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M Carlson

Publications and source records attributed to M Carlson.

At least 19 recordsLinked to original sources
PubMed1992

Cloning of human and bovine homologs of SNF2/SWI2: a global activator of transcription in yeast S. cerevisiae.

We performed positional cloning of genes carried on yeast artificial chromosomes that span a human translocation breakpoint associated with a human disease and isolated by chance human and bovine genes with strong homology to the S. cerevisiae genes, SNF2/SWI2 and STH1, and the D. melanogaster gene brahma. We report here sequence analysis, expression data, and functional studies for this human SNF2-like gene (hSNF2L) and its bovine homolog (bovSNF2L). Despite strong homology at the amino acid level, hSNF2L is not capable of complementing the yeast mutations snf2 or sth1 in S. cerevisiae. Furthermore, in contrast to SNF2 itself, a fusion protein consisting of the DNA binding domain of LexA and hSNF2L did not transactivate a reporter gene downstream of LexA binding sites in a yeast expression system. The strong similarity between hSNF2L and these yeast and drosophila genes suggest that the mammalian genes are part of an evolutionarily conserved family that has been implicated as global activators of transcription in yeast and fruitflies but whose function in mammals remains unknown.

Adenosine Triphosphatases↗
PubMed1992

A protein kinase substrate identified by the two-hybrid system.

A genetic method, the two-hybrid system, was used to identify four genes encoding proteins that interact with the SNF1 protein kinase from yeast. One of the genes, SIP1, was independently isolated as a multicopy suppressor of defects caused by reduced SNF1 kinase activity, and genetic evidence supports its function in the SNF1 pathway. The SIP1 protein co-immunoprecipitated with SNF1 and was phosphorylated in vitro. Thus, the two-hybrid system, which is applicable to any cloned gene, can be used to detect physical interactions between protein kinases and functionally related substrate proteins.

AMP-Activated Protein Kinases↗
PubMed1992

Ssn6-Tup1 is a general repressor of transcription in yeast.

The homeodomain protein alpha 2 and the SRF-like protein Mcm1 are required to establish cell type in the yeast Saccharomyces cerevisiae. Together, these regulatory proteins recognize a specific DNA operator, marking a set of genes for transcriptional repression. In this paper, we show that occupancy of the operator by alpha 2-Mcm1 is not sufficient to bring about repression. Rather, repression is effected only when Ssn6 (a TPR protein) and Tup1 (a beta-transducin repeat protein) are also present in the cell. We show that Ssn6 represses transcription when brought to a promoter by a bacterial DNA-binding domain and that Tup1 is required for this repression. Based on these and other results, we propose that Ssn6-Tup1 is a general repressor of transcription in yeast, recruited to target promoters by a variety of sequence-specific DNA-binding proteins.

Immunoblotting↗
PubMed1992

Identification of RAD16, a yeast excision repair gene homologous to the recombinational repair gene RAD54 and to the SNF2 gene involved in transcriptional activation.

The RAD54 gene of Saccharomyces cerevisiae is involved in the recombinational repair of DNA damage. The predicted amino acid sequence of the RAD54 protein shows significant homologies with the yeast SNF2 protein, which is required for the transcriptional activation of a number of diversely regulated genes. These proteins are 31% identical in a 492-amino acid region that includes presumed nucleotide and Mg2+ binding sites. We noted previously that the SNF2 protein also shares homology with a partial open reading frame (ORF) that was reported with the sequence of an adjacent gene. This ORF also shares homology with the RAD54 protein. To test whether this ORF is involved in transcriptional activation or DNA repair, yeast strains deleted for part of it have been isolated. These strains do not show a Snf-like phenotype, but they are UV sensitive. This gene has been identified as RAD16, a gene involved in the excision repair of DNA damage. Analysis of the rad16 deletion mutations indicates that RAD16 encodes a non-essential function and is not absolutely required for excision repair. Outside the region of homology to RAD54 and SNF2, the predicted RAD16 protein contains a novel cysteine-rich motif that may bind zinc and that has been found recently in eleven other proteins, including the yeast RAD18 protein. The homologies between RAD16, RAD54 and SNF2 are also shared by several additional, recently isolated yeast and Drosophila genes.

Adenosine Triphosphatases↗
PubMed1992

Yeast SNF/SWI transcriptional activators and the SPT/SIN chromatin connection.

Genetic studies of many diversely regulated genes in the yeast Saccharomyces cerevisiae have identified two groups of genes with global functions in transcription. The first group comprises five SNF and SWI genes required for transcriptional activation. The other group, containing SPT and SIN genes, was identified by suppressor analysis and includes genes that encode histones. Recent evidence suggests that these SNF/SWI and SPT/SIN genes control transcription via effects on chromatin. SNF2/SWI2 sequence homologues have been identified in many organisms, suggesting that the SNF/SWI and SPT/SIN functions are conserved throughout eukaryotes.

Biological Evolution↗
PubMed1992

Degranulation of eosinophils from pollen-atopic patients with asthma is increased during pollen season.

The secretion of granule proteins from eosinophils and neutrophils was studied in isolated cells, obtained from 11 pollen-atopic patients with asthma, twice during and twice outside pollen season. Granulocytes were stimulated with serum-opsonized Sephadex particles, and the released amount of eosinophil cationic protein (ECP), eosinophil protein X (EPX), and myeloperoxidase (MPO) were measured by means of specific radioimmunoassay (RIA). Eosinophils from the pollen-atopic patients obtained during pollen season released significantly more (p less than 0.02) ECP and EPX than cells from the same patients obtained before pollen season. The released amount of ECP and EPX was correlated (r = 0.54; p less than 0.003) to the total pollen count. The release of MPO from neutrophils was only raised (p less than 0.01) at the end of the pollen season. Serum concentrations of ECP and EPX and blood eosinophil counts were significantly raised (p less than 0.002, p less than 0.001, and p less than 0.009, respectively) before pollen season and increased further at the end of the pollen season. There were no changes in lung function during pollen season and consequently no discernible relationships to eosinophil and neutrophil degranulation. We conclude that eosinophils and, to some extent, neutrophils from birch pollen-atopic subjects have an increased propensity to secrete their granule proteins during a pollen season. We suggest that these cells have been primed as a consequence of allergen exposure.

Adolescent↗
PubMed1992

Relationship of the cAMP-dependent protein kinase pathway to the SNF1 protein kinase and invertase expression in Saccharomyces cerevisiae.

The SNF1 protein kinase and the associated SNF4 protein are required for release of glucose repression in Saccharomyces cerevisiae. To identify functionally related proteins, we selected genes that in multicopy suppress the raffinose growth defect of snf4 mutants. Among the nine genes recovered were two genes from the cAMP-dependent protein kinase (cAPK) pathway, MSI1 and PDE2. Increased dosage of these genes partially compensates for defects in nutrient utilization and sporulation in snf1 and snf4 null mutants, but does not restore invertase expression. These results suggest that SNF1 and cAPK affect some of the same cellular responses to nutrients. To examine the role of the cAPK pathway in regulation of invertase, we assayed mutants in which the cAPK is not modulated by cAMP. Expression of invertase was regulated in response to glucose and was dependent on SNF1 function. Thus, a cAMP-responsive cAPK is dispensable for regulation of invertase.

Blotting, Northern↗
PubMed1992

N-terminal mutations modulate yeast SNF1 protein kinase function.

The SNF1 protein kinase is required for expression of glucose-repressed genes in response to glucose deprivation. The SNF4 protein is physically associated with SNF1 and positively affects the kinase activity. We report here the characterization of a dominant mutation, SNF1-G53R, that was isolated as a suppressor of the requirement for SNF4. The mutant SNF1-G53R protein is still responsive to SNF4 but has greatly elevated kinase activity in immune complex assays; in contrast, the activity is wild type in a protein blot assay. Deletion of the region N-terminal to the kinase domain (codons 5-52) reduces kinase activity in vitro, but the mutant SNF1-delta N kinase is still dependent on SNF4. The N terminus is not required for the regulatory response to glucose. In gel filtration chromatography, the SNF1, SNF1-G53R and SNF1-delta N protein showed different elution profiles, consistent with differential formation of high molecular weight complexes. Taken together, the results suggest that the N terminus positively affects the function of the SNF1 kinase and may be involved in interaction with a positive effector other than SNF4. We also showed that the conserved threonine residue 210 in subdomain VIII, which is a phosphorylation site in other kinases, is essential for SNF1 activity. Finally, we present evidence that when the C terminus is deleted, overexpression of the SNF1 kinase domain is deleterious to the cell.

AMP-Activated Protein Kinases↗
PubMed1992

Yeast SNF2/SWI2, SNF5, and SNF6 proteins function coordinately with the gene-specific transcriptional activators GAL4 and Bicoid.

The SNF2 (SWI2), SNF5, and SNF6 genes are required for transcription of many diversely regulated genes in Saccharomyces cerevisiae. Previously, we showed that SNF2, SNF5, and SNF6 function interdependently in transcriptional activation, possibly forming a heteromeric complex. Here, we present evidence that SNF6 has a more direct role in stimulating transcription than SNF2 and SNF5. The global effects of mutations in SNF2, SNF5, and SNF6 suggested that these SNF proteins may function coordinately with many gene-specific activators. We show that LexA-GAL4 and LexA-Bicoid fusion proteins are both dependent on SNF2, SNF5, and SNF6 for activation of target genes containing one or multiple lexA operators. The stringency of the requirement for the SNF proteins varies with the activator, the number of binding sites for the activator, and the target promoter. Thus, these SNF proteins appear to represent a class of intermediary proteins that facilitate transcriptional activation by gene-specific regulatory proteins.

Adenosine Triphosphatases↗
PubMed1992

An essential Saccharomyces cerevisiae gene homologous to SNF2 encodes a helicase-related protein in a new family.

The Saccharomyces cerevisiae SNF2 gene affects the expression of many diversely regulated genes and has been implicated in transcriptional activation. We report here the cloning and characterization of STH1, a gene that is homologous to SNF2. STH1 is essential for mitotic growth and is functionally distinct from SNF2. A bifunctional STH1-beta-galactosidase protein is located in the nucleus. The predicted 155,914-Da STH1 protein is 72% identical to SNF2 over 661 amino acids and 46% identical over another stretch of 66 amino acids. Both STH1 and SNF2 contain a putative nucleoside triphosphate-binding site and sequences resembling the consensus helicase motifs. The large region of homology shared by STH1 and SNF2 is conserved among other eukaryotic proteins, and STH1 and SNF2 appear to define a novel family of proteins related to helicases.

Adenosine Triphosphatases↗
PubMed1992

The role of occupational therapy in the management of depression.

This document was prepared at the request of the Depression Panel of the Office of the Forum for Quality and Effectiveness in Health Care within the Agency for Health Care Policy and Research, an agency of the U.S. Public Health Service. The panel was charged to develop clinical practice guidelines for the management of depression to be used by general medical and family medicine practitioners in primary care settings. The form of the panel's questions shaped the introductory portion of the document. After receiving the questions posed by the panel (which are stated later in this document), it was necessary to define the context of the use of occupation and occupational therapy to broaden the panel's understanding of these terms.

Adaptation, Psychological↗
PubMed1991

Identification and characterization of the familial adenomatous polyposis coli gene.

DNA from 61 unrelated patients with adenomatous polyposis coli (APC) was examined for mutations in three genes (DP1, SRP19, and DP2.5) located within a 100 kb region deleted in two of the patients. The intron-exon boundary sequences were defined for each of these genes, and single-strand conformation polymorphism analysis of exons from DP2.5 identified four mutations specific to APC patients. Each of two aberrant alleles contained a base substitution changing an amino acid to a stop codon in the predicted peptide; the other mutations were small deletions leading to frameshifts. Analysis of DNA from parents of one of these patients showed that his 2 bp deletion is a new mutation; furthermore, the mutation was transmitted to two of his children. These data have established that DP2.5 is the APC gene.

Adenomatous Polyposis Coli↗
PubMed1991

Identification of deletion mutations and three new genes at the familial polyposis locus.

Small (100-260 kb), nested deletions were characterized in DNA from two unrelated patients with familial adenomatous polyposis coli (APC). Three candidate genes located within the deleted region were ascertained and a previous candidate gene, MCC, was shown to be located outside the deleted region. One of the new genes contained sequence identical to SRP19, the gene coding for the 19 kd component of the ribosomal signal recognition particle. The second, provisionally designated DP1 (deleted in polyposis 1), was found to be transcribed in the same orientation as MCC. Two other cDNAs, DP2 and DP3, were found to overlap, forming a single gene, DP2.5, that is transcribed in the same orientation as SRP19.

Adenomatous Polyposis Coli↗
PubMed1991

Functional interdependence of the yeast SNF2, SNF5, and SNF6 proteins in transcriptional activation.

The SNF2, SNF5, and SNF6 genes of Saccharomyces cerevisiae are required for expression of a variety of differently regulated genes. Previous evidence implicated the SNF5 protein in transcriptional activation, and a DNA-bound LexA-SNF5 fusion protein was shown to activate expression of a nearby promoter. Here, we examine the functional relationship of the SNF2, SNF5, and SNF6 proteins. Activation by DNA-bound LexA-SNF5 fusion protein was greatly reduced in snf2 and snf6 mutants, indicating that activation by LexA-SNF5 requires SNF2 and SNF6 function. An spt6 mutation, which suppresses transcriptional defects caused by snf2, restored activation by LexA-SNF5 in a snf2 mutant. The SNF2 gene was sequenced and encodes a 194-kDa protein that is targeted to the nucleus. DNA-bound LexA-SNF2 fusion protein also activated transcription, dependent on SNF5 and SNF6. These findings suggest that SNF2, SNF5, and SNF6 function interdependently in transcriptional activation, possibly forming a heteromeric complex.

Adenosine Triphosphatases↗
PubMed1991

Nitrate-nitrite levels in commercially processed and home processed beets and spinach.

Nitrate and nitrite content of commercially processed and home processed beets and spinach samples were analyzed using specific ion electrode and colorimetric methods. The home processed beets were found to be significantly higher in nitrate content than the commercially processed beets. This difference was attributed to differences in processing methods. Pickled and Harvard beets contained significantly lower amounts of nitrate/nitrite on a dry weight basis than the other types of processed beets, evidently due to the diluting effect of added sucrose. Home frozen spinach showed a trend toward lower nitrate content than commercially frozen spinach, although the difference was not significant. Length of storage of home processed beets and spinach did not appear to affect nitrate or nitrite content.

Colorimetry↗
PubMed1991

Secretion of granule proteins from eosinophils and neutrophils is increased in asthma.

The activity of eosinophil and neutrophil granulocytes with respect to secretion of granule proteins was studied in 30 patients with asthma and with varying severity of their disease. Granulocytes were stimulated with serum-opsonized Sephadex particles, and the released amount of eosinophil cationic protein (ECP), eosinophil protein X (EPX), and myeloperoxidase was measured by means of specific radioimmunoassays. Eosinophils from patients with asthma released significantly more (p less than 0.001) ECP and EPX after 20 minutes of incubation than cells from control subjects without asthma. The release of myeloperoxidase from neutrophils was also somewhat higher (p less than 0.03). The serum concentrations of ECP and EPX were also significantly increased (p less than 0.001) in the group with asthma. No significant relationships were found between clinical variables and the secretory activity of either eosinophils or neutrophils. We conclude that eosinophils and, to some extent, neutrophils from subjects with asthma have an increased propensity to release their granule proteins, which we suggest is a consequence of priming of these cells.

Adult↗