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J R Rodriguez

Publications and source records attributed to J R Rodriguez.

45 records · Page 3Linked to original sources
PubMed1985

A quantitative analysis of the effects of 5' junction and TACTAAC box mutants and mutant combinations on yeast mRNA splicing.

We have introduced four point mutations into the 5' junction (GTATGT) and TACTAAC box of a yeast intron-containing gene coding for beta-galactosidase. To analyze quantitatively mutant combinations, we deliberately avoided nucleotides adjacent to the sites of cleavage (GTATGT) and lariat formation (TACTAAC) and chose positions with expected weak effects on splicing. All four mutants do not affect, or only marginally affect, gene expression. The levels of precursor RNA and intermediates indicate, however, that splicing efficiency is affected in all cases; the first stage of splicing, 5' cleavage and lariat formation, is reduced two to 15-fold in these four mutants. The mutants were combined to generate compensatory and noncompensatory double mutant combinations. No evidence for a specific base-pairing interaction between the 5' junction and TACTAAC box could be obtained. The results suggest that all conserved positions in the 5' junction and TACTAAC box play a role in splicing efficiency.

Base Sequence↗
PubMed1984

In vivo characterization of yeast mRNA processing intermediates.

Yeast mRNA introns contain a conserved sequence, TACTAAC, required for splicing. We previously identified a putative splicing intermediate characterized by a stop to reverse transcriptase at the TACTAAC box of the wild-type rp51A (ribosomal protein 51A gene) intron. We now show that this stop is due to a branch and occurs at the identical nucleotide in the actin intron TACTAAC box. We show further that the putative intermediate contains a complete intron and the 3' exon, but is missing the 5' exon. This RNA is largely in the form of a lariat. The lariat and the other putative splicing intermediates detected (two forms, of different molecular weights, of the excised intron and the free 5' exon) are compatible with the view that the cut at the 5' junction and lariat formation are early steps in yeast mRNA splicing and that substantial similarities exist between yeast and mammalian mRNA splicing.

Base Sequence↗
PubMed1983

The rna2 mutation of yeast affects the processing of actin mRNA as well as ribosomal protein mRNAs.

The temperature sensitive rna2 mutation of Saccharomyces cerevisiae causes a rapid and dramatic decrease in the abundance of most ribosomal protein mRNAs We and others have recently shown that the processing of ribosomal protein mRNAs is defective at the nonpermissive temperature, suggesting that inefficient mRNA processing might be responsible for the decline in ribosomal protein mRNA levels. Actin is the only known intron-containing non-ribosomal protein yeast nuclear gene We show here that the processing of actin mRNA is also defective at the nonpermissive temperature in rna2-containing strains. The observation supports the notion that all intron-containing genes are affected in a similar fashion by the rna2 mutation.

Actins↗
PubMed1976

[Cerebrovascular diseases of the "moyamoya" type].

The case of a 34-year-old caucasian male with subarachnoid hemorrahge is reported. The right carotid arteriogram shows the typical internal carotid artery occlusion at the syphon, whith an abnormal vascular network at the base of the brain; the right anterior and middle cerebral arteries fill from the vascular network and through meningocortical anastomoses; the right posterior communicating and cerebral arteries are tortuous and hypertrophic. The left carotid arteriogram shows hypertrophy of the common and internal carotid arteries; both anterior and middle cerebral arteries fill from this side; the anterior communicating artery is thick (foetal type) and a median anterior cerebral artery to the corpus callosum is present. It is the authors' view that the "moyamoya" disease is a congenital one, since the abnormal vascular network at the base of the brain would not be necessary, in this case, to preserve good collateral circulation to the right cerebral hemisphere. No other case with the typical findings of "moyamoya" disease on one side and hypertrophy of the carotid arteries on the other was found in the literature.

Adult↗