Distinct cis-acting signals enhance 3' endpoint formation of CYC1 mRNA in the yeast Saccharomyces cerevisiae.

The cyc1-512 mutant of the yeast Saccharomyces cerevisiae contains a 38 bp deletion in the 3' untranslated region of the CYC1 gene, resulting in CYC1 mRNAs that are elongated, presumably labile, and reduced to 10% of the normal level. Analysis with S1 nuclease and a novel PCR procedure revealed that the low amount of cyc1-512 mRNA contained many discrete 3' termini at certain sites, ranging from the wild-type position to over 2000 nucleotides (nt) downstream. The cyc1-512 mRNA deficiency was completely or almost completely restored in eight intragenic revertants that contained six different single and multiple base-pair changes within a 300 bp region downstream from the translation terminator codon.

Two types of TATA elements for the CYC1 gene of the yeast Saccharomyces cerevisiae.

Functional TATA elements in the 5' untranslated region of the CYC1 gene in the yeast Saccharomyces cerevisiae have been defined by transcriptional analysis of site-directed mutations. Five sites previously suggested to contain functional TATA elements were altered individually and in all possible combinations. The results indicated that only two elements are required for transcription at the normal level and the normal start sites.

The specificities of yeast methionine aminopeptidase and acetylation of amino-terminal methionine in vivo. Processing of altered iso-1-cytochromes c created by oligonucleotide transformation.

The specificities of methionine aminopeptidase and amino-terminal acetylation in the yeast Saccharomyces cerevisiae were investigated in vivo by sequencing a series of altered iso-1-cytochrome c. Twenty iso-1-cytochromes c, each having a different penultimate residue in the sequence Met-Xaa-Phe-Leu-, were created by transforming yeast directly with synthetic oligonucleotides. The degree of methionine cleavage and amino-terminal acetylation was estimated from the levels of pertinent peptides separated by high performance liquid chromatography.

Totally anomalous pulmonary venous connection in an infant with tricuspid atresia.

The occurrence of tricuspid atresia in association with totally anomalous pulmonary venous connection is a rare one. This combination has been described in the literature only twice previously. Such a case is presented with special regard to the therapeutic options and the need for cardiac catheterization.

Chromosomal assignment of mutations by specific chromosome loss in the yeast Saccharomyces cerevisiae.

Yeast 2-microns plasmids were integrated near the centromere of a different chromosome in each of 16 cir0 mapping strains of Saccharomyces cerevisiae. The specific chromosomes containing the integrated 2-microns plasmid DNA were lost at a high frequency after crossing the cir0 strains to cir+ strains. A recessive mutation in a cir+ strain can then be easily assigned to its chromosome using this set of mapping strains, since the phenotype of the recessive mutation will be manifested only in diploids having the integrated 2-microns plasmid and the unmapped mutation on homologous chromosomes.

Medial adductor open reduction for congenital dislocation of the hip.

Twenty-two consecutive patients with 26 dislocated hips were evaluated for a mean of 7 years after open reduction through a medial adductor approach. Severin classification of grade I or II and center-edge angles greater than 20 degrees were present in 73% of hips and 88% of patients treated between the ages of 5 and 14 months. Avascular necrosis (AVN) with partial head involvement occurred in 15% of hips and correlated positively with increased age at surgery, but did not preclude a satisfactory Severin classification.

Nucleotide sequence of the COR region: a cluster of six genes in the yeast Saccharomyces cerevisiae.

We have determined the nucleotide (nt) sequence of the 7.5-kb COR segment that encompasses a cluster of six genes (CYC1, UTR1, UTR3, OSM1, tRNA(Gly) and RAD7) located on chromosome X of the yeast Saccharomyces cerevisiae. This sequence revealed five open reading frames and a tRNA gene which correspond in position, size and orientation to the transcripts previously identified by Barry et al.

Chromosomal rearrangements associated with morphological mutants provide a means for genetic variation of Candida albicans.

At frequencies as high as 1.4%, the pathogenic yeast Candida albicans spontaneously gave rise to morphological mutants exhibiting more than 20 different types of abnormal colonies; approximately two-thirds of the mutants were stable, while the other one-third were unstable and produced mixtures of different colonial forms at very high rates. Abnormal electrophoretic karyotypes were observed for all of the 14 mutants that were examined, indicating that they were associated with different types of single and multiple gross chromosomal rearrangements.

Isolation and characterization of omnipotent suppressors in the yeast Saccharomyces cerevisiae.

Approximately 290 omnipotent suppressors, which enhance translational misreading, were isolated in strains of the yeast Saccharomyces cerevisiae containing the psi+ extrachromosomal determinant. The suppressors could be assigned to 8 classes by their pattern of suppression of five nutritional markers. The suppressors were further distinguished by differences in growth on paromomycin medium, hypertonic medium, low temperatures (10 degrees), nonfermentable carbon sources, alpha-aminoadipic acid medium, and by their dominance and recessiveness.

Differential stability of two apo-isocytochromes c in the yeast Saccharomyces cerevisiae.

The yeast Saccharomyces cerevisiae contains two forms of cytochrome c, iso-1-cytochrome c and iso-2-cytochrome c, encoded by the genes CYC1 and CYC7, respectively. The amino acid sequences of these two isozymes are approximately 80% identical. Cyc3- mutants lack both holocytochromes c, because of a deficiency of cytochrome c heme lyase, the enzyme catalyzing covalent attachment of the heme group to apocytochrome c.

Expression and activity of a gene encoding rat cytochrome c in the yeast Saccharomyces cerevisiae.

A rat-processed pseudogene, which encodes normal rat cytochrome c, has been expressed in the yeast, Saccharomyces cerevisiae. The translated region of the chromosomal CYC1+ locus, which encodes yeast iso-1-cytochrome c, was replaced by the translated region of the gene encoding rat cytochrome c (CYC1-RAT), thus preserving the proper CYC1 transcription initiation and termination signals. Although the levels of transcription of the normal CYC1+ gene and the CYC1-RAT gene in yeast were equivalent, rat cytochrome c was produced at approx.

Transcription terminates near the poly(A) site in the CYC1 gene of the yeast Saccharomyces cerevisiae.

A 38-base-pair region required for normal CYC1 mRNA 3' end formation in Saccharomyces cerevisiae was shown to be necessary for the termination of transcription in vivo by examining the stability of CEN3 plasmids. CEN3 plasmids were stably maintained during vegetative growth, unless a GAL1 transcript impinged on the CEN3 region. Transcription from the GAL1 promoter was terminated, and plasmid stability was restored by the insertion of a fragment containing the 38-base-pair region of CYC1.

Identification and purification of natural killer cell stimulatory factor (NKSF), a cytokine with multiple biologic effects on human lymphocytes.

We have identified and purified a novel cytokine, NK cell stimulatory factor (NKSF), from the cell-free supernatant fluid of the phorbol diester-induced EBV-transformed human B lymphoblastoid cell line RPMI 8866. NKSF activity is mostly associated to a 70-kD anionic glycoprotein. The purified 70-kD protein, isolated from an SDS-PAGE gel, yields upon reduction two small species of molecular masses of 40 and 35 kD, suggesting that this cytokine is a heterodimer.

Identification and characterization of genes and mutants for an N-terminal acetyltransferase from yeast.

A gene from Saccharomyces cerevisiae has been mapped, cloned, sequenced and shown to encode a catalytic subunit of an N-terminal acetyltransferase. Regions of this gene, NAT1, and the chloramphenicol acetyltransferase genes of bacteria have limited but significant homology. A nat1 null mutant is viable but exhibits a variety of phenotypes, including reduced acetyltransferase activity, derepression of a silent mating type locus (HML) and failure to enter G0.

Supracondylar fractures of the humerus in children.

Thirty-five children were evaluated at a mean of 2 years, 3 months following treatment of supracondylar fractures of the humerus. Elbow motion, clinical carrying angle, and roentgenographic measurements including Baumann's angle, humeral-ulnar angle, and metaphyseal-diaphyseal angle were determined for both the normal and the involved extremities. The humeral-ulnar angle best correlated with the final clinical carrying angle, followed by Baumann's angle and the metaphyseal-diaphyseal angle.

Elucidation of the natural history of ventricular septal defects by serial Doppler color flow mapping studies.

Two-dimensional echocardiography has provided information to aid in the diagnosis and management of infants with ventricular septal defect, but its inability to resolve very small ventricular septal defects and problems with defining ventricular septal defect orifice size (because of overlying muscle or tricuspid tissue) have made it unsuitable as a standard for defining the natural history of ventricular septal defect. In this study, 114 serial two-dimensional Doppler color flow mapping studies were performed to define ventricular septal defect anatomy, location and color flow diameter as an indicator of shunt size in 66 patients (over a 40 month period). Twenty-five patients first studied at 6 months of age (mean age at most recent study 15.

Production of hematopoietic colony-stimulating factors by human natural killer cells.

We have analyzed the ability of highly purified preparations of human NK cells to produce CSF. NK cells, purified by negative selection from 10-d cultures of PBMC incubated with irradiated B-lymphoblastoid cell lines, were stimulated with rIL-2, FcR(CD16) ligands (particulate immune complexes or anti-CD16 antibodies bound to Sepharose), a combination of CD16 ligands and rIL-2, or the phorbol diester phorbol dibutyrate (PDBu) together with the Ca2+ ionophore A23187. Both rIL-2 and CD16 ligands induce accumulation of GM-CSF mRNA in NK cells and the combined effect of the two stimuli is synergistic.