Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:4.1.2.13 (aldolase)
 3,461 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A model for random cross-linking of identical monomers diffusing in a membrane was formulated to test whether rhodopsin's cross-linking behavior was quantitatively consistent with a monomeric structure. Cross-linking was performed on rhodopsin both in intact retinas and in isolated rod outer segment (ROS) membranes using the reagent glutaraldehyde. The distribution of covalent oligomers formed was analyzed by SDS-polyacrylamide gel electrophoresis and compared to predictions for the random model. A similar analysis was made for ROS membranes cross-linked by diisocyanatohexane and retinas cross-linked by cupric ion complexed with o-phenanthroline. Patterns of cross-linking produced by these three reagents are reasonably consistent with the monomer model. Glutaraldehyde was also used to cross-link the tetrameric protein aldolase in order to verify that cross-linking of a stable oligomer, under conditions comparable to those used for ROS, yielded the pattern predicted for a tetrameric protein having D2 symmetry. This pattern is markedly different from the one for a random-collision model. Moreover, a comparison of rates showed that aldolase cross-linking with glutaraldehyde is significantly faster than cross-linking of membrane-bound rhodopsin. It is concluded that rhodopsin is monomeric in dark-adapted photoreceptor membranes and that the observed cross-linking results from collisions between diffusing rhodopsin molecules.
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PMID:Cross-linking of dark-adapted frog photoreceptor disk membranes. Evidence for monomeric rhodopsin. 391 79

ESTs constitute rapid and informative tools with which to study gene-expression profiles of the diverse stages of the schistosome life cycle. Following a comprehensive EST study of adult worms, analysis has now targeted the cercaria, the parasite larval form responsible for infection of the vertebrate host. Two Schistosoma mansoni cercarial cDNA libraries were examined and partial sequence obtained from 957 randomly selected clones. On the basis of database searches, 551 (57.6%) ESTs generated had no homologs in the public databases whilst 308 (32.2%) were putatively identified, totaling 859 informative ESTs. The remaining 98 (10.2%) were uninformative ESTs (ribosomal RNA and non-coding mitochondrial sequences). By clustering analysis we have identified 453 different genes. The most common sequences in both libraries represented Sm8 calcium binding protein (8% of ESTs), fructose-1,6-bisphosphate aldolase, glyceraldehyde-3-phosphate dehydrogenase, cytochrome oxidase subunit 1, ATP guanidine kinase and triose phosphate isomerase. One hundred and nineteen identified genes were sorted into 11 functional categories, with genes associated with energy metabolism being the most abundant (13%) and diverse. The diversity and abundance of genes associated with the transcription/translation machinery and with regulatory/signaling functions were also marked. A paramyosin transcript was identified, indicating that this gene is not exclusively expressed in adult worms and sporocysts (as had been suggested previously). The possible physiological relevance to cercariae of the presence of transcripts with homology to calcium binding proteins of the EF-hand superfamily, Gq-coupled rhodopsin photoreceptor, rod phosphodiesterase 8 subunit and peripheral-type benzodiazepine receptor is discussed.
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PMID:Analysis of the gene expression profile of Schistosoma mansoni cercariae using the expressed sequence tag approach. 1051 83

Paralogy is a pervasive problem in trying to use nuclear gene sequences to infer species phylogenies. One strategy for dealing with this problem is to infer species phylogenies from gene trees using reconciled trees, rather than directly from the sequences themselves. In this approach, the optimal species tree is the tree that requires the fewest gene duplications to be invoked. Because reconciled trees can identify orthologous from paralogous sequences, there is no need to do this prior to the analysis. Multiple gene trees can be analyzed simultaneously; however, the problem of nonuniform gene sampling raises practical problems which are discussed. In this paper the technique is applied to phylogenies for nine vertebrate genes (aldolase, alpha-fetoprotein, lactate dehydrogenase, prolactin, rhodopsin, trypsinogen, tyrosinase, vassopressin, and Wnt-7). The resulting species tree shows much similarity with currently accepted vertebrate relationships.
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PMID:Extracting species trees from complex gene trees: reconciled trees and vertebrate phylogeny. 1063 Oct 44