Systematic Analysis of Tissue-Restricted miRISCs Reveals a Broad Role for microRNAs in Suppressing Basal Activation of the C. elegans Pathogen Response
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ABSTRACT:
ORGANISM(S): Caenorhabditis elegans
PROVIDER: GSE36419 | GEO | 2012/03/23
SECONDARY ACCESSION(S): PRJNA153221
REPOSITORIES: GEO
Similar Datasets
Project description:Gene regulation by microRNAs (miRNAs) under specific physiological conditions often involves complex interactions between multiple miRNAs and a large number of their targets, as well as coordination with other regulatory mechanisms, limiting the effectiveness of classical genetic methods to identify miRNA functions. We took a systematic approach to analyze the miRNA-induced silencing complex (miRISC) in individual tissues of C. elegans and found that mRNAs encoded by pathogen-responsive genes were dramatically over-represented in the intestinal miRISC, and that multiple miRNAs accumulated in the intestinal miRISCs upon infection. Inactivation of the miRISC or ablation of miRNAs from different families, resulted in over-expression of several pathogen-responsive genes under basal conditions and, surprisingly, enhanced worm survival on pathogenic Pseudomonas aeruginosa. These results indicate that much of the miRNA activity in the gut is dedicated to attenuating the activity of the pathogen response system, uncovering a novel and complex physiological function of the miRNA network. Each array was used for one biological replicate of a given experiment. One channel was used to probe Total RNA, the other was for IP RNA. Channels were swapped between biological replicates. 4 biological replicates for each asynchronous intestine IPs, 4 biological replicates for asynchronous muscle IP, 5 biolgoical replicates for L4 intestine IP, and two new biological replicates for the GFP control IP (previous biological replicates can be found in GSE9073: GSM230865-GSM2308657 and GSM230873-GSM230875).
2012-03-23 | E-GEOD-36419 | biostudies-arrayexpress
Project description:Identifying the physiological functions of microRNAs (miRNAs) is often challenging because miRNAs commonly impact gene expression under specific physiological conditions through complex miRNA::mRNA interaction networks and in coordination with other means of gene regulation, such as transcriptional regulation and protein degradation. Such complexity creates difficulties in dissecting miRNA functions through traditional genetic methods using individual miRNA mutations. To investigate the physiological functions of miRNAs in neurons, we combined a genetic M-bM-^@M-^\enhancerM-bM-^@M-^] approach complemented by biochemical analysis of neuronal miRNA-induced silencing complexes (miRISCs) in C. elegans. Total miRNA function can be compromised by mutating one of the two GW182 proteins (AIN-1), an important component of miRISC. We found that combining an ain-1 mutation with a mutation in unc-3, a neuronal transcription factor, resulted in an inappropriate entrance into the stress-induced, alternative larval stage known as dauer, indicating a role of miRNAs in preventing aberrant dauer formation. Analysis of this genetic interaction suggests that neuronal miRNAs perform such a role partly by regulating endogenous cyclic guanosine monophosphate (cGMP) signaling, potentially influencing two other dauer-regulating pathways. Through tissue-specific immunoprecipitations of miRISC, we identified miRNAs and their likely target mRNAs within neuronal tissue. We verified the biological relevance of several of these miRNAs and found that many miRNAs likely regulate dauer formation through multiple dauer-related targets. Further analysis of target mRNAs suggests potential miRNA involvement in various neuronal processes, but the importance of these miRNA::mRNA interactions remains unclear. Finally, we found that neuronal genes may be more highly regulated by miRNAs than intestinal genes. Overall, our study identifies miRNAs and their targets, and a physiological function of these miRNAs in neurons. It also suggests that compromising other aspects of gene expression, along with miRISC, can be an effective approach to reveal miRNA functions in specific tissues under specific physiological conditions. Each array was used for one biological replicate, where the red channel is used for IP RNA and the green channel is used for Total RNA. IP RNA indicates the transcripts associated with a neuronally expressed, GFP-tagged, miRISC. Five biological replicates were done on asynchronous worms. Please note the two different microarray platforms that were used.
2014-01-01 | E-GEOD-45871 | biostudies-arrayexpress
Project description:Identifying the physiological functions of microRNAs (miRNAs) is often challenging because miRNAs commonly impact gene expression under specific physiological conditions through complex miRNA::mRNA interaction networks and in coordination with other means of gene regulation, such as transcriptional regulation and protein degradation. Such complexity creates difficulties in dissecting miRNA functions through traditional genetic methods using individual miRNA mutations. To investigate the physiological functions of miRNAs in neurons, we combined a genetic “enhancer” approach complemented by biochemical analysis of neuronal miRNA-induced silencing complexes (miRISCs) in C. elegans. Total miRNA function can be compromised by mutating one of the two GW182 proteins (AIN-1), an important component of miRISC. We found that combining an ain-1 mutation with a mutation in unc-3, a neuronal transcription factor, resulted in an inappropriate entrance into the stress-induced, alternative larval stage known as dauer, indicating a role of miRNAs in preventing aberrant dauer formation. Analysis of this genetic interaction suggests that neuronal miRNAs perform such a role partly by regulating endogenous cyclic guanosine monophosphate (cGMP) signaling, potentially influencing two other dauer-regulating pathways. Through tissue-specific immunoprecipitations of miRISC, we identified miRNAs and their likely target mRNAs within neuronal tissue. We verified the biological relevance of several of these miRNAs and found that many miRNAs likely regulate dauer formation through multiple dauer-related targets. Further analysis of target mRNAs suggests potential miRNA involvement in various neuronal processes, but the importance of these miRNA::mRNA interactions remains unclear. Finally, we found that neuronal genes may be more highly regulated by miRNAs than intestinal genes. Overall, our study identifies miRNAs and their targets, and a physiological function of these miRNAs in neurons. It also suggests that compromising other aspects of gene expression, along with miRISC, can be an effective approach to reveal miRNA functions in specific tissues under specific physiological conditions.
2014-01-01 | GSE45871 | GEO
Project description:Background: Metazoan embryos undergo a maternal-to-zygotic transition (MZT) during which a subset of maternal gene products is eliminated and the zygotic genome becomes transcriptionally active. RNA-binding proteins (RBPs) and the microRNA-induced silencing complex (miRISC) â of which Argonaute 1 (AGO1) is a key component in Drosophila â target maternal mRNAs for degradation. The Drosophila Smaug, Brain tumor (BRAT) and Pumilio (PUM) RBPs direct the degradation of maternal mRNAs. Here we elucidate Smaugâs roles in regulation of miRNAs and miRISC during the MZT. Results: By global analysis of small RNAs at several stages during the MZT, we show that the vast majority of all miRNA species encoded by the Drosophila genome (85%) are expressed during the MZT. Whereas a subset of these miRNAs is loaded into oocytes by the mother and stays at constant levels during the MZT, dozens of miRNA species are either newly synthesized or re-expressed in the early embryo. Loss of Smaug has a profound effect on miRNAs but little effect on piRNAs or siRNAs. Smaug is required for production of new miRNAs during the MZT; Smaug-bound AGO1 reflects the constellation and abundance of the miRNAs present in early embryos; and Smaug is required for the increase in AGO1 protein levels that occurs during the MZT. As a consequence of low miRISC activity in smaug mutants, maternal mRNAs that are normally targeted for degradation by zygotic miRNAs fail to be cleared. BRAT and PUM share target mRNAs with miRISC during the MZT while the miR-309 miRNA family coregulates targets of BRAT but not PUM. Conclusions: Smaug controls the MZT through direct targeting of a subset of maternal mRNAs for degradation and, indirectly, through production and function of miRNAs and miRISC, which control clearance of a distinct subset of maternal mRNAs. BRAT and/or PUM function together with miRISC during the latter process. With respect to miRISC-dependent transcript degradation, Smaug is required (1) for the synthesis of miRNAs, (2) for synthesis and stabilization of AGO1, and (3) for action of AGO1 in association with its bound miRNAs. In smaug mutants a large number of maternal mRNAs persist and the MZT fails. Examination of miRNA expresssion at different time points in wild type and smuag mutant early embryos .
2016-09-06 | E-GEOD-82194 | biostudies-arrayexpress
Project description:The molecular mechanisms by which stem cell proliferation is precisely controlled during the course of regeneration are poorly understood. Namely, how a damaged tissue senses when to terminate the regeneration process, inactivates stem cell mitotic activity, and organizes ECM integrity remain fundamental unanswered questions. The Drosophila midgut intestinal stem cell (ISC) offers an excellent model system to study the molecular basis for stem cell inactivation. Here we show that a novel gene, CG6967 or dMOV10, is induced at the termination stage of midgut regeneration, and shows an inhibitory effect on ISC proliferation. dMOV10 encodes a putative component of the microRNA (miRNA) gene silencing complex (miRISC). Our data, along with previous studies on the mammalian MOV10, suggest that dMOV10 is not a core member of miRISC, but modulates miRISC activity as an additional component. Further analyses identified direct target mRNAs of dMOV10-containing miRISC, including Daughter against Dpp (Dad), a known inhibitor of BMP/TGF-β signaling. We show that RNAi knockdown of Dad significantly impaired ISC division during regeneration. We also identified miRNAs that are induced at the termination stage and their potential target transcripts. We propose that miRNA-mediated gene regulation contributes to the precise control of Drosophila midgut regeneration.
2020-07-14 | GSE154297 | GEO
Project description:The molecular mechanisms by which stem cell proliferation is precisely controlled during the course of regeneration are poorly understood. Namely, how a damaged tissue senses when to terminate the regeneration process, inactivates stem cell mitotic activity, and organizes ECM integrity remain fundamental unanswered questions. The Drosophila midgut intestinal stem cell (ISC) offers an excellent model system to study the molecular basis for stem cell inactivation. Here we show that a novel gene, CG6967 or dMOV10, is induced at the termination stage of midgut regeneration, and shows an inhibitory effect on ISC proliferation. dMOV10 encodes a putative component of the microRNA (miRNA) gene silencing complex (miRISC). Our data, along with previous studies on the mammalian MOV10, suggest that dMOV10 is not a core member of miRISC, but modulates miRISC activity as an additional component. Further analyses identified direct target mRNAs of dMOV10-containing miRISC, including Daughter against Dpp (Dad), a known inhibitor of BMP/TGF-β signaling. We show that RNAi knockdown of Dad significantly impaired ISC division during regeneration. We also identified miRNAs that are induced at the termination stage and their potential target transcripts. We propose that miRNA-mediated gene regulation contributes to the precise control of Drosophila midgut regeneration.
2020-07-14 | GSE154296 | GEO
Project description:The molecular mechanisms by which stem cell proliferation is precisely controlled during the course of regeneration are poorly understood. Namely, how a damaged tissue senses when to terminate the regeneration process, inactivates stem cell mitotic activity, and organizes ECM integrity remain fundamental unanswered questions. The Drosophila midgut intestinal stem cell (ISC) offers an excellent model system to study the molecular basis for stem cell inactivation. Here we show that a novel gene, CG6967 or dMOV10, is induced at the termination stage of midgut regeneration, and shows an inhibitory effect on ISC proliferation. dMOV10 encodes a putative component of the microRNA (miRNA) gene silencing complex (miRISC). Our data, along with previous studies on the mammalian MOV10, suggest that dMOV10 is not a core member of miRISC, but modulates miRISC activity as an additional component. Further analyses identified direct target mRNAs of dMOV10-containing miRISC, including Daughter against Dpp (Dad), a known inhibitor of BMP/TGF-β signaling. We show that RNAi knockdown of Dad significantly impaired ISC division during regeneration. We also identified miRNAs that are induced at the termination stage and their potential target transcripts. We propose that miRNA-mediated gene regulation contributes to the precise control of Drosophila midgut regeneration.
2020-07-14 | GSE154298 | GEO
Project description:MicroRNAs (miRNAs) associate with Argonaute (AGO) proteins to form a complex that directs mRNA repression. One way that miRNAs are regulated is at the level of their stability. Some animal miRNAs are destabilized through a pathway in which pairing to specialized RNA transcripts recruits the ZSWIM8 E3 ubiquitin ligase, which polyubiquitinates AGO, leading to its degradation and exposure of the miRNA to cellular nucleases. We found that 22 miRNAs in C. elegans are sensitive to loss of EBAX-1, the ZSWIM8 ortholog in nematodes, implying that these 22 miRNAs might be subject to this pathway of target-directed miRNA degradation (TDMD). These miRNAs included the embryonic miR-35–42 family, as well as other miRNAs among the least stable in the worm, suggesting that TDMD is a major pathway of miRNA destabilization in the worm. The excess miR-35–42 molecules that accumulated in ebax-1 mutants caused increased repression of their predicted target mRNAs and underwent 3′ trimming over time. In general, however, miRNAs sensitive to loss of EBAX-1 did not have a consistent pattern of either trimming or tailing. A previous study reports that in contrast to TDMD substrates in mammals and flies, the 3′ region of miR-35 is not required for its destabilization, raising the question of whether the 3′ regions of other miRNAs are dispensable for EBAX-1 sensitivity in nematodes. To address this question, we replaced the 3′ region of another EBAX-sensitive miRNA, miR-43, and found that this replacement greatly reduced EBAX-sensitivity in the worm. Together, these findings broaden the implied biological scope of TDMD-like regulation of miRNA stability in animals, and indicate that the requirement for miRNA 3′ sequences in this process is variable in the worm.
2024-11-04 | GSE267368 | GEO
Project description:MicroRNAs (miRNAs) associate with Argonaute (AGO) proteins to form a complex that directs mRNA repression. One way that miRNAs are regulated is at the level of their stability. Some animal miRNAs are destabilized through a pathway in which pairing to specialized RNA transcripts recruits the ZSWIM8 E3 ubiquitin ligase, which polyubiquitinates AGO, leading to its degradation and exposure of the miRNA to cellular nucleases. We found that 22 miRNAs in C. elegans are sensitive to loss of EBAX-1, the ZSWIM8 ortholog in nematodes, implying that these 22 miRNAs might be subject to this pathway of target-directed miRNA degradation (TDMD). These miRNAs included the embryonic miR-35–42 family, as well as other miRNAs among the least stable in the worm, suggesting that TDMD is a major pathway of miRNA destabilization in the worm. The excess miR-35–42 molecules that accumulated in ebax-1 mutants caused increased repression of their predicted target mRNAs and underwent 3′ trimming over time. In general, however, miRNAs sensitive to loss of EBAX-1 did not have a consistent pattern of either trimming or tailing. A previous study reports that in contrast to TDMD substrates in mammals and flies, the 3′ region of miR-35 is not required for its destabilization, raising the question of whether the 3′ regions of other miRNAs are dispensable for EBAX-1 sensitivity in nematodes. To address this question, we replaced the 3′ region of another EBAX-sensitive miRNA, miR-43, and found that this replacement greatly reduced EBAX-sensitivity in the worm. Together, these findings broaden the implied biological scope of TDMD-like regulation of miRNA stability in animals, and indicate that the requirement for miRNA 3′ sequences in this process is variable in the worm.
2024-11-04 | GSE267367 | GEO
Project description:Background: Metazoan embryos undergo a maternal-to-zygotic transition (MZT) during which a subset of maternal gene products is eliminated and the zygotic genome becomes transcriptionally active. RNA-binding proteins (RBPs) and the microRNA-induced silencing complex (miRISC) – of which Argonaute 1 (AGO1) is a key component in Drosophila – target maternal mRNAs for degradation. The Drosophila Smaug, Brain tumor (BRAT) and Pumilio (PUM) RBPs direct the degradation of maternal mRNAs. Here we elucidate Smaug’s roles in regulation of miRNAs and miRISC during the MZT. Results: By global analysis of small RNAs at several stages during the MZT, we show that the vast majority of all miRNA species encoded by the Drosophila genome (85%) are expressed during the MZT. Whereas a subset of these miRNAs is loaded into oocytes by the mother and stays at constant levels during the MZT, dozens of miRNA species are either newly synthesized or re-expressed in the early embryo. Loss of Smaug has a profound effect on miRNAs but little effect on piRNAs or siRNAs. Smaug is required for production of new miRNAs during the MZT; Smaug-bound AGO1 reflects the constellation and abundance of the miRNAs present in early embryos; and Smaug is required for the increase in AGO1 protein levels that occurs during the MZT. As a consequence of low miRISC activity in smaug mutants, maternal mRNAs that are normally targeted for degradation by zygotic miRNAs fail to be cleared. BRAT and PUM share target mRNAs with miRISC during the MZT while the miR-309 miRNA family coregulates targets of BRAT but not PUM. Conclusions: Smaug controls the MZT through direct targeting of a subset of maternal mRNAs for degradation and, indirectly, through production and function of miRNAs and miRISC, which control clearance of a distinct subset of maternal mRNAs. BRAT and/or PUM function together with miRISC during the latter process. With respect to miRISC-dependent transcript degradation, Smaug is required (1) for the synthesis of miRNAs, (2) for synthesis and stabilization of AGO1, and (3) for action of AGO1 in association with its bound miRNAs. In smaug mutants a large number of maternal mRNAs persist and the MZT fails.
2016-09-06 | GSE82194 | GEO