introduced into wheat RNA, in vitro, it was not possible to adduce convincing evidence in support of the view that any appreciable quantity of methyl groups is ever introduced at these same sites, in vivo. The possibility that these supernumerary methyl groups might have transient existence, in vivo, and the potential physiological significance of any such occurrence are dealt with as part of a more general discussion of the experimental findings.

Wheat embryo ribonucleates. VI. Comparison of the 3′-hydroxyl termini in 'rapidly labelled' RNA from metabolizing wheat embryos with the corresponding termini in ribosomal RNA from differentiating embryos of wheat, barley, corn and pea

1976 ◽  
Vol 54 (3) ◽  
pp. 261-271 ◽  
Author(s):  
K. M. Oakden ◽  
B. G. Lane
Keyword(s):  
18S Rrna ◽  
Short Term ◽  
Plant Materials ◽  
Wheat Embryo ◽  
Pea Seedlings ◽  
Wheat Embryos ◽  
26S Rrna ◽  
Hydroxyl Termini ◽  
End Group

The NaCl-insoluble (2.5 M, 0 °C) fraction of wheat embryo RNA (iRNA) can be labelled when wheat embryos are subjected to either short-term (0.5 h) or long-term (24 h) imbibition in a medium that contains tritium-labelled adenosine, guanosine, cytidine and uridine. Electrophoretic analyses reveal that, after short-term labelling, there is a broadly heterodisperse distribution of radioactivity in 'rapidly labelled' i[3H]RNA, but after long-term labelling, there is an essentially trimodal distribution of radioactivity in i[3H]RNA. End-group analyses reveal that, after short-term labelling, adenosine is the principal 3′-hydroxyl terminus in all centrifugal subfractions of 'rapidly labelled' i[3H]RNA, whereas cytidine (in 5.8S rRNA), guanosine (in 18S rRNA) and uridine (in 26S rRNA) are the principal 3′-hydroxyl termini in centrifugal subfractions of wheat embryo i[3H]RNA. Guanosine is also the principal 3′-hydroxyl terminus in the 18S rRNA of differentiating embryos excized from both monocotyledonous (wheat, barley, corn) and dicotyledonous (pea) seedlings. The implications that the end-group measurements may have for current views about the possible biochemical involvements of 3′-hydroxyl terminal sequences in both mRNA and 18S rRNA are subjects of discussion. Incidental to the principal investigation, an existing technique for analyzing the RNA contents of cellular materials has been appropriately modified to circumvent interference from uv-absorbing pigments, which, when present, prevent application of the method to plant materials.

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