Translation Dependence of siRNA precursors in T. thermophila
Research Mentor(s)
Lee, Suzanne
Description
Many organisms possess “junk” DNA that, in some cases, may be harmful if expressed, requiring cellular pathways to prevent such expression. Tetrahymena thermophila is one such organism and it appears to employ an RNA interference (RNAi) pathway to limit the expression of repetitive or unusually structured non-protein coding regions of the genome through small interfering RNA (siRNA) production. However, whether siRNA precursors generated from these DNA regions are also degraded by translation-dependent RNA quality control pathways has been unclear. We have found that treatment of Tetrahymena thermophila with the translational inhibitor cycloheximide (CHX) causes an accumulation of a subset of siRNA producing transcripts while also reducing or leaving unchanged the levels of others. This suggests that at least some of the siRNA precursors may be subject to translation-dependent degradation (TDD), though other possible explanations remain to be ruled out. Our current efforts are focused on investigating possible mechanisms behind the response of siRNA precursors to CHX. We are examining two hypotheses: for one, translation dependent decay (TDD) may be acting on siRNA precursors in parallel with or in competition with RNAi. Alternatively, CHX may interact with a transcriptional inhibitor. In this model, the action of CHX blocks the inhibitor, upregulating transcription. We also plan on examining the effects of CHX on other siRNA precursors.
Document Type
Event
Start Date
17-5-2018 9:00 AM
End Date
17-5-2018 12:00 PM
Department
Biology
Genre/Form
student projects, posters
Subjects – Topical (LCSH)
Molecular biology; Biochemistry; RNA--Metabolism
Type
Image
Rights
Copying of this document in whole or in part is allowable only for scholarly purposes. It is understood, however, that any copying or publication of this documentation for commercial purposes, or for financial gain, shall not be allowed without the author's written permission.
Language
English
Format
application/pdf
Translation Dependence of siRNA precursors in T. thermophila
Many organisms possess “junk” DNA that, in some cases, may be harmful if expressed, requiring cellular pathways to prevent such expression. Tetrahymena thermophila is one such organism and it appears to employ an RNA interference (RNAi) pathway to limit the expression of repetitive or unusually structured non-protein coding regions of the genome through small interfering RNA (siRNA) production. However, whether siRNA precursors generated from these DNA regions are also degraded by translation-dependent RNA quality control pathways has been unclear. We have found that treatment of Tetrahymena thermophila with the translational inhibitor cycloheximide (CHX) causes an accumulation of a subset of siRNA producing transcripts while also reducing or leaving unchanged the levels of others. This suggests that at least some of the siRNA precursors may be subject to translation-dependent degradation (TDD), though other possible explanations remain to be ruled out. Our current efforts are focused on investigating possible mechanisms behind the response of siRNA precursors to CHX. We are examining two hypotheses: for one, translation dependent decay (TDD) may be acting on siRNA precursors in parallel with or in competition with RNAi. Alternatively, CHX may interact with a transcriptional inhibitor. In this model, the action of CHX blocks the inhibitor, upregulating transcription. We also plan on examining the effects of CHX on other siRNA precursors.
Comments
Outstanding Poster Award Recipient