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)

The glycogen phosphorylase-2 (GP2) activity that appears during the cell differentiation of Dictyostelium was purified to homogeneity. The molecular weight of the nondenatured enzyme was 200,000 as determined by Sephacryl S-300 gel filtration and was 107,000 on sodium dodecyl sulfate-polyacrylamide gel electrophoresis, suggesting that the native enzyme consists of two similar subunits. The intact protein was digested with trypsin and protease V8, and the resulting peptides were purified by microbore high pressure liquid chromatography. The peptides were sequenced, and oligonucleotides were constructed for polymerase chain reaction amplification of the GP2 gene from Dictyostelium genomic DNA template. The resulting polymerase chain reaction products were sequenced directly and were confirmed to encode portions of the GP2 gene. These fragments were used to probe a partial EcoRI genomic library for the remainder of the GP2 gene. The nucleotide sequence of the GP2-selected clones revealed an open reading frame of 2975 base pairs that was interrupted by two introns of 109 and 105 base pairs, respectively. The open reading frame encoded a protein of 992 amino acids with a calculated molecular mass of 112,500 Da and an isoelectric point of 6.4. An unusual sequence within the second exon of GP2, in which the triplet CAA was repeated 11 times, resulted in 11 in-frame glutamine residues of a possible 15 amino acids coded for by this region. The CAA repeat was transcribed, as shown by the sequence of cDNA. Comparison of the amino acid sequence of Dictyostelium GP2 to the phosphorylases from other organisms revealed that the Dictyostelium protein was 50 and 44% identical to yeast and rabbit muscle phosphorylases, respectively. Northern blot analysis showed that GP2 mRNA was absent in amebas and the early stages of development, reached a maximum level of expression at the slug stage, and then decreased in the terminal stages of development. Comparison of the mRNA expression with the appearance of GP2 enzyme protein and enzyme activity revealed that gp2 mRNA and a 113-kDa GP2 enzyme peptide were expressed concurrently at 10 h of development. However, enzyme activity did not appear until 18 h, coincident with a decrease in the level of the 113-kDa peptide and a corresponding increase in the amount of a 106-kDa GP2 peptide. Addition of cAMP to aggregation-competent cells in liquid culture resulted in the induction of GP2 mRNA, GP2 protein, and GP2 enzyme activity.
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PMID:Cloning, structural analysis, and expression of the glycogen phosphorylase-2 gene in Dictyostelium. 131 Mar 12

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

The Dictyostelium discoideum genome has been sequenced, assembled and annotated to a high degree of reliability. The parts-list of proteins and RNA encoded by the six chromosomes can now be accessed and analyzed. One of the initial surprises was the remarkably large number of genes that are shared with plants, animals, and fungi that must have been present in their common progenitor over a billion years ago. The genome encodes a total of about 10,300 proteins including protein families involved in cytoskeletal control, posttranslational protein modification, detoxification, secondary metabolism, cell adhesion, and signal transduction. The genome has a higher proportion of homopolymeric tracts and simple sequence repeats, such as [CAA]n, than most other genomes. Triplet repeats in translated regions produce the highest known proportion of polyglutamine tracts in any known proteome. Phylogenetic analyses based on complete proteomes confirm that the amoebozoa are a sister group to the animals and fungi, distinct from plants and early diverging species such as Leishmania, Plasmodium, or Giardia. The completed Dictyostelium sequence opens the door to large-scale functional exploration of its genome.
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PMID:The Genome of Dictyostelium discoideum. 1695 82