Appendix E: Function Sequence

2015 ◽  
pp. 241-246
Keyword(s):  
Function Sequence

scholarly journals Knock-Down of a Novel snoRNA in Tetrahymena Reveals a Dual Role in 5.8S rRNA Processing and Generation of a 26S rRNA Fragment

Biomolecules ◽  
2018 ◽  
Vol 8 (4) ◽  
pp. 128
Author(s):  
Kasper Andersen ◽  
Henrik Nielsen
Keyword(s):  
Small Nucleolar Rnas ◽  
Rrna Processing ◽  
Specific Chemical ◽  
Knock Down ◽  
5.8S Rrna ◽  
Rrna Species ◽  
26S Rrna ◽  
Precursor Molecules ◽  
Nucleolar Rnas ◽  
Function Sequence

In eukaryotes, 18S, 5.8S, and 28S rRNAs are transcribed as precursor molecules that undergo extensive modification and nucleolytic processing to form the mature rRNA species. Central in the process are the small nucleolar RNAs (snoRNAs). The majority of snoRNAs guide site specific chemical modifications but a few are involved in defining pre-rRNA cleavages. Here, we describe an unusual snoRNA (TtnuCD32) belonging to the box C/D subgroup from the ciliate Tetrahymena thermophila. We show that TtnuCD32 is unlikely to function as a modification guide snoRNA and that it is critical for cell viability. Cell lines with genetic knock-down of TtnuCD32 were impaired in growth and displayed two novel and apparently unrelated phenotypes. The most prominent phenotype is the accumulation of processing intermediates of 5.8S rRNA. The second phenotype is the decrease in abundance of a ~100 nt 26S rRNA fragment of unknown function. Sequence analysis demonstrated that TtnuCD32 share features with the essential snoRNA U14 but an alternative candidate (TtnuCD25) was more closely related to other U14 sequences. This, together with the fact that the observed rRNA processing phenotypes were not similar to what has been observed in U14 depleted cells, suggests that TtnuCD32 is a U14 homolog that has gained novel functions.

scholarly journals Differential Expression ESTs Associated with Fluorosis in Rats Liver

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Y. Q. He ◽  
Y. Pan ◽  
L. J. Ying ◽  
R. Zhao
Keyword(s):  
Differential Expression ◽  
Structural Damage ◽  
Molecular Mechanisms ◽  
Fluoride Toxicity ◽  
Glutathione S Transferase ◽  
Selenoprotein S ◽  
Damage Process ◽  
Chronic Fluorosis ◽  
Function Sequence ◽  
Microsomal Glutathione

The fluoride has volcanic activity and abundantly exists in environment combining with other elements as fluoride compounds. Recent researches indicated that the molecular mechanisms of intracellular fluoride toxicity were very complex. However, the molecular mechanisms underlying the effects on gene expression of chronic fluoride-induced damage is unknown, especially the detailed regulatory process of mitochondria. In the present study, we screened the differential expression ESTs associated with fluorosis by DDRT-PCR in rat liver. We gained 8 genes, 3 new ESTs, and 1 unknown function sequence and firstly demonstrated that microsomal glutathione S-transferase 1 (MGST1), ATP synthase H+transporting mitochondrial F0complex subunit C1, selenoprotein S, mitochondrial IF1 protein, and mitochondrial succinyl-CoA synthetase alpha subunit were participated in mitochondria metabolism, functional and structural damage process caused by chronic fluorosis. This information will be very helpful for understanding the molecular mechanisms of fluorosis.

scholarly journals Sequence Tolerance of the Phage λ PRM Promoter: Implications for Evolution of Gene Regulatory Circuitry

2004 ◽  
Vol 186 (23) ◽  
pp. 7988-7999 ◽  
Author(s):  
Christine B. Michalowski ◽  
Megan D. Short ◽  
John W. Little
Keyword(s):  
Binding Sites ◽  
Present Form ◽  
Wild Type ◽  
Prophage Induction ◽  
Wide Range ◽  
Sequences Analysis ◽  
Gene Regulatory ◽  
Exact Sequences ◽  
Function Sequence ◽  
Regulatory Sites

ABSTRACT Much of the gene regulatory circuitry of phage λ centers on a complex region called the O R region. This ∼100-bp region is densely packed with regulatory sites, including two promoters and three repressor-binding sites. The dense packing of this region is likely to impose severe constraints on its ability to change during evolution, raising the question of how the specific arrangement of sites and their exact sequences could evolve to their present form. Here we ask whether the sequence of a cis-acting site can be widely varied while retaining its function; if it can, evolution could proceed by a larger number of paths. To help address this question, we developed aλ cloning vector that allowed us to clone fragments spanning the O R region. By using this vector, we carried out intensive mutagenesis of the P RM promoter, which drives expression of CI repressor and is activated by CI itself. We made a pool of fragments in which 8 of the 12 positions in the− 35 and −10 regions were randomized and cloned this pool into the vector, making a pool of P RM variant phage. About 10% of the P RM variants were able to lysogenize, suggesting that the λ regulatory circuitry is compatible with a wide range of P RM sequences. Analysis of several of these phages indicated a range of behaviors in prophage induction. Several isolates had induction properties similar to those of the wild type, and their promoters resembled the wild type in their responses to CI. We term this property of different sequences allowing roughly equivalent function “sequence tolerance ” and discuss its role in the evolution of gene regulatory circuitry.

Sign in / Sign up

Export Citation Format

Share Document