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Full-Text Articles in Life Sciences
Drosophila Rnase Z Processes Mitochondrial And Nuclear Pre-Trna 3′ Ends In Vivo, Edward B. Dubrovsky, Veronica A. Dubrovskaya, Louis Levinger, Steffen Schiffer, Anita Marchfelder
Drosophila Rnase Z Processes Mitochondrial And Nuclear Pre-Trna 3′ Ends In Vivo, Edward B. Dubrovsky, Veronica A. Dubrovskaya, Louis Levinger, Steffen Schiffer, Anita Marchfelder
Dartmouth Scholarship
Although correct tRNA 3′ ends are crucial for protein biosynthesis, generation of mature tRNA 3′ ends in eukaryotes is poorly understood and has so far only been investigated in vitro. We report here for the first time that eukaryotic tRNA 3′ end maturation is catalysed by the endonuclease RNase Z in vivo. Silencing of the JhI‐1 gene (RNase Z homolog) in vivo with RNAi in Drosophila S2 cultured cells causes accumulation of nuclear and mitochondrial pre‐tRNAs, suggesting that JhI‐1 encodes both forms of the tRNA 3′ endonuclease RNase Z, and establishing its biological role in endonucleolytic tRNA 3′ …
Phylogenetic Analysis Of The Formin Homology 2 Domain, Henry N. Higgs, Kevin J. Peterson
Phylogenetic Analysis Of The Formin Homology 2 Domain, Henry N. Higgs, Kevin J. Peterson
Dartmouth Scholarship
Formin proteins are key regulators of eukaryotic actin filament assembly and elongation, and many species possess multiple formin isoforms. A nomenclature system based on fundamental features would be desirable, to aid the rapid identification and characterization of novel formins. In this article, we attempt to systematize the formin family by performing phylogenetic analyses of the formin homology 2 (FH2) domain, an independently folding region common to all formins, which alone can influence actin dynamics. Through database searches, we identify 101 FH2 domains from 26 eukaryotic species, including 15 in mice. Sequence alignments reveal a highly conserved yeast-specific insert in the …
Pf15p Is The Chlamydomonas Homologue Of The Katanin P80 Subunit And Is Required For Assembly Of Flagellar Central Microtubules, Erin E. Dymek, Paul A. Lefebvre, Elizabeth F. Smith
Pf15p Is The Chlamydomonas Homologue Of The Katanin P80 Subunit And Is Required For Assembly Of Flagellar Central Microtubules, Erin E. Dymek, Paul A. Lefebvre, Elizabeth F. Smith
Dartmouth Scholarship
Numerous studies have indicated that the central apparatus plays a significant role in regulating flagellar motility, yet little is known about how the central pair of microtubules or their associated projections assemble. Several Chlamydomonas mutants are defective in central apparatus assembly. For example, mutant pf15 cells have paralyzed flagella that completely lack the central pair of microtubules. We have cloned the wild-type PF15 gene and confirmed its identity by rescuing the motility and ultrastructural defects in two pf15 alleles, the original pf15a mutant and a mutant generated by insertional mutagenesis. Database searches using the 798-amino-acid polypeptide predicted from the complete …
The C. Elegans Heterochronic Gene Lin-46 Affects Developmental Timing At Two Larval Stages And Encodes A Relative Of The Scaffolding Protein Gephyrin, A. S.-R. Pepper, Jill E. Mccane, Kevin Kemper, Dennis Au Yeung, Rosalind C. Lee, Victor Ambros, Eric G. Moss
The C. Elegans Heterochronic Gene Lin-46 Affects Developmental Timing At Two Larval Stages And Encodes A Relative Of The Scaffolding Protein Gephyrin, A. S.-R. Pepper, Jill E. Mccane, Kevin Kemper, Dennis Au Yeung, Rosalind C. Lee, Victor Ambros, Eric G. Moss
Dartmouth Scholarship
The succession of developmental events in the C. elegans larva is governed by the heterochronic genes. When mutated, these genes cause either precocious or retarded developmental phenotypes, in which stage-specific patterns of cell division and differentiation are either skipped or reiterated, respectively. We identified a new heterochronic gene, lin-46, from mutations that suppress the precocious phenotypes caused by mutations in the heterochronic genes lin-14 and lin-28. lin-46 mutants on their own display retarded phenotypes in which cell division patterns are reiterated and differentiation is prevented in certain cell lineages. Our analysis indicates that lin-46 acts at a step immediately downstream …
A Dominant-Negative Fur Mutation In Bradyrhizobium Japonicum, Heather P. Benson, Kristin Levier, Mary Lou Guerinot
A Dominant-Negative Fur Mutation In Bradyrhizobium Japonicum, Heather P. Benson, Kristin Levier, Mary Lou Guerinot
Dartmouth Scholarship
In many bacteria, the ferric uptake regulator (Fur) protein plays a central role in the regulation of iron uptake genes. Because iron figures prominently in the agriculturally important symbiosis between soybean and its nitrogen-fixing endosymbiont Bradyrhizobium japonicum, we wanted to assess the role of Fur in the interaction. We identified a fur mutant by selecting for manganese resistance. Manganese interacts with the Fur protein and represses iron uptake genes. In the presence of high levels of manganese, bacteria with a wild-type copy of the furgene repress iron uptake systems and starve for iron, whereas fur mutants fail to …