Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P01034 (cystatin C)
 3,397 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Continuing our investigation of the tRNA genes and gene products in Mycoplasma mycoides, we report the sequence of the gene for tRNALeu (CAA) as well as partial primary structures of the following tRNAs: Leu (CAA), Leu (UAG), Arg (UCU), Thr (AGU) and Ile (CAU). It is suggested that in M. mycoides, at least some of the family codon boxes are read by only one tRNA each, using an unconventional method which does not discriminate between the nucleotides in the third codon position. M. mycoides is the first free-living organism known to use an unconventional method of this kind.
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PMID:Unconventional codon reading by Mycoplasma mycoides tRNAs as revealed by partial sequence analysis. 247 10

The molecular mechanism of human intestinal apolipoprotein (apo) B-48 synthesis has been elucidated by a combination of sequencing of cloned complementary DNAs and RNase cleavage analysis of RNA heteroduplex. All intestinal cDNA clones contained a single C to T base substitution in the codon CAA encoding Gln2153 in apoB-100 cDNA, resulting in a translational stop. One of the our intestinal apoB cDNA clones was polyadenylated 106 bases downstream from the stop codon, possibly producing a 7-kb apoB message in the intestine. RNase cleavage analysis of the RNA heteroduplex between hepatic or intestinal RNA and apoB cDNA-directed anti-sense RNA showed that this single C to U substitution may occur in most of intestinal apoB mRNA. These results suggested that human apoB-48 is mostly produced by apoB mRNA with an in-frame stop codon in the intestine.
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PMID:Single base substitution between human intestinal and hepatic apolipoprotein B mRNA detected by ribonuclease cleavage analysis. 247 84

Apolipoprotein (apo) B occurs in two forms, apoB100 (512 kDa) and apoB48 (240 kDa); both are derived from the same gene. A novel mechanism involving editing of the apoB mRNA causes the formation of apoB48; the first base of codon 2153 is changed from cytosine to uracil, converting a glutamine codon to a premature stop codon. To identify the apoB mRNA sequence elements recognized by the apoB mRNA editing mechanism, two apoB cDNA fragments (354 and 63 base pairs) with codon 2153 near their centers were inserted into a high expression vector of another secreted apolipoprotein, apoE. The resulting vectors, pHEB-354 and -63, were transfected into Chinese hamster ovary cells, HepG2 cells, and apoB48-producing CaCo-2 cells. The secreted chimeric apolipoproteins (apoEB354 and apoEB63) were analyzed for premature truncation, and the mRNA was analyzed for the presence of an edited base. The pHEB-354 construct produced a truncated protein only in CaCo-2 cells, whereas pHEB-63 produced no truncated protein in any of the three cell types. The mRNA was converted to cDNA and amplified by the polymerase chain reaction technique. Differential hybridization of the polymerase chain reaction products with CAA (Gln) and TAA (Stop) specific probes detected an edited base only in cDNA from CaCo-2 cells transfected with pHEB-354, in agreement with the protein analysis. We conclude that the nucleotide sequence of the apoB cDNA insert in pHEB-354 contains sufficient information to be edited in CaCo-2 cells. In these cells, a cryptic polyadenylation site was activated in the edited pHEB-354 mRNA. As a result, CaCo-2 cells transfected with pHEB-354 produced a short, edited pHEB-354 mRNA and a long, unedited pHEB-354 mRNA. Chinese hamster ovary cells transfected with pHEB-354 or CaCo-2 cells transfected with pHEB-63 produced only a full length transcript. Amplification of the pHEB-354 cDNA using 3'-primers upstream and downstream of the poly(A) addition site and hybridization with the TAA probe confirmed these results. This unusual mRNA editing apparently occurs before polyadenylation, probably in the nucleus.
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PMID:Apolipoprotein B48 RNA editing in chimeric apolipoprotein EB mRNA. 247 6

The presence of gene lesions in coagulation factor VIII (FVIII) gene was investigated in 70 Italian patients severely affected by haemophilia A. cDNA probes specific for exons 14-26 of the FVIII gene were used. In two related patients a gene deletion removes exon 26, a gene lesion similar to that described previously in a British haemophiliac. In exon 24 a C to T transition in the reverse complement strand causes a missense mutation in the coding strand (CGA----CAA, 2209 Arg----Gln). The mutation is located in a very conserved FVIII homology region and severely reduces FVIII activity. By restriction analysis and hybridizations with oligonucleotide probes this gene alteration was found in two unrelated haemophiliacs and in their relatives.
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PMID:A recurrent missense mutation (Arg----Gln) and a partial deletion in factor VIII gene causing severe haemophilia A. 249 3

White-crowned Sparrows (WCS) were given free access to pairs of semisynthetic diets that were either adequate or subadequate (25% of requirement) in valine or lysine. Within 2 to 4 days WCS chose a ratio of the paired diets that allowed them to maintain body mass or restore any losses quickly. On the initial choice days the birds transiently reduced total daily food intake (TDFI) roughly in proportion to their intake of the subadequate diet. The initial decrease of TDFI was greater and the latency in choosing an effective ratio of the paired diets was 2-3 days longer with valine than with lysine diets in well-nourished test birds. In malnourished birds fed only the subadequate test diet for 3 days, valine-deficient birds increased TDFI and body mass more promptly than did lysine-deficient birds when offered a choice of adequate and subadequate diets. The form of the test amino acid (CAA = crystalline, PB = protein-bound) had little effect on choice behavior, but sudden transfer of WCS from a PB acclimation diet to test diets with a large total CAA concentration increased the latency of effective choice by 2-3 days. A brief acclimation (2-3 days) to a CAA diet precludes any bias between nutritionally equivalent CAA and PB diets. The small differences in choice dynamics between valine and lysine and between dietary forms may help to identify mechanisms involved in food choice but are probably ecologically insignificant to free-living WCS. These birds are very adept at selecting diets that satisfy their amino acid requirements.
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PMID:Sparrows discriminate between diets differing in valine or lysine concentrations. 250 86

Three okadaic acid class tumor promoters, okadaic acid, dinophysistoxin-1, and calyculin A, have potent tumor-promoting activity in two-stage carcinogenesis experiments on mouse skin. DNA isolated from tumors induced by 7,12-dimethylbenz[a]anthracene (DMBA) and each of these tumor promoters revealed the same mutation at the second nucleotide of codon 61 (CAA----CTA) in the c-Ha-ras gene, determined by the polymerase chain reaction procedure and DNA sequencing. Three potent 12-O-tetradecanoylphorbol-13-acetate (TPA)-type tumor promoters, TPA, teleocidin, and aplysiatoxin, showed the same effects. These results provide strong evidence that this mutation in the c-Ha-ras gene is due to a direct effect of DMBA rather than a selective effect of specific tumor promoters.
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PMID:Codon 61 mutations in the c-Harvey-ras gene in mouse skin tumors induced by 7,12-dimethylbenz[a]anthracene plus okadaic acid class tumor promoters. 250 60

A Dictyostelium discoideum repetitive element composed of long repeats of the codon (AAC) is found in developmentally regulated transcripts. The concentration of (AAC) sequences is low in mRNA from dormant spores and growing cells and increases markedly during spore germination and multicellular development. The sequence hybridizes to many different sized Dictyostelium DNA restriction fragments indicating that it is scattered throughout the genome. Four cDNA clones isolated contain (AAC) sequences in the deduced coding region. Interestingly, the (AAC)-rich sequences are present in all three reading frames in the deduced proteins, i.e., AAC (asparagine), ACA (threonine) and CAA (glutamine). Three of the clones contain only one of these in-frame so that the individual proteins carry either asparagine, threonine, or glutamine clusters, not mixtures. However, one clone is both glutamine- and asparagine-rich. The (AAC) portion of the transcripts are reiterated 300 times in the haploid genome while the other portions of the cDNAs represent single copy genes, whose sequences show no similarity other than the (AAC) repeats. The repeated sequence is similar to the opa or M sequence found in Drosophila melanogaster notch and homeo box genes and in fly developmentally regulated transcripts. The transcripts are present on polysomes suggesting that they are translated. Although the function of these repeats is unknown, long amino acid repeats are a characteristic feature of extracellular proteins of lower eukaryotes.
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PMID:Nucleotide sequences of Dictyostelium discoideum developmentally regulated cDNAs rich in (AAC) imply proteins that contain clusters of asparagine, glutamine, or threonine. 251 21

In this work 26 patients with schistosomal specific nephropathy were randomly distributed among three groups. Group I cases were given anti-schistosomal drugs (oxamniquine and praziquantel), group II cases were given anti-schistosomal drugs plus prednisolone, and group III cases were given anti-schistosomal drugs plus cyclosporine. The schistosomal specificity of kidney lesions was assessed by detecting the schistosomal specific antigens (CAA and CCA) and antibodies deposited in the renal glomeruli of these patients. Patients who had another etiologic cause which may explain their kidney disease were not admitted to this study. After initiation of the treatment, patients were followed up every other week in the outpatient clinic for 12 months. Follow-up showed complete remission of proteinuria in two cases in group II (duration of remission was 4 and 8 months) and in one case in group III (duration of remission was 6 months) but in none in group I. Partial remission was observed in one case in group I, in three cases in group II and in one case in group III. During the observation period, improvement in kidney function was observed in two cases in group II but deterioration in kidney function was observed in one case in group I and in one other case in group III. We conclude that in patients with schistosomal nephropathy, none of the tried therapeutic regimens produce regression of the disease if given to patients with established disease.
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PMID:A prospective, randomized therapeutic trial for schistosomal specific nephropathy. 251 42

The complete DNA sequence of the Micrococcus luteus spectinomycin (spc) operon and its adjacent regions has been determined. The sequence has revealed the presence of genes that are homologous to those of the Escherichia coli ribosomal and related proteins, L14, L24, L5, S8, L6, L18, S5, L30, L15, and secretion protein Y (sec Y), and the gene for adenylate kinase (adk). The gene arrangement in the spc operon is essentially the same as that of E. coli except for the absence in the M. luteus spc operon of the genes for S14 and X protein that exist in the E. coli spc operon. SecY and adk seem to be composed of another operon (adk operon) with at least an open reading frame. The deduced amino acid sequences for these ribosomal proteins are well conserved among the two species (40-65% identity). Reflecting the high genomic guanine and cytosine (GC) content of M. luteus (74%), the codon usage of the genes is extremely biased toward use of G and C, about 94% of the codon third positions being G or C. Seven codons, AUA, AAA, AGA, UUA, GUA, CUA, and CAA, all of which have A at the codon third positions, are completely absent in the M. luteus genes examined. Out of 11 genes in the M. luteus spc and adk operons, 5 (10) use GUG (UGA) and 6 (1) use AUG (UAA) as an initiation (termination) codon.
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PMID:Spectinomycin operon of Micrococcus luteus: evolutionary implications of organization and novel codon usage. 253 72

Activated N-ras gene was isolated from human hepatoma tissue by DNA transfection assay coupled with the neomycin selection method and molecular cloning and a point mutation in the codon 61 (CAA----AAA) was noted. However, examination of the proportion of the mutated N-ras gene in the tumor part by molecular cloning and by hybridization using synthetic oligonucleotide probes indicated that the mutated gene occurred with very low frequency. The activated N-ras gene appears located only in a small fraction of the tumor cells. The experimental data indicate activation of this gene as possibly not the major cause of carcinoma, but rather a manifestation of tumor heterogeneity.
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PMID:Activated N-ras gene was found in human hepatoma tissue but only in a small fraction of the tumor cells. 253 92


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