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Tao J, Cui J, Xu Y, Fan Y, Hong G, Zhou Q, Wang G, Li L, Han Y, Xu C, Wang W, Cai S, Zhang X. MAEL in human cancers and implications in prognostication and predicting benefit from immunotherapy over VEGFR/mTOR inhibitors in clear cell renal cell carcinoma: a bioinformatic analysis. Aging (Albany NY) 2024; 16:2090-2122. [PMID: 38301040 PMCID: PMC10911358 DOI: 10.18632/aging.205470] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2023] [Accepted: 12/13/2023] [Indexed: 02/03/2024]
Abstract
Maelstrom (MAEL), a novel cancer/testis-associated gene, may facilitate the initiation and progression of human malignancies, warranting comprehensive investigations. Single-cell and tissue-bulk transcriptomic data demonstrated higher MAEL expression in testis (spermatogonia/spermatocyte), kidney (proximal tubular cell), and brain (neuron/astrocyte), and corresponding cancers, including testicular germ cell tumor, glioma, papillary renal cell carcinoma, and clear cell renal cell carcinoma (ccRCC). Of these cancers, only in ccRCC did MAEL expression exhibit associations with both recurrence-free survival and overall survival. High MAEL expression was associated with an anti-inflammatory tumor immune microenvironment and VEGFR/mTOR activation in ccRCC tissues and high sensitivities to VEGFR/PI3K-AKT-mTOR inhibitors in ccRCC cell lines. Consistent with these, low rather than high MAEL expression indicated remarkable progression-free survival benefits from immune checkpoint inhibitor (ICI)-based immunotherapies over VEGFR/mTOR inhibitors in two large phase III trials (JAVELIN Renal 101 and CheckMate-025). MAEL is a biologically and clinically significant determinant with potential for prognostication after nephrectomy and patient selection for VEGFR/mTOR inhibitors and immunotherapy-based treatments.
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Affiliation(s)
- Jin Tao
- Department of Urology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China
| | - Jinshan Cui
- Department of Urology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China
| | - Yu Xu
- Burning Rock Biotech, Guangzhou, Guangdong, China
| | - Yafeng Fan
- Department of Urology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China
| | - Guodong Hong
- Department of Urology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China
| | - Qiaoxia Zhou
- Burning Rock Biotech, Guangzhou, Guangdong, China
| | | | - Leo Li
- Burning Rock Biotech, Guangzhou, Guangdong, China
| | - Yusheng Han
- Burning Rock Biotech, Guangzhou, Guangdong, China
| | - Chunwei Xu
- Institute of Basic Medicine and Cancer (IBMC), Chinese Academy of Sciences, Hangzhou, Zhejiang, China
| | - Wenxian Wang
- Department of Clinical Trial, The Cancer Hospital of the University of Chinese Academy of Sciences (Zhejiang Cancer Hospital), Hangzhou, Zhejiang, China
| | - Shangli Cai
- Burning Rock Biotech, Guangzhou, Guangdong, China
| | - Xuepei Zhang
- Department of Urology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China
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2
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Zhou L, Ou S, Liang T, Li M, Xiao P, Cheng J, Zhou J, Yuan L. MAEL facilitates metabolic reprogramming and breast cancer progression by promoting the degradation of citrate synthase and fumarate hydratase via chaperone-mediated autophagy. FEBS J 2023. [PMID: 36866961 DOI: 10.1111/febs.16768] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Revised: 01/15/2023] [Accepted: 01/30/2023] [Indexed: 03/04/2023]
Abstract
Metabolic reprogramming is a hallmark of cancer. Several studies have shown that inactivation of Krebs cycle enzymes, such as citrate synthase (CS) and fumarate hydratase (FH), facilitates aerobic glycolysis and cancer progression. MAEL has been shown to play an oncogenic role in bladder, liver, colon, and gastric cancers, but its role in breast cancer and metabolism is still unknown. Here, we demonstrated that MAEL promoted malignant behaviours and aerobic glycolysis in breast cancer cells. Mechanistically, MAEL interacted with CS/FH and HSAP8 via its MAEL domain and HMG domain, respectively, and then enhanced the binding affinity of CS/FH with HSPA8, facilitating the transport of CS/FH to the lysosome for degradation. MAEL-induced degradation of CS and FH could be suppressed by the lysosome inhibitors leupeptin and NH4 Cl, but not by the macroautophagy inhibitor 3-MA or the proteasome inhibitor MG132. These results suggested that MAEL promoted the degradation of CS and FH via chaperone-mediated autophagy (CMA). Further studies showed that the expression of MAEL was significantly and negatively correlated with CS and FH in breast cancer. Moreover, overexpression of CS or/and FH could reverse the oncogenic effects of MAEL. Taken together, MAEL promotes a metabolic shift from oxidative phosphorylation to glycolysis by inducing CMA-dependent degradation of CS and FH, thereby promoting breast cancer progression. These findings have elucidated a novel molecular mechanism of MAEL in cancer.
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Affiliation(s)
- Lin Zhou
- State Key Laboratory of Developmental Biology of Freshwater Fish & Key Laboratory of Protein Chemistry and Developmental Biology of the Ministry of Education, College of Life Science, Hunan Normal University, Changsha, China.,College of Clinical Laboratory, Changsha Medical University, China
| | - Shuobo Ou
- State Key Laboratory of Developmental Biology of Freshwater Fish & Key Laboratory of Protein Chemistry and Developmental Biology of the Ministry of Education, College of Life Science, Hunan Normal University, Changsha, China
| | - Ting Liang
- State Key Laboratory of Developmental Biology of Freshwater Fish & Key Laboratory of Protein Chemistry and Developmental Biology of the Ministry of Education, College of Life Science, Hunan Normal University, Changsha, China
| | - Meiling Li
- State Key Laboratory of Developmental Biology of Freshwater Fish & Key Laboratory of Protein Chemistry and Developmental Biology of the Ministry of Education, College of Life Science, Hunan Normal University, Changsha, China
| | - Pei Xiao
- State Key Laboratory of Developmental Biology of Freshwater Fish & Key Laboratory of Protein Chemistry and Developmental Biology of the Ministry of Education, College of Life Science, Hunan Normal University, Changsha, China
| | - Jiaxin Cheng
- State Key Laboratory of Developmental Biology of Freshwater Fish & Key Laboratory of Protein Chemistry and Developmental Biology of the Ministry of Education, College of Life Science, Hunan Normal University, Changsha, China
| | - Jianlin Zhou
- State Key Laboratory of Developmental Biology of Freshwater Fish & Key Laboratory of Protein Chemistry and Developmental Biology of the Ministry of Education, College of Life Science, Hunan Normal University, Changsha, China
| | - Liqin Yuan
- Department of General Surgery, The Second Xiangya Hospital, Central South University, Changsha, China
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3
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He WP, Yang GP, Yang ZX, Shen HW, You ZS, Yang GF. Maelstrom promotes tumor metastasis through regulation of FGFR4 and epithelial-mesenchymal transition in epithelial ovarian cancer. J Ovarian Res 2022; 15:55. [PMID: 35513870 PMCID: PMC9074322 DOI: 10.1186/s13048-022-00992-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2022] [Accepted: 04/27/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Increasing evidence has indicated that Maelstrom (MAEL) plays an oncogenic role in various human carcinomas. However, the exact function and mechanisms by which MAEL acts in epithelial ovarian cancer (EOC) remain unclear. RESULTS This study demonstrated that MAEL was frequently overexpressed in EOC tissues and cell lines. Overexpression of MAEL was positively correlated with the histological grade of tumors, FIGO stage, and pT/pN/pM status (p < 0.05), and it also acted as an independent predictor of poor patient survival (p < 0.001). Ectopic overexpression of MAEL substantially promoted invasiveness/metastasis and induced epithelial-mesenchymal transition (EMT), whereas silencing MAEL by short hairpin RNA effectively inhibited its oncogenic function and attenuated EMT. Further study demonstrated that fibroblast growth factor receptor 4 (FGFR4) was a critical downstream target of MAEL in EOC, and the expression levels of FGFR4 were significantly associated with MAEL. (P < 0.05). CONCLUSION Our findings suggest that overexpression of MAEL plays a crucial oncogenic role in the development and progression of EOC through the upregulation of FGFR4 and subsequent induction of EMT, and also provide new insights on its potential as a therapeutic target for EOC.
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Affiliation(s)
- Wei-Peng He
- Department of Gynecology, the First Affiliated Hospital, Sun Yat-Sen University, No. 58, Zhongshan Road II, Guangzhou, 510080, China
| | - Gui-Ping Yang
- Department of Gynecology, the First Affiliated Hospital, Sun Yat-Sen University, No. 58, Zhongshan Road II, Guangzhou, 510080, China
| | - Zun-Xian Yang
- Department of Gynecology, the First Affiliated Hospital, Sun Yat-Sen University, No. 58, Zhongshan Road II, Guangzhou, 510080, China
| | - Hong-Wei Shen
- Department of Gynecology, the First Affiliated Hospital, Sun Yat-Sen University, No. 58, Zhongshan Road II, Guangzhou, 510080, China
| | - Ze-Shan You
- Department of Gynecology, the First Affiliated Hospital, Sun Yat-Sen University, No. 58, Zhongshan Road II, Guangzhou, 510080, China
| | - Guo-Fen Yang
- Department of Gynecology, the First Affiliated Hospital, Sun Yat-Sen University, No. 58, Zhongshan Road II, Guangzhou, 510080, China.
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4
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Kenny A, Morgan MB, Mohr S, Macdonald PM. Knock down analysis reveals critical phases for specific oskar noncoding RNA functions during Drosophila oogenesis. G3-GENES GENOMES GENETICS 2021; 11:6377782. [PMID: 34586387 PMCID: PMC8849117 DOI: 10.1093/g3journal/jkab340] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Accepted: 09/17/2021] [Indexed: 12/02/2022]
Abstract
The oskar transcript, acting as a noncoding RNA, contributes to a diverse set of pathways in the Drosophila ovary, including karyosome formation, positioning of the microtubule organizing center (MTOC), integrity of certain ribonucleoprotein particles, control of nurse cell divisions, restriction of several proteins to the germline, and progression through oogenesis. How oskar mRNA acts to perform these functions remains unclear. Here, we use a knock down approach to identify the critical phases when oskar is required for three of these functions. The existing transgenic shRNA for removal of oskar mRNA in the germline targets a sequence overlapping a regulatory site bound by Bruno1 protein to confer translational repression, and was ineffective during oogenesis. Novel transgenic shRNAs targeting other sites were effective at strongly reducing oskar mRNA levels and reproducing phenotypes associated with the absence of the mRNA. Using GAL4 drivers active at different developmental stages of oogenesis, we found that early loss of oskar mRNA reproduced defects in karyosome formation and positioning of the MTOC, but not arrest of oogenesis. Loss of oskar mRNA at later stages was required to prevent progression through oogenesis. The noncoding function of oskar mRNA is thus required for more than a single event.
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Affiliation(s)
- Andrew Kenny
- Department of Molecular Biosciences The University of Texas at Austin Austin, TX 78712 United States of America
| | - Miles B Morgan
- Department of Molecular Biosciences The University of Texas at Austin Austin, TX 78712 United States of America
| | - Sabine Mohr
- Department of Molecular Biosciences The University of Texas at Austin Austin, TX 78712 United States of America
| | - Paul M Macdonald
- Department of Molecular Biosciences The University of Texas at Austin Austin, TX 78712 United States of America
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5
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Onishi R, Yamanaka S, Siomi MC. piRNA- and siRNA-mediated transcriptional repression in Drosophila, mice, and yeast: new insights and biodiversity. EMBO Rep 2021; 22:e53062. [PMID: 34347367 PMCID: PMC8490990 DOI: 10.15252/embr.202153062] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Revised: 06/10/2021] [Accepted: 07/19/2021] [Indexed: 12/26/2022] Open
Abstract
The PIWI‐interacting RNA (piRNA) pathway acts as a self‐defense mechanism against transposons to maintain germline genome integrity. Failures in the piRNA pathway cause DNA damage in the germline genome, disturbing inheritance of “correct” genetic information by the next generations and leading to infertility. piRNAs execute transposon repression in two ways: degrading their RNA transcripts and compacting the genomic loci via heterochromatinization. The former event is mechanistically similar to siRNA‐mediated RNA cleavage that occurs in the cytoplasm and has been investigated in many species including nematodes, fruit flies, and mammals. The latter event seems to be mechanistically parallel to siRNA‐centered kinetochore assembly and subsequent chromosome segregation, which has so far been studied particularly in fission yeast. Despite the interspecies conservations, the overall schemes of the nuclear events show clear biodiversity across species. In this review, we summarize the recent progress regarding piRNA‐mediated transcriptional silencing in Drosophila and discuss the biodiversity by comparing it with the equivalent piRNA‐mediated system in mice and the siRNA‐mediated system in fission yeast.
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Affiliation(s)
- Ryo Onishi
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
| | - Soichiro Yamanaka
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
| | - Mikiko C Siomi
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
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6
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Kenny A, Morgan MB, Macdonald PM. Different roles for the adjoining and structurally similar A-rich and poly(A) domains of oskar mRNA: Only the A-rich domain is required for oskar noncoding RNA function, which includes MTOC positioning. Dev Biol 2021; 476:117-127. [PMID: 33798537 DOI: 10.1016/j.ydbio.2021.03.021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2020] [Revised: 03/23/2021] [Accepted: 03/24/2021] [Indexed: 11/17/2022]
Abstract
Drosophila oskar (osk) mRNA has both coding and noncoding functions, with the latter required for progression through oogenesis. Noncoding activity is mediated by the osk 3' UTR. Three types of cis elements act most directly and are clustered within the final ~120 nucleotides of the 3' UTR: multiple binding sites for the Bru1 protein, a short highly conserved region, and A-rich sequences abutting the poly(A) tail. Here we extend the characterization of these elements and their functions, providing new insights into osk noncoding RNA function and the makeup of the cis elements. We show that all three elements are required for correct positioning of the microtubule organizing center (MTOC), a defect not previously reported for any osk mutant. Normally, the MTOC is located at the posterior of the oocyte during previtellogenic stages of oogenesis, and this distribution underlies the strong posterior enrichment of many mRNAs transported into the oocyte from the nurse cells. When osk noncoding function was disrupted the MTOC was dispersed in the oocyte and osk mRNA failed to be enriched at the posterior, although transport to the oocyte was not affected. A previous study did not detect loss of posterior enrichment for certain osk mutants lacking noncoding activity (Kanke et al., 2015). This discrepancy may be due to use of imaging aimed at monitoring transport to the oocyte rather than posterior enrichment. Involvement in MTOC positioning suggests that the osk noncoding function may act in conjunction with genes whose loss has similar effects, and that osk function may extend to other processes requiring those genes. Further characterization of the cis elements required for osk noncoding function included completion of saturation mutagenesis of the most highly conserved region, providing critical information for evaluating the possible contribution of candidate binding factors. The 3'-most cis element is a cluster of A-rich sequences, the ARS. The close juxtaposition and structural similarity of the ARS and poly(A) tail raised the possibility that they comprise an extended A-rich element required for osk noncoding function. We found that absence of the poly(A) tail did not mimic the effects of mutation of the ARS, causing neither arrest of oogenesis nor mispositioning of osk mRNA in previtellogenic stage oocytes. Thus, the ARS and the poly(A) tail are not interchangeable for osk noncoding RNA function, suggesting that the role of the ARS is not in recruitment of Poly(A) binding protein (PABP), the protein that binds the poly(A) tail. Furthermore, although PABP has been implicated in transport of osk mRNA from the nurse cells to the oocyte, mutation of the ARS in combination with loss of the poly(A) tail did not disrupt transport of osk mRNA into the oocyte. We conclude that PABP acts indirectly in osk mRNA transport, or is associated with osk mRNA independent of an A-rich binding site. Although the poly(A) tail was not required for osk mRNA transport into the oocyte, its absence was associated with a novel osk mRNA localization defect later in oogenesis, potentially revealing a previously unrecognized step in the localization process.
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Affiliation(s)
- Andrew Kenny
- Department of Molecular Biosciences, The University of Texas at Austin, United States
| | - Miles B Morgan
- Department of Molecular Biosciences, The University of Texas at Austin, United States
| | - Paul M Macdonald
- Department of Molecular Biosciences, The University of Texas at Austin, United States.
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7
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Chen K, Chen S, Xu J, Yu Y, Liu Z, Tan A, Huang Y. Maelstrom regulates spermatogenesis of the silkworm, Bombyx mori. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2019; 109:43-51. [PMID: 30970276 DOI: 10.1016/j.ibmb.2019.03.012] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2018] [Revised: 03/03/2019] [Accepted: 03/28/2019] [Indexed: 06/09/2023]
Abstract
The spermatogenesis of animal is essential for the reproduction and a very large number of genes participate in this procession. The Maelstrom (Mael) is identified essential for spermatogenesis in both Drosophila and mouse, though the mechanisms appear to differ. It was initially found that Mael gene is necessary for axis specification of oocytes in Drosophila, and recent studies suggested that Mael participates in the piRNA pathway. In this study, we obtained Bombyx mori Mael mutants by using a binary transgenic CRISPR/Cas9 system and analyzed the function of Mael in B. mori, a model lepidopteran insect. The results showed that BmMael is not necessary for piRNA pathway in the ovary of silkworm, whereas it might be essential for transposon elements (TEs) repression in testis. The BmMael mutation resulted in male sterility, and further analysis established that BmMael was essential for spermatogenesis. The spermatogenesis defects occurred in the elongation stage and resulted in nuclei concentration arrest. RNA-seq and qRT-PCR analyses demonstrated that spermatogenesis defects were associated with tight junctions and apoptosis. We also found that BmMael was not involved in the silkworm sex determination pathway. Our data provide insights into the biological function of BmMael in male spermatogenesis and might be useful for developing novel methods to control lepidopteron pests.
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Affiliation(s)
- Kai Chen
- Key Laboratory of Insect Developmental and Evolutionary Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, 200032, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Shuqing Chen
- Key Laboratory of Insect Developmental and Evolutionary Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, 200032, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Jun Xu
- Key Laboratory of Insect Developmental and Evolutionary Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, 200032, China
| | - Ye Yu
- Key Laboratory of Insect Developmental and Evolutionary Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, 200032, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Zulian Liu
- Key Laboratory of Insect Developmental and Evolutionary Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, 200032, China
| | - Anjiang Tan
- Key Laboratory of Insect Developmental and Evolutionary Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, 200032, China
| | - Yongping Huang
- Key Laboratory of Insect Developmental and Evolutionary Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, 200032, China.
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8
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Chang TH, Mattei E, Gainetdinov I, Colpan C, Weng Z, Zamore PD. Maelstrom Represses Canonical Polymerase II Transcription within Bi-directional piRNA Clusters in Drosophila melanogaster. Mol Cell 2019; 73:291-303.e6. [PMID: 30527661 PMCID: PMC6551610 DOI: 10.1016/j.molcel.2018.10.038] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2018] [Revised: 10/05/2018] [Accepted: 10/24/2018] [Indexed: 11/18/2022]
Abstract
In Drosophila, 23-30 nt long PIWI-interacting RNAs (piRNAs) direct the protein Piwi to silence germline transposon transcription. Most germline piRNAs derive from dual-strand piRNA clusters, heterochromatic transposon graveyards that are transcribed from both genomic strands. These piRNA sources are marked by the heterochromatin protein 1 homolog Rhino (Rhi), which facilitates their promoter-independent transcription, suppresses splicing, and inhibits transcriptional termination. Here, we report that the protein Maelstrom (Mael) represses canonical, promoter-dependent transcription in dual-strand clusters, allowing Rhi to initiate piRNA precursor transcription. Mael also represses promoter-dependent transcription at sites outside clusters. At some loci, Mael repression requires the piRNA pathway, while at others, piRNAs play no role. We propose that by repressing canonical transcription of individual transposon mRNAs, Mael helps Rhi drive non-canonical transcription of piRNA precursors without generating mRNAs encoding transposon proteins.
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MESH Headings
- Animals
- Argonaute Proteins/genetics
- Argonaute Proteins/metabolism
- Binding Sites
- Chromosomal Proteins, Non-Histone/genetics
- Chromosomal Proteins, Non-Histone/metabolism
- DNA Transposable Elements
- Drosophila Proteins/genetics
- Drosophila Proteins/metabolism
- Drosophila melanogaster/enzymology
- Drosophila melanogaster/genetics
- Gene Expression Regulation
- Promoter Regions, Genetic
- Protein Binding
- RNA Helicases/genetics
- RNA Helicases/metabolism
- RNA Polymerase II/genetics
- RNA Polymerase II/metabolism
- RNA, Messenger/biosynthesis
- RNA, Messenger/genetics
- RNA, Small Interfering/biosynthesis
- RNA, Small Interfering/genetics
- Transcription, Genetic
- RNA, Guide, CRISPR-Cas Systems
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Affiliation(s)
- Timothy H Chang
- RNA Therapeutics Institute and Howard Hughes Medical Institute, Worcester, MA, USA
| | - Eugenio Mattei
- Program in Bioinformatics and Integrative Biology, University of Massachusetts Medical School, 368 Plantation Street, Worcester, MA 01605, USA
| | - Ildar Gainetdinov
- RNA Therapeutics Institute and Howard Hughes Medical Institute, Worcester, MA, USA
| | - Cansu Colpan
- RNA Therapeutics Institute and Howard Hughes Medical Institute, Worcester, MA, USA
| | - Zhiping Weng
- Program in Bioinformatics and Integrative Biology, University of Massachusetts Medical School, 368 Plantation Street, Worcester, MA 01605, USA; Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, 364 Plantation Street, Worcester, MA 01605, USA.
| | - Phillip D Zamore
- RNA Therapeutics Institute and Howard Hughes Medical Institute, Worcester, MA, USA.
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9
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Li P, Chen X, Qin G, Yue D, Zhang Z, Ping Y, Wang D, Zhao X, Song M, Zhao Q, Li J, Liu S, Wang D, Zhang C, Lian J, Cao L, Li F, Huang L, Wang L, Yang L, Huang J, Li H, Zhang B, Zhang Y. Maelstrom Directs Myeloid-Derived Suppressor Cells to Promote Esophageal Squamous Cell Carcinoma Progression via Activation of the Akt1/RelA/IL8 Signaling Pathway. Cancer Immunol Res 2018; 6:1246-1259. [PMID: 30082413 DOI: 10.1158/2326-6066.cir-17-0415] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2017] [Revised: 01/17/2018] [Accepted: 07/31/2018] [Indexed: 12/15/2022]
Abstract
Maelstrom (MAEL) is a novel cancer/testis-associated gene, which is not only expressed in the male testicular germ cells among human normal tissues, but is also aberrantly expressed in various cancer tissues. In our study, MAEL was characterized as a tumor-promoting gene and was significantly associated with esophageal squamous cell carcinoma (ESCC) recurrence and unfavorable prognosis. Kaplan-Meier analysis showed that patients with high MAEL expression had a shorter survival time. Functional experiments showed that MAEL promoted tumor cell growth and inhibited cell apoptosis. These results prompted us to investigate the factors affecting the tumorigenicity of MAEL Further experimentation demonstrated that MAEL enhanced the expression of phosphorylated Akt1, with subsequent phosphorylation of nuclear factor kappa B (NF-κB) subunit RelA in tumor cells, and chemoattracted myeloid-derived suppressor cells (MDSCs) by upregulating interleukin-8 (IL8) to accelerate tumor progression in the tumor microenvironment. We also found that TGFβ secreted by MDSCs could upregulate MAEL by inducing Smad2/Smad3 phosphorylation. In summary, this study revealed a mechanism by which MAEL could upregulate IL8 through Akt1/RelA to direct MDSCs homing into the tumor, suggesting that MAEL could be an attractive therapeutic target and a prognostic marker against ESCC. Cancer Immunol Res; 6(10); 1246-59. ©2018 AACR.
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Affiliation(s)
- Pupu Li
- Biotherapy Center, the First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China.,Cancer Center, the First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China
| | - Xinfeng Chen
- Biotherapy Center, the First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China.,Cancer Center, the First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China
| | - Guohui Qin
- Biotherapy Center, the First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China.,Cancer Center, the First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China
| | - Dongli Yue
- Cancer Center, the First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China
| | - Zhen Zhang
- Biotherapy Center, the First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China
| | - Yu Ping
- Biotherapy Center, the First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China
| | - Dan Wang
- Biotherapy Center, the First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China.,Cancer Center, the First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China
| | - Xuan Zhao
- Biotherapy Center, the First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China
| | - Mengjia Song
- Biotherapy Center, the First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China.,Cancer Center, the First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China
| | - Qitai Zhao
- Biotherapy Center, the First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China.,Cancer Center, the First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China
| | - Jieyao Li
- Cancer Center, the First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China
| | - Shasha Liu
- Biotherapy Center, the First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China
| | - Dong Wang
- Biotherapy Center, the First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China.,Cancer Center, the First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China
| | - Chaoqi Zhang
- Biotherapy Center, the First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China.,Cancer Center, the First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China
| | - Jingyao Lian
- Biotherapy Center, the First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China
| | - Ling Cao
- Biotherapy Center, the First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China.,Cancer Center, the First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China
| | - Feng Li
- Biotherapy Center, the First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China
| | - Lan Huang
- Biotherapy Center, the First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China
| | - Liping Wang
- Cancer Center, the First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China
| | - Li Yang
- Biotherapy Center, the First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China
| | - Jianmin Huang
- Biotherapy Center, the First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China
| | - Hong Li
- Biotherapy Center, the First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China
| | - Bin Zhang
- Biotherapy Center, the First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China.,Department of Hematology/Oncology, School of Medicine, Northwestern University, Chicago, Illinois
| | - Yi Zhang
- Biotherapy Center, the First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China. .,Cancer Center, the First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China.,School of Life Sciences, Zhengzhou University, Zhengzhou, Henan, China.,Henan Key Laboratory for Tumor Immunology and Biotherapy, Zhengzhou, Henan, China
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10
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Zhang X, Ning Y, Xiao Y, Duan H, Qu G, Liu X, Du Y, Jiang D, Zhou J. MAEL contributes to gastric cancer progression by promoting ILKAP degradation. Oncotarget 2017; 8:113331-113344. [PMID: 29371914 PMCID: PMC5768331 DOI: 10.18632/oncotarget.22970] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2017] [Accepted: 11/13/2017] [Indexed: 12/13/2022] Open
Abstract
The cancer-testis gene MAEL is involved in the development and progression of bladder, liver and colorectal cancers. However, its role in other cancers is unclear. By systematically analyzing transcriptomics and genomics data from various cancer databases, we identified that the MAEL gene is aberrantly elevated in gastric cancer (GC) tissues and that its expression is strongly negatively correlated with DNA methylation (Pearson's correlation coefficient = −0.675). Survival analysis revealed that MAEL expression may serve as a prognostic marker for GC patients (overall survival: hazard ratio [HR] = 1.54, p = 1.2E-4; first progression: HR = 1.51, p = 8.7E-4). In vitro and in vivo experiments demonstrated that silencing MAEL expression in the GC cell lines HGC-27 and AGS inhibits proliferation, colony formation, migration, invasion and growth of xenograft tumors, whereas MAEL overexpression exerts the opposite effects in the normal gastric cell line GES-1. Mechanistically, MAEL promotes the lysosome-dependent degradation of the protein phosphatase ILKAP, leading to increased phosphorylation of its substrates (p38, CHK1 and RSK2). Moreover, adenovirus-mediated ILKAP overexpression reversed the oncogenic effects of MAEL in vitro and in vivo. Taken together, these results indicate that MAEL exerts its oncogenic function by promoting ILKAP degradation in the GC.
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Affiliation(s)
- Xing Zhang
- Key Laboratory of Protein Chemistry and Developmental Biology of The Ministry of Education, College of Life Science, Hunan Normal University, Changsha 410081, Hunan, China
| | - Yichong Ning
- Key Laboratory of Protein Chemistry and Developmental Biology of The Ministry of Education, College of Life Science, Hunan Normal University, Changsha 410081, Hunan, China
| | - Yuzhong Xiao
- College of Biology, Hunan University, Changsha 410082, Hunan, China
| | - Huaxin Duan
- The First Affiliated Hospital, Hunan Normal University, Changsha 410005, Hunan, China
| | - Guifang Qu
- The First Affiliated Hospital, Hunan Normal University, Changsha 410005, Hunan, China
| | - Xin Liu
- Key Laboratory of Protein Chemistry and Developmental Biology of The Ministry of Education, College of Life Science, Hunan Normal University, Changsha 410081, Hunan, China
| | - Yan Du
- Key Laboratory of Protein Chemistry and Developmental Biology of The Ministry of Education, College of Life Science, Hunan Normal University, Changsha 410081, Hunan, China
| | - Dejian Jiang
- Hunan Key Laboratory of Pharmacodynamics and Safety Evaluation of New Drugs, Changsha 410331, Hunan, China
| | - Jianlin Zhou
- Key Laboratory of Protein Chemistry and Developmental Biology of The Ministry of Education, College of Life Science, Hunan Normal University, Changsha 410081, Hunan, China
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11
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Pridöhl F, Weißkopf M, Koniszewski N, Sulzmaier A, Uebe S, Ekici AB, Schoppmeier M. Transcriptome sequencing reveals maelstrom as a novel target gene of the terminal-system in the red flour beetle Tribolium castaneum. Development 2017; 144:1339-1349. [DOI: 10.1242/dev.136853] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2016] [Accepted: 02/07/2017] [Indexed: 12/30/2022]
Abstract
Terminal regions of the Drosophila embryo are patterned by the localized activation of the Torso-RTK pathway, which promotes the down-regulation of Capicua. In the short-germ beetle Tribolium, the function of the terminal system appears to be rather different, as the pathway promotes axis elongation and in addition, is required for patterning the extraembryonic serosa at the anterior. Here we show that Torso signalling induces gene expression by relieving CAPICUA-mediated repression also in Tribolium. Given that the majority of Torso target genes remain to be identified, we established a differential gene-expression screen. A subset of 50 putative terminal target genes was screened for functions in early embryonic patterning. Of those, 13 genes show early terminal expression domains and also phenotypes were related to terminal patterning. Among others, we found the PIWI-interacting RNA factor Maelstrom to be crucial for early embryonic polarization. Tc-mael is required for proper serosal size regulation and head morphogenesis. Moreover, Tc-mael promotes growth-zone formation and axis elongation. Our results suggest that posterior patterning by Torso may be realized through Maelstrom depended activation of posterior wnt-domains.
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Affiliation(s)
- Fabian Pridöhl
- Department Biology, Developmental Biology Unit, Friedrich-Alexander-University Erlangen-Nuremberg, Staudtstr. 5, 91058, Erlangen, Germany, phone: ++49-9131-8528097, fax: ++49-9131-8528040
| | - Matthias Weißkopf
- Department Biology, Developmental Biology Unit, Friedrich-Alexander-University Erlangen-Nuremberg, Staudtstr. 5, 91058, Erlangen, Germany, phone: ++49-9131-8528097, fax: ++49-9131-8528040
| | - Nikolaus Koniszewski
- Department Biology, Developmental Biology Unit, Friedrich-Alexander-University Erlangen-Nuremberg, Staudtstr. 5, 91058, Erlangen, Germany, phone: ++49-9131-8528097, fax: ++49-9131-8528040
- present address: Institut für Medizinische Mikrobiologie und Krankenhaushygiene, Otto-von-Guericke-University, Leipziger Str. 44, 39120 Magdeburg, Germany, phone: ++49-391-6721834, fax: ++49-391-6713384
| | - Andreas Sulzmaier
- Department Biology, Developmental Biology Unit, Friedrich-Alexander-University Erlangen-Nuremberg, Staudtstr. 5, 91058, Erlangen, Germany, phone: ++49-9131-8528097, fax: ++49-9131-8528040
| | - Steffen Uebe
- Institute of Human Genetics, Friedrich-Alexander-University Erlangen-Nuremberg, Schwabachanlage 10, 91054 Erlangen, Germany, phone: ++49-9131 8522318, fax: ++49-9131 85-23232
| | - Arif B. Ekici
- Institute of Human Genetics, Friedrich-Alexander-University Erlangen-Nuremberg, Schwabachanlage 10, 91054 Erlangen, Germany, phone: ++49-9131 8522318, fax: ++49-9131 85-23232
| | - Michael Schoppmeier
- Department Biology, Developmental Biology Unit, Friedrich-Alexander-University Erlangen-Nuremberg, Staudtstr. 5, 91058, Erlangen, Germany, phone: ++49-9131-8528097, fax: ++49-9131-8528040
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12
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Li XD, Zhang JX, Jiang LJ, Wang FW, Liu LL, Liao YJ, Jin XH, Chen WH, Chen X, Guo SJ, Zhou FJ, Zeng YX, Guan XY, Liu ZW, Xie D. Overexpression of maelstrom promotes bladder urothelial carcinoma cell aggressiveness by epigenetically downregulating MTSS1 through DNMT3B. Oncogene 2016; 35:6281-6292. [PMID: 27181205 DOI: 10.1038/onc.2016.165] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2015] [Revised: 02/29/2016] [Accepted: 03/31/2016] [Indexed: 12/15/2022]
Abstract
We have recently identified and characterized a novel oncogene, maelstrom (MAEL) from 1q24, in the pathogenesis of hepatocellular carcinoma. In this study, MAEL was investigated for its oncogenic role in urothelial carcinoma of the bladder (UCB) tumorigenesis/aggressiveness and underlying molecular mechanisms. Here, we report that overexpression of MAEL in UCB is important in the acquisition of an aggressive and/or poor prognostic phenotype. In UCB cell lines, knockdown of MAEL by short hairpin RNA is sufficient to inhibit cell growth, invasiveness/metastasis and suppressed epithelial-mesenchymal transition (EMT), whereas ectopic overexpression of MAEL promoted cell growth, invasive and/or metastatic capacity and enhanced EMT both in vitro and in vivo. We further demonstrate that MAEL could induce UCB cell EMT by downregulating a critical downstream target, the metastasis suppressor 1 (MTSS1) gene, ultimately leading to an increased invasiveness of cancer cells. Notably, overexpression of MAEL in UCB cells substantially enhanced the enrichment of DNA methyltrans-ferase (DNMT)3B and histone deacetylase (HDAC)1/2 on the promoter of the MTSS1, and thereby epigenetically suppressing the MTSS1 transcription. Downregulation of MTSS1 by MAEL in UCB cells is partially dependent on DNMT3B. Furthermore, we identify that beside the gene amplification of MAEL, miR-186 is a key negative regulator of MAEL and downregulation of miR-186 is another important mechanism for MAEL overexpression in UCBs. These data suggest that overexpression of MAEL, caused by gene amplification and/or decreased miR-186, has a critical oncogenic role in UCB pathogenesis by downregulation of MTSS1, and MAEL could be used as a novel prognostic marker and/or effective therapeutic target for human UCB.
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Affiliation(s)
- X-D Li
- State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, China
- Department of Urology, Sun Yat-sen University Cancer Center, Guangzhou, China
| | - J-X Zhang
- State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, China
- Department of Oncology, The First Affiliated Hospital, Sun Yat-Sen University, Guangzhou, China
| | - L-J Jiang
- State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, China
- Department of Urology, Sun Yat-sen University Cancer Center, Guangzhou, China
| | - F-W Wang
- State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, China
| | - L-L Liu
- State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, China
| | - Y-J Liao
- State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, China
| | - X-H Jin
- State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, China
| | - W-H Chen
- State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, China
| | - X Chen
- State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, China
- Department of Urology, Sun Yat-sen University Cancer Center, Guangzhou, China
| | - S-J Guo
- State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, China
- Department of Urology, Sun Yat-sen University Cancer Center, Guangzhou, China
| | - F-J Zhou
- State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, China
- Department of Urology, Sun Yat-sen University Cancer Center, Guangzhou, China
| | - Y-X Zeng
- State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, China
| | - X-Y Guan
- State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, China
- Department of Clinical Oncology, The University of Hong Kong, Hong Kong, China
| | - Z-W Liu
- State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, China
- Department of Urology, Sun Yat-sen University Cancer Center, Guangzhou, China
| | - D Xie
- State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, China
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13
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Li Q, Wei P, Huang B, Xu Y, Li X, Li Y, Cai S, Li D. MAEL expression links epithelial-mesenchymal transition and stem cell properties in colorectal cancer. Int J Cancer 2016; 139:2502-11. [PMID: 27537253 DOI: 10.1002/ijc.30388] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2016] [Revised: 08/03/2016] [Accepted: 08/10/2016] [Indexed: 12/29/2022]
Abstract
MAEL plays a central role during spermatogenesis by repressing transposable elements and preventing their mobilisation, however, its role on cancers is unclear. In this study, MAEL expression was analysed in a tissue microarray containing 185 samples of primary colon cancer tumor samples and human colon cancer cell lines. The effect of MAEL on cell proliferation, tumorigenesis, metastasis and drug resistance was examined in vitro and in vivo. Immunoprecipitation assay, confocal immunofluorescent analysis and luciferase assay were used for mechanism study. As results, MAEL was significantly upregulated in colon cancer patient tissue samples, and elevated MAEL protein levels positively correlated with overall survival and disease free survival of colon cancer patients. Using in vitro and in vivo models, we demonstrated that MAEL expression was correlated with cell proliferation, invasion and drug resistance of colon cancer cells by inducing epithelial-mesenchymal transition and stemness characteristics. Mechanistically, our study demonstrated that MAEL interacts with Snail and inhibit E-cadherin promoter activity. Collectively, MAEL is an oncogene that plays an important role in the development and progression of colon cancer, which may be a novel potential therapeutic target for colon cancer.
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Affiliation(s)
- Qingguo Li
- Department of Colorectal Surgery, Fudan University Shanghai Cancer Center, Shanghai, 200032, China.,Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, 200032, China
| | - Ping Wei
- Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, 200032, China.,Department of Pathology, Fudan University Shanghai Cancer Center, Shanghai, 200032, China
| | - Ben Huang
- Department of Colorectal Surgery, Fudan University Shanghai Cancer Center, Shanghai, 200032, China.,Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, 200032, China
| | - Ye Xu
- Department of Colorectal Surgery, Fudan University Shanghai Cancer Center, Shanghai, 200032, China.,Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, 200032, China
| | - Xinxiang Li
- Department of Colorectal Surgery, Fudan University Shanghai Cancer Center, Shanghai, 200032, China.,Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, 200032, China
| | - Yaqi Li
- Department of Colorectal Surgery, Fudan University Shanghai Cancer Center, Shanghai, 200032, China.,Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, 200032, China
| | - Sanjun Cai
- Department of Colorectal Surgery, Fudan University Shanghai Cancer Center, Shanghai, 200032, China. .,Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, 200032, China.
| | - Dawei Li
- Department of Colorectal Surgery, Fudan University Shanghai Cancer Center, Shanghai, 200032, China. .,Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, 200032, China.
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14
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Abstract
The adult mammalian ovary is devoid of definitive germline stem cells. As such, female reproductive senescence largely results from the depletion of a finite ovarian follicle pool that is produced during embryonic development. Remarkably, the crucial nature and regulation of follicle assembly and survival during embryogenesis is just coming into focus. This developmental pathway involves the coordination of meiotic progression and the breakdown of germ cell cysts into individual oocytes housed within primordial follicles. Recent evidence also indicates that genetic and environmental factors can specifically perturb primordial follicle assembly. Here, we review the cellular and molecular mechanisms by which the mammalian ovarian reserve is established, highlighting the presence of a crucial checkpoint that allows survival of only the highest-quality oocytes.
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Affiliation(s)
- Kathryn J Grive
- Brown University, MCB Graduate Program, Providence, RI 02912, USA
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15
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Fang Y, Feng M, Han B, Qi Y, Hu H, Fan P, Huo X, Meng L, Li J. Proteome Analysis Unravels Mechanism Underling the Embryogenesis of the Honeybee Drone and Its Divergence with the Worker (Apis mellifera lingustica). J Proteome Res 2015; 14:4059-71. [PMID: 26260241 DOI: 10.1021/acs.jproteome.5b00625] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The worker and drone bees each contain a separate diploid and haploid genetic makeup, respectively. Mechanisms regulating the embryogenesis of the drone and its mechanistic difference with the worker are still poorly understood. The proteomes of the two embryos at three time-points throughout development were analyzed by applying mass spectrometry-based proteomics. We identified 2788 and 2840 proteins in the worker and drone embryos, respectively. The age-dependent proteome driving the drone embryogenesis generally follows the worker's. The two embryos however evolve a distinct proteome setting to prime their respective embryogenesis. The strongly expressed proteins and pathways related to transcriptional-translational machinery and morphogenesis at 24 h drone embryo relative to the worker, illustrating the earlier occurrence of morphogenesis in the drone than worker. These morphogenesis differences remain through to the middle-late stage in the two embryos. The two embryos employ distinct antioxidant mechanisms coinciding with the temporal-difference organogenesis. The drone embryo's strongly expressed cytoskeletal proteins signify key roles to match its large body size. The RNAi induced knockdown of the ribosomal protein offers evidence for the functional investigation of gene regulating of honeybee embryogenesis. The data significantly expand novel regulatory mechanisms governing the embryogenesis, which is potentially important for honeybee and other insects.
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Affiliation(s)
- Yu Fang
- Institute of Apicultural Research/Key Laboratory of Pollinating Insect Biology, Ministry of Agriculture, Chinese Academy of Agricultural Sciences , Beijing, 100093, China
| | - Mao Feng
- Institute of Apicultural Research/Key Laboratory of Pollinating Insect Biology, Ministry of Agriculture, Chinese Academy of Agricultural Sciences , Beijing, 100093, China
| | - Bin Han
- Institute of Apicultural Research/Key Laboratory of Pollinating Insect Biology, Ministry of Agriculture, Chinese Academy of Agricultural Sciences , Beijing, 100093, China
| | - Yuping Qi
- Institute of Apicultural Research/Key Laboratory of Pollinating Insect Biology, Ministry of Agriculture, Chinese Academy of Agricultural Sciences , Beijing, 100093, China
| | - Han Hu
- Institute of Apicultural Research/Key Laboratory of Pollinating Insect Biology, Ministry of Agriculture, Chinese Academy of Agricultural Sciences , Beijing, 100093, China
| | - Pei Fan
- Institute of Apicultural Research/Key Laboratory of Pollinating Insect Biology, Ministry of Agriculture, Chinese Academy of Agricultural Sciences , Beijing, 100093, China
| | - Xinmei Huo
- Institute of Apicultural Research/Key Laboratory of Pollinating Insect Biology, Ministry of Agriculture, Chinese Academy of Agricultural Sciences , Beijing, 100093, China
| | - Lifeng Meng
- Institute of Apicultural Research/Key Laboratory of Pollinating Insect Biology, Ministry of Agriculture, Chinese Academy of Agricultural Sciences , Beijing, 100093, China
| | - Jianke Li
- Institute of Apicultural Research/Key Laboratory of Pollinating Insect Biology, Ministry of Agriculture, Chinese Academy of Agricultural Sciences , Beijing, 100093, China
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16
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Matsumoto N, Sato K, Nishimasu H, Namba Y, Miyakubi K, Dohmae N, Ishitani R, Siomi H, Siomi MC, Nureki O. Crystal Structure and Activity of the Endoribonuclease Domain of the piRNA Pathway Factor Maelstrom. Cell Rep 2015; 11:366-75. [PMID: 25865890 DOI: 10.1016/j.celrep.2015.03.030] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2014] [Revised: 02/19/2015] [Accepted: 03/10/2015] [Indexed: 01/09/2023] Open
Abstract
PIWI-interacting RNAs (piRNAs) protect the genome from transposons in animal gonads. Maelstrom (Mael) is an evolutionarily conserved protein, composed of a high-mobility group (HMG) domain and a MAEL domain, and is essential for piRNA-mediated transcriptional transposon silencing in various species, such as Drosophila and mice. However, its structure and biochemical function have remained elusive. Here, we report the crystal structure of the MAEL domain from Drosophila melanogaster Mael, at 1.6 Å resolution. The structure reveals that the MAEL domain has an RNase H-like fold but lacks canonical catalytic residues conserved among RNase H-like superfamily nucleases. Our biochemical analyses reveal that the MAEL domain exhibits single-stranded RNA (ssRNA)-specific endonuclease activity. Our cell-based analyses further indicate that ssRNA cleavage activity appears dispensable for piRNA-mediated transcriptional transposon silencing in Drosophila. Our findings provide clues toward understanding the multiple roles of Mael in the piRNA pathway.
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Affiliation(s)
- Naoki Matsumoto
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo 113-0032, Japan
| | - Kaoru Sato
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo 113-0032, Japan
| | - Hiroshi Nishimasu
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo 113-0032, Japan; JST, PRESTO, Tokyo 113-0032, Japan
| | - Yurika Namba
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo 113-0032, Japan
| | - Kana Miyakubi
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo 113-0032, Japan
| | - Naoshi Dohmae
- Biomolecular Characterization Team and CREST/JST, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Ryuichiro Ishitani
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo 113-0032, Japan
| | - Haruhiko Siomi
- Department of Molecular Biology, Keio University School of Medicine, Tokyo 160-8582, Japan
| | - Mikiko C Siomi
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo 113-0032, Japan.
| | - Osamu Nureki
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo 113-0032, Japan.
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17
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Sato K, Siomi MC. Functional and structural insights into the piRNA factor Maelstrom. FEBS Lett 2015; 589:1688-93. [DOI: 10.1016/j.febslet.2015.03.023] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2015] [Accepted: 03/19/2015] [Indexed: 10/23/2022]
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18
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Huang F, Paulson A, Dutta A, Venkatesh S, Smolle M, Abmayr SM, Workman JL. Histone acetyltransferase Enok regulates oocyte polarization by promoting expression of the actin nucleation factor spire. Genes Dev 2015; 28:2750-63. [PMID: 25512562 PMCID: PMC4265678 DOI: 10.1101/gad.249730.114] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
KAT6 histone acetyltransferases (HATs) are highly conserved in eukaryotes and have been shown to play important roles in transcriptional regulation. Here, we demonstrate that the Drosophila KAT6 Enok acetylates histone H3 Lys 23 (H3K23) in vitro and in vivo. Mutants lacking functional Enok exhibited defects in the localization of Oskar (Osk) to the posterior end of the oocyte, resulting in loss of germline formation and abdominal segments in the embryo. RNA sequencing (RNA-seq) analysis revealed that spire (spir) and maelstrom (mael), both required for the posterior localization of Osk in the oocyte, were down-regulated in enok mutants. Chromatin immunoprecipitation showed that Enok is localized to and acetylates H3K23 at the spir and mael genes. Furthermore, Gal4-driven expression of spir in the germline can largely rescue the defective Osk localization in enok mutant ovaries. Our results suggest that the Enok-mediated H3K23 acetylation (H3K23Ac) promotes the expression of spir, providing a specific mechanism linking oocyte polarization to histone modification.
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Affiliation(s)
- Fu Huang
- Stowers Institute for Medical Research, Kansas City, Missouri 64110, USA
| | - Ariel Paulson
- Stowers Institute for Medical Research, Kansas City, Missouri 64110, USA
| | - Arnob Dutta
- Stowers Institute for Medical Research, Kansas City, Missouri 64110, USA
| | | | - Michaela Smolle
- Stowers Institute for Medical Research, Kansas City, Missouri 64110, USA
| | - Susan M Abmayr
- Stowers Institute for Medical Research, Kansas City, Missouri 64110, USA; Department of Anatomy and Cell Biology, University of Kansas Medical Center, Kansas City, Kansas 66160, USA
| | - Jerry L Workman
- Stowers Institute for Medical Research, Kansas City, Missouri 64110, USA;
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19
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Patil VS, Anand A, Chakrabarti A, Kai T. The Tudor domain protein Tapas, a homolog of the vertebrate Tdrd7, functions in the piRNA pathway to regulate retrotransposons in germline of Drosophila melanogaster. BMC Biol 2014; 12:61. [PMID: 25287931 PMCID: PMC4210518 DOI: 10.1186/s12915-014-0061-9] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2014] [Accepted: 07/25/2014] [Indexed: 01/21/2023] Open
Abstract
Background Piwi-interacting RNAs (piRNAs) are a special class of small RNAs that provide defense against transposable elements in animal germline cells. In Drosophila, germline piRNAs are thought to be processed at a unique perinuclear structure, the nuage, that houses piRNA pathway proteins including the Piwi clade of Argonaute family proteins, along with several Tudor domain proteins, RNA helicases and nucleases. We previously demonstrated that Tudor domain protein Tejas (Tej), an ortholog of vertebrate Tdrd5, is an important component of the piRNA pathway. Results In the current study, we identified the paralog of the Drosophila tej gene, tapas (tap), which is an ortholog of vertebrate Tdrd7. Like Tej, Tap is localized at the nuage. Alone, tap loss leads to a mild increase in transposon expression and decrease in piRNAs targeting transposons expressed in the germline. The tap gene genetically interacts with other piRNA pathway genes and we also show that Tap physically interacts with piRNA pathway components, such as Piwi family proteins Aubergine and Argonaute3 and the RNA helicases Spindle-E and Vasa. Together with tej, tap is required for survival of germline cells during early stages and for polarity formation. We further observed that loss of tej and tap together results in more severe defects in the piRNA pathway in germline cells compared to single mutants: the double-mutant ovaries exhibit mis-localization of piRNA pathway components and significantly greater reduction of piRNAs against transposons predominantly expressed in germline compared to single mutants. The single or double mutants did not have any reduction in piRNAs mapping to transposons predominantly expressed in gonadal somatic cells or those derived from unidirectional clusters such as flamenco. Consistently, the loss of both tej and tap function resulted in mis-localization of Piwi in germline cells, whereas Piwi remained localized to the nucleus in somatic cells. Conclusions Our observations suggest that tej and tap work together for germline maintenance. tej and tap also function in a synergistic manner to maintain examined piRNA components at the perinuclear nuage and for piRNA production in Drosophila germline cells. Electronic supplementary material The online version of this article (doi:10.1186/s12915-014-0061-9) contains supplementary material, which is available to authorized users.
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20
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A genetic screen based on in vivo RNA imaging reveals centrosome-independent mechanisms for localizing gurken transcripts in Drosophila. G3-GENES GENOMES GENETICS 2014; 4:749-60. [PMID: 24531791 PMCID: PMC4059244 DOI: 10.1534/g3.114.010462] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
We have screened chromosome arm 3L for ethyl methanesulfonate−induced mutations that disrupt localization of fluorescently labeled gurken (grk) messenger (m)RNA, whose transport along microtubules establishes both major body axes of the developing Drosophila oocyte. Rapid identification of causative mutations by single-nucleotide polymorphism recombinational mapping and whole-genomic sequencing allowed us to define nine complementation groups affecting grk mRNA localization and other aspects of oogenesis, including alleles of elg1, scaf6, quemao, nudE, Tsc2/gigas, rasp, and Chd5/Wrb, and several null alleles of the armitage Piwi-pathway gene. Analysis of a newly induced kinesin light chain allele shows that kinesin motor activity is required for both efficient grk mRNA localization and oocyte centrosome integrity. We also show that initiation of the dorsoanterior localization of grk mRNA precedes centrosome localization, suggesting that microtubule self-organization contributes to breaking axial symmetry to generate a unique dorsoventral axis.
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Liu L, Dai Y, Chen J, Zeng T, Li Y, Chen L, Zhu YH, Li J, Li Y, Ma S, Xie D, Yuan YF, Guan XY. Maelstrom promotes hepatocellular carcinoma metastasis by inducing epithelial-mesenchymal transition by way of Akt/GSK-3β/Snail signaling. Hepatology 2014; 59:531-43. [PMID: 23929794 DOI: 10.1002/hep.26677] [Citation(s) in RCA: 103] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/10/2013] [Accepted: 08/04/2013] [Indexed: 12/13/2022]
Abstract
UNLABELLED Amplification of 1q is one of the most frequent chromosomal alterations in human hepatocellular carcinoma (HCC). In this study we identified and characterized a novel oncogene, Maelstrom (MAEL), at 1q24. Amplification and overexpression of MAEL was frequently detected in HCCs and significantly associated with HCC recurrence (P = 0.031) and poor outcome (P = 0.001). Functional study demonstrated that MAEL promoted cell growth, cell migration, and tumor formation in nude mice, all of which were effectively inhibited when MAEL was silenced with short hairpin RNA (shRNAs). Further study found that MAEL enhanced AKT activity with subsequent GSK-3β phosphorylation and Snail stabilization, finally inducing epithelial-mesenchymal transition (EMT) and promoting tumor invasion and metastasis. In addition, MAEL up-regulated various stemness-related genes, multidrug resistance genes, and cancer stem cell (CSC) surface markers at the messenger RNA (mRNA) level. Functional study demonstrated that overexpression of MAEL increased self-renewal, chemoresistance, and tumor metastasis. CONCLUSION MAEL is an oncogene that plays an important role in the development and progression of HCC by inducing EMT and enhancing the stemness of HCC.
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Affiliation(s)
- Lulu Liu
- State Key Laboratory of Oncology in South China, Sun Yat-Sen University Cancer Center, Guangzhou, China
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22
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Lim SL, Tsend-Ayush E, Kortschak RD, Jacob R, Ricciardelli C, Oehler MK, Grützner F. Conservation and expression of PIWI-interacting RNA pathway genes in male and female adult gonad of amniotes. Biol Reprod 2013; 89:136. [PMID: 24108303 DOI: 10.1095/biolreprod.113.111211] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
The PIWI-interacting RNA (piRNA) pathway is essential for germline development and transposable element repression. Key elements of this pathway are members of the piRNA-binding PIWI/Argonaute protein family and associated factors (e.g., VASA, MAELSTROM, and TUDOR domain proteins). PIWI-interacting RNAs have been identified in mouse testis and oocytes, but information about the expression of the different piRNA pathway genes, in particular in the mammalian ovary, remains incomplete. We investigated the evolution and expression of piRNA pathway genes in gonads of amniote species (chicken, platypus, and mouse). Database searches confirm a high level of conservation and revealed lineage-specific gain and loss of Piwi genes in vertebrates. Expression analysis in mammals shows that orthologs of Piwi-like (Piwil) genes, Mael (Maelstrom), Mvh (mouse vasa homolog), and Tdrd1 (Tudor domain-containing protein 1) are expressed in platypus adult testis. In contrast to mouse, Piwil4 is expressed in platypus and human adult testis. We found evidence for Mael and Piwil2 expression in mouse Sertoli cells. Importantly, we show mRNA expression of Piwil2, Piwil4, and Mael in oocytes and supporting cells of human, mouse, and platypus ovary. We found no Piwil1 expression in mouse and chicken ovary. The conservation of gene expression in somatic parts of the gonad and germ cells of species that diverged over 800 million yr ago indicates an important role in adult male and female gonad.
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Affiliation(s)
- Shu Ly Lim
- The Robinson Institute, School of Molecular and Biomedical Science, The University of Adelaide, Adelaide, South Australia, Australia
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23
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YUAN LIQIN, XIAO YUZHONG, ZHOU QIUZHI, YUAN DONGMEI, WU BAIPING, CHEN GANNONG, ZHOU JIANLIN. Proteomic analysis reveals that MAEL, a component of nuage, interacts with stress granule proteins in cancer cells. Oncol Rep 2013; 31:342-50. [DOI: 10.3892/or.2013.2836] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2013] [Accepted: 10/21/2013] [Indexed: 11/06/2022] Open
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24
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A mosaic genetic screen for genes involved in the early steps of Drosophila oogenesis. G3-GENES GENOMES GENETICS 2013; 3:409-25. [PMID: 23450845 PMCID: PMC3583450 DOI: 10.1534/g3.112.004747] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/23/2012] [Accepted: 12/27/2012] [Indexed: 12/15/2022]
Abstract
The first hours of Drosophila embryogenesis rely exclusively on maternal information stored within the egg during oogenesis. The formation of the egg chamber is thus a crucial step for the development of the future adult. It has emerged that many key developmental decisions are made during the very first stages of oogenesis. We performed a clonal genetic screen on the left arm of chromosome 2 for mutations affecting early oogenesis. During the first round of screening, we scored for defects in egg chambers morphology as an easy read-out of early abnormalities. In a second round of screening, we analyzed the localization of centrosomes and Orb protein within the oocyte, the position of the oocyte within the egg chamber, and the progression through meiosis. We have generated a collection of 71 EMS-induced mutants that affect oocyte determination, polarization, or localization. We also recovered mutants affecting the number of germline cyst divisions or the differentiation of follicle cells. Here, we describe the analysis of nine complementation groups and eight single alleles. We mapped several mutations and identified alleles of Bicaudal-D, lethal(2) giant larvae, kuzbanian, GDP-mannose 4,6-dehydratase, tho2, and eiF4A. We further report the molecular identification of two alleles of the Drosophila homolog of Che-1/AATF and demonstrate its antiapoptotic activity in vivo. This collection of mutants will be useful to investigate further the early steps of Drosophila oogenesis at a genetic level.
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Takebe M, Onohara Y, Yokota S. Expression of MAEL in nuage and non-nuage compartments of rat spermatogenic cells and colocalization with DDX4, DDX25 and MIWI. Histochem Cell Biol 2013; 140:169-81. [PMID: 23412502 DOI: 10.1007/s00418-012-1067-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/12/2012] [Indexed: 10/27/2022]
Abstract
The functions of MAELSTROM protein (MAEL) in spermatogenesis are gradually being identified but the precise distribution of MAEL in spermatogenic cells during spermatogenesis has not yet been mapped. We studied the expression of MAEL in rat testis by immunofluorescence and immunoelectron microscopy (IEM). Immunofluorescence staining showed that MAEL was localized in intermitochondrial cement, irregularly-shaped perinuclear granules and satellite bodies of pachytene spermatocytes, and in chromatoid bodies of spermatids. The SBs appeared exclusively in pachytene spermatocytes at stages IX-X and were stained strongly for MAEL. In step 12-19 spermatids, many granules stained for MAEL but not DDX4. These granules were confirmed to be non-nuage structures, including mitochondria-associated granules, reticulated body, granulated body by IEM. In the neck region of late spermatids and sperm, MAEL-positive small granules were found. MAEL is colocalized with MIWI in nuage and non-nuage. The results suggest that MAEL seems to function in nuage and non-nuage structures and interacts with MIWI.
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Affiliation(s)
- Miki Takebe
- Division of Functional Morphology, Faculty of Pharmaceutical Sciences, Nagasaki International University, Sasebo, Nagasaki, Japan
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26
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Abstract
Hybrids of two Drosophila species show transposable element derepression and piRNA pathway malfunction, revealing adaptive evolution of piRNA pathway components. The Piwi-interacting RNA (piRNA) pathway defends the germline of animals from the deleterious activity of selfish transposable elements (TEs) through small-RNA mediated silencing. Adaptation to novel invasive TEs is proposed to occur by incorporating their sequences into the piRNA pool that females produce and deposit into their eggs, which then propagates immunity against specific TEs to future generations. In support of this model, the F1 offspring of crosses between strains of the same Drosophila species sometimes suffer from germline derepression of paternally inherited TE families, caused by a failure of the maternal strain to produce the piRNAs necessary for their regulation. However, many protein components of the Drosophila piRNA pathway exhibit signatures of positive selection, suggesting that they also contribute to the evolution of host genome defense. Here we investigate piRNA pathway function and TE regulation in the F1 hybrids of interspecific crosses between D. melanogaster and D. simulans and compare them with intraspecific control crosses of D. melanogaster. We confirm previous reports showing that intraspecific crosses are characterized by derepression of paternally inherited TE families that are rare or absent from the maternal genome and piRNA pool, consistent with the role of maternally deposited piRNAs in shaping TE silencing. In contrast to the intraspecific cross, we discover that interspecific hybrids are characterized by widespread derepression of both maternally and paternally inherited TE families. Furthermore, the pattern of derepression of TE families in interspecific hybrids cannot be attributed to their paucity or absence from the piRNA pool of the maternal species. Rather, we demonstrate that interspecific hybrids closely resemble piRNA effector-protein mutants in both TE misregulation and aberrant piRNA production. We suggest that TE derepression in interspecific hybrids largely reflects adaptive divergence of piRNA pathway genes rather than species-specific differences in TE-derived piRNAs. Eukaryotic genomes contain large quantities of transposable elements (TEs), short self-replicating DNA sequences that can move within the genome. The selfish replication of TEs has potentially drastic consequences for the host, such as disruption of gene function, induction of sterility, and initiation or exacerbation of some cancers. Like the adaptive immune system that defends our bodies against pathogens, the Piwi-interacting RNA (piRNA) pathway defends animal genomes against the harmful effects of TEs. Fundamental to piRNA-mediated defense is the production of small noncoding RNAs that act like antibodies to target replicating TEs for destruction by piRNA-effector proteins. piRNAs are expected to diverge rapidly between species in response to genome infection by increasingly disparate TEs. Here, we tested this hypothesis by examining how differences in piRNAs between two species of fruit fly relate to TE “immunity” in their hybrid offspring. Because piRNAs are maternally deposited, we expected excessive replication of paternal TEs in hybrids. Surprisingly, we observe increased activity of both maternal and paternal TEs, together with defects in piRNA production that are reminiscent of piRNA effector-protein mutants. Our observations reveal that piRNA effector-proteins do not function properly in hybrids, and we propose that adaptive evolution among piRNA effector-proteins contributes to host genome defense and leads to the functional incompatibilities that we observe in hybrids.
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MESH Headings
- Adaptation, Biological
- Animals
- Animals, Genetically Modified/genetics
- Animals, Genetically Modified/metabolism
- Argonaute Proteins/genetics
- Argonaute Proteins/metabolism
- Crosses, Genetic
- DNA Transposable Elements
- Drosophila/genetics
- Drosophila/metabolism
- Drosophila Proteins/genetics
- Drosophila Proteins/metabolism
- Evolution, Molecular
- Female
- Genetic Complementation Test
- Genome, Insect
- Hybridization, Genetic
- Immunohistochemistry
- Inheritance Patterns
- Male
- Mutation
- Ovary/cytology
- Ovary/metabolism
- Peptide Initiation Factors/genetics
- Peptide Initiation Factors/metabolism
- Phenotype
- RNA Interference
- RNA, Small Interfering/genetics
- RNA, Small Interfering/metabolism
- Selection, Genetic
- Species Specificity
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Affiliation(s)
- Erin S. Kelleher
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York, United States of America
- * E-mail: (ESK); (DAB)
| | | | - Daniel A. Barbash
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York, United States of America
- * E-mail: (ESK); (DAB)
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27
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Abstract
Translational regulation plays an essential role in many phases of the Drosophila life cycle. During embryogenesis, specification of the developing body pattern requires co-ordination of the translation of oskar, gurken and nanos mRNAs with their subcellular localization. In addition, dosage compensation is controlled by Sex-lethal-mediated translational regulation while dFMR1 (the Drosophila homologue of the fragile X mental retardation protein) controls translation of various mRNAs which function in the nervous system. Here we describe some of the mechanisms that are utilized to regulate these various processes. Our review highlights the complexity that can be involved with multiple factors employing different mechanisms to control the translation of a single mRNA.
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Affiliation(s)
- James E Wilhelm
- Department of Embryology, Carnegie Institution of Washington, Baltimore, MD 21210, USA
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28
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Sato K, Nishida KM, Shibuya A, Siomi MC, Siomi H. Maelstrom coordinates microtubule organization during Drosophila oogenesis through interaction with components of the MTOC. Genes Dev 2011; 25:2361-73. [PMID: 22085963 DOI: 10.1101/gad.174110.111] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
The establishment of body axes in multicellular organisms requires accurate control of microtubule polarization. Mutations in Drosophila PIWI-interacting RNA (piRNA) pathway genes often disrupt the axes of the oocyte. This results from the activation of the DNA damage checkpoint factor Checkpoint kinase 2 (Chk2) due to transposon derepression. A piRNA pathway gene, maelstrom (mael), is critical for the establishment of oocyte polarity in the developing egg chamber during Drosophila oogenesis. We show that Mael forms complexes with microtubule-organizing center (MTOC) components, including Centrosomin, Mini spindles, and γTubulin. We also show that Mael colocalizes with αTubulin and γTubulin to centrosomes in dividing cyst cells and follicle cells. MTOC components mislocalize in mael mutant germarium and egg chambers, leading to centrosome migration defects. During oogenesis, the loss of mael affects oocyte determination and induces egg chamber fusion. Finally, we show that the axis specification defects in mael mutants are not suppressed by a mutation in mnk, which encodes a Chk2 homolog. These findings suggest a model in which Mael serves as a platform that nucleates other MTOC components to form a functional MTOC in early oocyte development, which is independent of Chk2 activation and DNA damage signaling.
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Affiliation(s)
- Kaoru Sato
- Department of Molecular Biology, Keio University School of Medicine, Tokyo, Japan
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29
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Bonnet A, Bevilacqua C, Benne F, Bodin L, Cotinot C, Liaubet L, Sancristobal M, Sarry J, Terenina E, Martin P, Tosser-Klopp G, Mandon-Pepin B. Transcriptome profiling of sheep granulosa cells and oocytes during early follicular development obtained by laser capture microdissection. BMC Genomics 2011; 12:417. [PMID: 21851638 PMCID: PMC3166951 DOI: 10.1186/1471-2164-12-417] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2011] [Accepted: 08/18/2011] [Indexed: 12/31/2022] Open
Abstract
Background Successful achievement of early folliculogenesis is crucial for female reproductive function. The process is finely regulated by cell-cell interactions and by the coordinated expression of genes in both the oocyte and in granulosa cells. Despite many studies, little is known about the cell-specific gene expression driving early folliculogenesis. The very small size of these follicles and the mixture of types of follicles within the developing ovary make the experimental study of isolated follicular components very difficult. The recently developed laser capture microdissection (LCM) technique coupled with microarray experiments is a promising way to address the molecular profile of pure cell populations. However, one main challenge was to preserve the RNA quality during the isolation of single cells or groups of cells and also to obtain sufficient amounts of RNA. Using a new LCM method, we describe here the separate expression profiles of oocytes and follicular cells during the first stages of sheep folliculogenesis. Results We developed a new tissue fixation protocol ensuring efficient single cell capture and RNA integrity during the microdissection procedure. Enrichment in specific cell types was controlled by qRT-PCR analysis of known genes: six oocyte-specific genes (SOHLH2, MAEL, MATER, VASA, GDF9, BMP15) and three granulosa cell-specific genes (KL, GATA4, AMH). A global gene expression profile for each follicular compartment during early developmental stages was identified here for the first time, using a bovine Affymetrix chip. Most notably, the granulosa cell dataset is unique to date. The comparison of oocyte vs. follicular cell transcriptomes revealed 1050 transcripts specific to the granulosa cell and 759 specific to the oocyte. Functional analyses allowed the characterization of the three main cellular events involved in early folliculogenesis and confirmed the relevance and potential of LCM-derived RNA. Conclusions The ovary is a complex mixture of different cell types. Distinct cell populations need therefore to be analyzed for a better understanding of their potential interactions. LCM and microarray analysis allowed us to identify novel gene expression patterns in follicular cells at different stages and in oocyte populations.
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Affiliation(s)
- Agnes Bonnet
- INRA, UMR444 Génétique Cellulaire, Auzeville, Castanet-Tolosan, France.
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30
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Sokolova OA, Yakushev EY, Stolyarenko AD, Mikhaleva EA, Gvozdev VA, Klenov MS. Interplay of transposon-silencing genes in the germline of Drosophila melanogaster. Mol Biol 2011. [DOI: 10.1134/s0026893311030174] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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31
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Anne J. Targeting and anchoring Tudor in the pole plasm of the Drosophila oocyte. PLoS One 2010; 5:e14362. [PMID: 21179512 PMCID: PMC3002268 DOI: 10.1371/journal.pone.0014362] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2010] [Accepted: 11/16/2010] [Indexed: 11/19/2022] Open
Abstract
Background Germline formation is a highly regulated process in all organisms. In Drosophila embryos germ cells are specified by the pole plasm, a specialized cytoplasmic region containing polar granules. Components of these granules are also present in the perinuclear ring surrounding nurse cells, the nuage. Two such molecules are the Vasa and Tudor proteins. How Tudor localizes and is maintained in the pole plasm is, however, not known. Methodology/Principal Findings Here, the process of Tudor localization in nuage and pole plasm was analyzed. The initial positioning of Tudor at the posterior pole of stage 9 oocytes was found to occur in the absence of a structurally detectable nuage. However, in mutants for genes encoding components of the nuage, including vasa, aubergine, maelstrom, and krimper, Tudor was detached from the posterior cortex in stage 10 oocytes, suggesting a prior passage in the nuage for its stability in the pole plasm. Further studies indicated that Valois, which was previously shown to bind in vitro to Tudor, mediates the localization of Tudor in the pole plasm by physically interacting with Oskar, the polar granule organizer. An association between Tudor and Vasa mediated by RNA was also detected in ovarian extracts. Conclusions/Significance The present data challenge the view that the assembly of the polar granules occurs in a stepwise and hierarchical manner and, consequently, a revised model of polar granule assembly is proposed. In this model Oskar recruits two downstream components of the polar granules, Vasa and Tudor, independently from each other: Vasa directly interacts with Oskar while Valois mediates the recruitment of Tudor by interacting with Oskar and Tudor.
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Affiliation(s)
- Joël Anne
- Department of Developmental Genetics, Deutsches Krebsforschungszentrum, Heidelberg, Germany.
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32
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Nagao A, Mituyama T, Huang H, Chen D, Siomi MC, Siomi H. Biogenesis pathways of piRNAs loaded onto AGO3 in the Drosophila testis. RNA (NEW YORK, N.Y.) 2010; 16:2503-15. [PMID: 20980675 PMCID: PMC2995411 DOI: 10.1261/rna.2270710] [Citation(s) in RCA: 95] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2010] [Accepted: 09/16/2010] [Indexed: 05/25/2023]
Abstract
PIWI-interacting RNAs (piRNAs) silence transposable elements in animal germ cells. In Drosophila ovaries, piRNAs are produced by two distinct pathways: the "ping-pong" amplification cycle that operates in germ cells and a ping-pong-independent pathway termed the primary pathway that mainly operates in somatic cells. AGO3, one of three PIWI proteins in flies, is involved in the ping-pong cycle in ovaries. We characterized AGO3-associated piRNAs in fly testes and found that like in ovaries, AGO3 functions in the ping-pong cycle with Aubergine (Aub) for piRNA production from transposon transcripts. In contrast, most AGO3-associated piRNAs corresponding to Suppressor of Stellate [Su(Ste)] genes are antisense-oriented and bound to Aub. In addition, the vast majority of AGO3-bound piRNAs derived from the AT-chX locus on chromosome X are antisense-oriented and are also found among Aub-associated piRNAs. The presence of very few sense Su(Ste) and AT-chX piRNAs suggests that biogenesis of both Su(Ste) and AT-chX piRNAs by a ping-pong mechanism only is highly unlikely. Nevertheless, the mutual interdependence of AGO3 and Aub for the accumulation of these piRNAs shows that their production relies on both AGO3 and Aub. Analysis of piRNA pathway mutants revealed that although the requirements for piRNA factors for Su(Ste)- and AT-chX-piRNA levels mostly overlap and resemble those for the ping-pong mechanism in the ovaries, Armitage (armi) is not required for the accumulation of AT-chX-1 piRNA. These findings suggest that the impacts of armi mutants on the operation of the piRNA pathway are variable in germ cells of fly testes.
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Affiliation(s)
- Akihiro Nagao
- Department of Molecular Biology, Keio University School of Medicine, Tokyo 160-8582, Japan
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33
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Orsi GA, Joyce EF, Couble P, McKim KS, Loppin B. Drosophila I-R hybrid dysgenesis is associated with catastrophic meiosis and abnormal zygote formation. J Cell Sci 2010; 123:3515-24. [PMID: 20841382 DOI: 10.1242/jcs.073890] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
The Drosophila I-R type of hybrid dysgenesis is a sterility syndrome (SF sterility) associated with the mobilization of the I retrotransposon in female germ cells. SF sterility results from a maternal-effect embryonic lethality whose origin has remained unclear since its discovery about 40 years ago. Here, we show that meiotic divisions in SF oocytes are catastrophic and systematically fail to produce a functional female pronucleus at fertilization. As a consequence, most embryos from SF females rapidly arrest their development with aneuploid or damaged nuclei, whereas others develop as non-viable, androgenetic haploid embryos. Finally, we show that, in contrast to mutants affecting the biogenesis of piRNAs, SF egg chambers do not accumulate persistent DNA double-strand breaks, suggesting that I-element activity might perturb the functional organization of meiotic chromosomes without triggering an early DNA damage response.
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Affiliation(s)
- Guillermo A Orsi
- Centre de Génétique Moléculaire et Cellulaire, CNRS UMR5534, University of Lyon, UCBL Lyon1, Villeurbanne, F-69100, France
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34
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Olivieri D, Sykora MM, Sachidanandam R, Mechtler K, Brennecke J. An in vivo RNAi assay identifies major genetic and cellular requirements for primary piRNA biogenesis in Drosophila. EMBO J 2010; 29:3301-17. [PMID: 20818334 DOI: 10.1038/emboj.2010.212] [Citation(s) in RCA: 204] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2010] [Accepted: 08/10/2010] [Indexed: 11/09/2022] Open
Abstract
In Drosophila, PIWI proteins and bound PIWI-interacting RNAs (piRNAs) form the core of a small RNA-mediated defense system against selfish genetic elements. Within germline cells, piRNAs are processed from piRNA clusters and transposons to be loaded into Piwi/Aubergine/AGO3 and a subset of piRNAs undergoes target-dependent amplification. In contrast, gonadal somatic support cells express only Piwi, lack signs of piRNA amplification and exhibit primary piRNA biogenesis from piRNA clusters. Neither piRNA processing/loading nor Piwi-mediated target silencing is understood at the genetic, cellular or molecular level. We developed an in vivo RNAi assay for the somatic piRNA pathway and identified the RNA helicase Armitage, the Tudor domain containing RNA helicase Yb and the putative nuclease Zucchini as essential factors for primary piRNA biogenesis. Lack of any of these proteins leads to transposon de-silencing, to a collapse in piRNA levels and to a failure in Piwi-nuclear accumulation. We show that Armitage and Yb interact physically and co-localize in cytoplasmic Yb bodies, which flank P bodies. Loss of Zucchini leads to an accumulation of Piwi and Armitage in Yb bodies, indicating that Yb bodies are sites of primary piRNA biogenesis.
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Affiliation(s)
- Daniel Olivieri
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), Vienna, Austria
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35
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Lau NC. Small RNAs in the animal gonad: guarding genomes and guiding development. Int J Biochem Cell Biol 2010; 42:1334-47. [PMID: 20227517 DOI: 10.1016/j.biocel.2010.03.005] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2009] [Accepted: 03/08/2010] [Indexed: 10/19/2022]
Abstract
Germ cells must safeguard, apportion, package, and deliver their genomes with exquisite precision to ensure proper reproduction and embryonic development. Classical genetic approaches have identified many genes controlling animal germ cell development, but only recently have some of these genes been linked to the RNA interference (RNAi) pathway, a gene silencing mechanism centered on small regulatory RNAs. Germ cells contain microRNAs (miRNAs), endogenous siRNAs (endo-siRNAs), and Piwi-interacting RNAs (piRNAs); these are bound by members of the Piwi/Argonaute protein family. piwi genes were known to specify germ cell development, but we now understand that mutations disrupting germline development can also affect small RNA accumulation. Small RNA studies in germ cells have revealed a surprising diversity of regulatory mechanisms and a unifying function for germline genes in controlling the spread of transposable elements. Future challenges will be to understand the production of germline small RNAs and to identify the full breadth of gene regulation by these RNAs. Progress in this area will likely impact biomedical goals of manipulating stem cells and preventing diseases caused by the transposition of mobile DNA elements.
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Affiliation(s)
- Nelson C Lau
- Department of Biology, Brandeis University, 415 South Street, Waltham, MA 02454, USA.
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36
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Bazooka regulates microtubule organization and spatial restriction of germ plasm assembly in the Drosophila oocyte. Dev Biol 2010; 340:528-38. [PMID: 20152826 DOI: 10.1016/j.ydbio.2010.02.006] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2009] [Revised: 01/30/2010] [Accepted: 02/02/2010] [Indexed: 11/20/2022]
Abstract
Localization of the germ plasm to the posterior of the Drosophila oocyte is required for anteroposterior patterning and germ cell development during embryogenesis. While mechanisms governing the localization of individual germ plasm components have been elucidated, the process by which germ plasm assembly is restricted to the posterior pole is poorly understood. In this study, we identify a novel allele of bazooka (baz), the Drosophila homolog of Par-3, which has allowed the analysis of baz function throughout oogenesis. We demonstrate that baz is required for spatial restriction of the germ plasm and axis patterning, and we uncover multiple requirements for baz in regulating the organization of the oocyte microtubule cytoskeleton. Our results suggest that distinct cortical domains established by Par proteins polarize the oocyte through differential effects on microtubule organization. We further show that microtubule plus-end enrichment is sufficient to drive germ plasm assembly even at a distance from the oocyte cortex, suggesting that control of microtubule organization is critical not only for the localization of germ plasm components to the posterior of the oocyte but also for the restriction of germ plasm assembly to the posterior pole.
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37
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Chuma S, Pillai RS. Retrotransposon silencing by piRNAs: ping-pong players mark their sub-cellular boundaries. PLoS Genet 2009; 5:e1000770. [PMID: 20011121 PMCID: PMC2782134 DOI: 10.1371/journal.pgen.1000770] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Affiliation(s)
- Shinichiro Chuma
- Institute for Frontier Medical Sciences, Kyoto University, Kyoto, Japan.
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Xiao L, Wang Y, Zhou Y, Sun Y, Sun W, Wang L, Zhou C, Zhou J, Zhang J. Identification of a novel human cancer/testis gene MAEL that is regulated by DNA methylation. Mol Biol Rep 2009; 37:2355-60. [DOI: 10.1007/s11033-009-9741-x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2009] [Accepted: 08/05/2009] [Indexed: 01/10/2023]
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39
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Zhang D, Xiong H, Shan J, Xia X, Trudeau VL. Functional insight into Maelstrom in the germline piRNA pathway: a unique domain homologous to the DnaQ-H 3'-5' exonuclease, its lineage-specific expansion/loss and evolutionarily active site switch. Biol Direct 2008; 3:48. [PMID: 19032786 PMCID: PMC2628886 DOI: 10.1186/1745-6150-3-48] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2008] [Accepted: 11/25/2008] [Indexed: 11/10/2022] Open
Abstract
Abstract Maelstrom (MAEL) plays a crucial role in a recently-discovered piRNA pathway; however its specific function remains unknown. Here a novel MAEL-specific domain characterized by a set of conserved residues (Glu-His-His-Cys-His-Cys, EHHCHC) was identified in a broad range of species including vertebrates, sea squirts, insects, nematodes, and protists. It exhibits ancient lineage-specific expansions in several species, however, appears to be lost in all examined teleost fish species. Functional involvement of MAEL domains in DNA- and RNA-related processes was further revealed by its association with HMG, SR-25-like and HDAC_interact domains. A distant similarity to the DnaQ-H 3'–5' exonuclease family with the RNase H fold was discovered based on the evidence that all MAEL domains adopt the canonical RNase H fold; and several protist MAEL domains contain the conserved 3'–5' exonuclease active site residues (Asp-Glu-Asp-His-Asp, DEDHD). This evolutionary link together with structural examinations leads to a hypothesis that MAEL domains may have a potential nuclease activity or RNA-binding ability that may be implicated in piRNA biogenesis. The observed transition of two sets of characteristic residues between the ancestral DnaQ-H and the descendent MAEL domains may suggest a new mode for protein function evolution called "active site switch", in which the protist MAEL homologues are the likely evolutionary intermediates due to harboring the specific characteristics of both 3'–5' exonuclease and MAEL domains. Reviewers This article was reviewed by L Aravind, Wing-Cheong Wong and Frank Eisenhaber. For the full reviews, please go to the Reviewers' Comments section.
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Affiliation(s)
- Dapeng Zhang
- Department of Biology, Centre for Advanced Research in Environmental Genomics, University of Ottawa, Ottawa, Ontario, Canada.
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40
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Abstract
In this issue of Developmental Cell, Soper et al. (2008) report that the mammalian MAELSTROM (MAEL) protein is critical for transposon silencing in the male germline. Loss of MAEL is associated with meiotic failure and DNA damage, suggesting that efficient transposable element restraining mechanisms must be in place for the preservation of germline integrity.
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41
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Soper SF, van der Heijden GW, Hardiman TC, Goodheart M, Martin SL, de Boer P, Bortvin A. Mouse maelstrom, a component of nuage, is essential for spermatogenesis and transposon repression in meiosis. Dev Cell 2008; 15:285-97. [PMID: 18694567 PMCID: PMC2546488 DOI: 10.1016/j.devcel.2008.05.015] [Citation(s) in RCA: 257] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2008] [Revised: 05/19/2008] [Accepted: 05/30/2008] [Indexed: 11/20/2022]
Abstract
Tight control of transposon activity is essential for the integrity of the germline. Recently, a germ-cell-specific organelle, nuage, was proposed to play a role in transposon repression. To test this hypothesis, we disrupted a murine homolog of a Drosophila nuage protein Maelstrom. Effects on male meiotic chromosome synapsis and derepression of transposable elements (TEs) were observed. In the adult Mael(-/-) testes, LINE-1 (L1) derepression occurred at the onset of meiosis. As a result, Mael(-/-) spermatocytes were flooded with L1 ribonucleoproteins (RNPs) that accumulated in large cytoplasmic enclaves and nuclei. Mael(-/-) spermatocytes with nuclear L1 RNPs exhibited massive DNA damage and severe chromosome asynapsis even in the absence of SPO11-generated meiotic double-strand breaks. This study demonstrates that MAEL, a nuage component, is indispensable for the silencing of TEs and identifies the initiation of meiosis as an important step in TE control in the male germline.
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Affiliation(s)
- Sarah F.C. Soper
- Biology Department, Johns Hopkins University, Baltimore, MD 21218, USA
| | | | - Tara C. Hardiman
- Department of Embryology, Carnegie Institution of Washington, Baltimore, MD 21218, USA
| | - Mary Goodheart
- Howard Hughes Medical Institute, Whitehead Institute, and Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02142, USA
| | - Sandra L. Martin
- Department of Cell and Developmental Biology and Molecular Biology Program, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Peter de Boer
- Department of Obstetrics and Gynaecology, Radboud University Nijmegen Medical Centre, 6500 HB Nijmegen, The Netherlands
| | - Alex Bortvin
- Department of Embryology, Carnegie Institution of Washington, Baltimore, MD 21218, USA
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42
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A cellular basis for Wolbachia recruitment to the host germline. PLoS Pathog 2008; 3:e190. [PMID: 18085821 PMCID: PMC2134955 DOI: 10.1371/journal.ppat.0030190] [Citation(s) in RCA: 99] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2007] [Accepted: 10/26/2007] [Indexed: 11/19/2022] Open
Abstract
Wolbachia are among the most widespread intracellular bacteria, carried by thousands of metazoan species. The success of Wolbachia is due to efficient vertical transmission by the host maternal germline. Some Wolbachia strains concentrate at the posterior of host oocytes, which promotes Wolbachia incorporation into posterior germ cells during embryogenesis. The molecular basis for this localization strategy is unknown. Here we report that the wMel Wolbachia strain relies upon a two-step mechanism for its posterior localization in oogenesis. The microtubule motor protein kinesin-1 transports wMel toward the oocyte posterior, then pole plasm mediates wMel anchorage to the posterior cortex. Trans-infection tests demonstrate that factors intrinsic to Wolbachia are responsible for directing posterior Wolbachia localization in oogenesis. These findings indicate that Wolbachia can direct the cellular machinery of host oocytes to promote germline-based bacterial transmission. This study also suggests parallels between Wolbachia localization mechanisms and those used by other intracellular pathogens.
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43
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Abstract
The body axes of the fruit fly are established in mid-oogenesis by the localization of three mRNA determinants, bicoid, oskar, and gurken, within the oocyte. General mechanisms of RNA localization and cell polarization, applicable to many cell types, have emerged from investigation of these determinants in Drosophila oogenesis. Localization of these RNAs is dependent on the germline microtubules, which reorganize to form a polarized array at mid-oogenesis in response to a signaling relay between the oocyte and the surrounding somatic follicle cells. Here we describe what is known about this microtubule reorganization and the signaling relay that triggers it. Recent studies have identified a number of ubiquitous RNA binding proteins essential for this process. So far, no targets for any of these proteins have been identified, and future work will be needed to illuminate how they function to reorganize microtubes and whether similar mechanisms also exist in other cell types.
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Affiliation(s)
- Josefa Steinhauer
- Skirball Institute for Biomolecular Medicine and Department of Developmental Genetics, New York University School of Medicine, New York, New York 10016,USA.
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44
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Gallardo TD, John GB, Shirley L, Contreras CM, Akbay EA, Haynie JM, Ward SE, Shidler MJ, Castrillon DH. Genomewide discovery and classification of candidate ovarian fertility genes in the mouse. Genetics 2007; 177:179-94. [PMID: 17660561 PMCID: PMC2013718 DOI: 10.1534/genetics.107.074823] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2007] [Accepted: 07/13/2007] [Indexed: 11/18/2022] Open
Abstract
Female infertility syndromes are among the most prevalent chronic health disorders in women, but their genetic basis remains unknown because of uncertainty regarding the number and identity of ovarian factors controlling the assembly, preservation, and maturation of ovarian follicles. To systematically discover ovarian fertility genes en masse, we employed a mouse model (Foxo3) in which follicles are assembled normally but then undergo synchronous activation. We developed a microarray-based approach for the systematic discovery of tissue-specific genes and, by applying it to Foxo3 ovaries and other samples, defined a surprisingly large set of ovarian factors (n = 348, approximately 1% of the mouse genome). This set included the vast majority of known ovarian factors, 44% of which when mutated produce female sterility phenotypes, but most were novel. Comparative profiling of other tissues, including microdissected oocytes and somatic cells, revealed distinct gene classes and provided new insights into oogenesis and ovarian function, demonstrating the utility of our approach for tissue-specific gene discovery. This study will thus facilitate comprehensive analyses of follicle development, ovarian function, and female infertility.
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Affiliation(s)
- Teresa D Gallardo
- Department of Pathology and Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical Center, Dallas, Texas 75390-9072, USA
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45
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Lim AK, Kai T. Unique germ-line organelle, nuage, functions to repress selfish genetic elements in Drosophila melanogaster. Proc Natl Acad Sci U S A 2007; 104:6714-9. [PMID: 17428915 PMCID: PMC1871851 DOI: 10.1073/pnas.0701920104] [Citation(s) in RCA: 272] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2007] [Indexed: 01/25/2023] Open
Abstract
The nuage is an electron-dense perinuclear structure that is known to be a hallmark of animal germ-line cells. Although the conservation of the nuage throughout evolution accentuates its essentiality, its role(s) and the exact mechanism(s) by which it functions in the germ line still remain unknown. Here, we report a nuage component, Krimper (KRIMP), in Drosophila melanogaster and show that it ensures the repression of the selfish genetic elements in the female germ line. The Krimp loss-of-function allele exhibited female sterility, defects in karyosome formation and oocyte polarity, and precocious osk translation. These phenotypes are commonly observed in the other nuage component mutants, vasa (vas) and maelstrom (mael), and the RNA-silencing component mutants, spindle-E (spn-E) and aubergine (aub), suggesting a shared underlying defect that uses RNA silencing. Moreover, we demonstrated that the localization of the nuage components depends on both SPN-E and AUB and that the selfish genetic elements were derepressed to different extents in the nuage component mutants, as well as in aub and armitage (armi) mutants. In the nuage component mutants, vas, krimp, and mael, the levels of roo, I-element, and HeT-A repeat-associated small interfering RNAs were greatly reduced. Hence, our data suggest that the nuage functions as a specialized center that protects the genome in the germ-line cells via gene regulation mediated by repeat-associated small interfering RNAs.
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Affiliation(s)
- Ai Khim Lim
- Germ-Line Biology Laboratory, Temasek Life Sciences Laboratory and Department of Biological Sciences, National University of Singapore, 1 Research Link, Singapore 117604
| | - Toshie Kai
- Germ-Line Biology Laboratory, Temasek Life Sciences Laboratory and Department of Biological Sciences, National University of Singapore, 1 Research Link, Singapore 117604
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46
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Megosh HB, Cox DN, Campbell C, Lin H. The role of PIWI and the miRNA machinery in Drosophila germline determination. Curr Biol 2006; 16:1884-94. [PMID: 16949822 DOI: 10.1016/j.cub.2006.08.051] [Citation(s) in RCA: 174] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2006] [Revised: 07/27/2006] [Accepted: 08/17/2006] [Indexed: 10/24/2022]
Abstract
BACKGROUND The germ plasm has long been demonstrated to be necessary and sufficient for germline determination, with translational regulation playing a key role in the process. Beyond this, little is known about molecular activities underlying germline determination. RESULTS We report the function of Drosophila PIWI, DICER-1, and dFMRP (Fragile X Mental Retardation Protein) in germline determination. PIWI is a maternal component of the polar granule, a germ-plasm-specific organelle essential for germline specification. Depleting maternal PIWI does not affect OSK or VASA expression or abdominal patterning but leads to failure in pole-plasm maintenance and primordial-germ-cell (PGC) formation, whereas doubling and tripling the maternal piwi dose increases OSK and VASA levels correspondingly and doubles and triples the number of PGCs, respectively. Moreover, PIWI forms a complex with dFMRP and DICER-1, but not with DICER-2, in polar-granule-enriched fractions. Depleting DICER-1, but not DICER-2, also leads to a severe pole-plasm defect and a reduced PGC number. These effects are also seen, albeit to a lesser extent, for dFMRP, another component of the miRISC complex. CONCLUSIONS Because DICER-1 is required for the miRNA pathway and DICER-2 is required for the siRNA pathway yet neither is required for the rasiRNA pathway, our data implicate a crucial role of the PIWI-mediated miRNA pathway in regulating the levels of OSK, VASA, and possibly other genes involved in germline determination in Drosophila.
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Affiliation(s)
- Heather B Megosh
- Department of Cell Biology and Duke University Medical Center, Durham, North Carolina 27705, USA
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47
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Claussen M, Suter B. BicD-dependent localization processes: from Drosophilia development to human cell biology. Ann Anat 2006; 187:539-53. [PMID: 16320833 DOI: 10.1016/j.aanat.2005.07.004] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Many eukaryotic cells depend on proper cell polarization for their development and physiological function. The establishment of these polarities often involve the subcellular localization of a specific subset of proteins, RNAs and organelles. In Drosophila, the microtubule-dependent BicD (BicaudalD) localization machinery is involved in the proper localization of mRNA during oogenesis and embryogenesis and the proper positioning of the oocyte and photoreceptor nuclei. BicD acts together with the minus-end directed motor dynein as well as Egl and Lis-1. The finding that the mammalian homologs of BicD function in retrograde Golgi-to-ER transport has supported the view that BicD may be part of a repeatedly used and evolutionary conserved localization machinery. In this review we focus on the various processes in which BicD is involved during Drosophilian development and in mammals. In addition, we evaluate the interactions between BicD, the dynein localization machinery and associated factors.
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Affiliation(s)
- Maike Claussen
- Institute of Cell Biology, University of Berne, Baltzerstrasse 4, 3012 Bern, Switzerland
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48
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Ferree PM, Frydman HM, Li JM, Cao J, Wieschaus E, Sullivan W. Wolbachia utilizes host microtubules and Dynein for anterior localization in the Drosophila oocyte. PLoS Pathog 2005; 1:e14. [PMID: 16228015 PMCID: PMC1253842 DOI: 10.1371/journal.ppat.0010014] [Citation(s) in RCA: 138] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2005] [Accepted: 08/31/2005] [Indexed: 11/24/2022] Open
Abstract
To investigate the role of the host cytoskeleton in the maternal transmission of the endoparasitic bacteria Wolbachia, we have characterized their distribution in the female germ line of Drosophila melanogaster. In the germarium, Wolbachia are distributed to all germ cells of the cyst, establishing an early infection in the cell destined to become the oocyte. During mid-oogenesis, Wolbachia exhibit a distinct concentration between the anterior cortex and the nucleus in the oocyte, where many bacteria appear to contact the nuclear envelope. Following programmed rearrangement of the microtubule network, Wolbachia dissociate from this anterior position and become dispersed throughout the oocyte. This localization pattern is distinct from mitochondria and all known axis determinants. Manipulation of microtubules and cytoplasmic Dynein and Dynactin, but not Kinesin-1, disrupts anterior bacterial localization in the oocyte. In live egg chambers, Wolbachia exhibit movement in nurse cells but not in the oocyte, suggesting that the bacteria are anchored by host factors. In addition, we identify mid-oogenesis as a period in the life cycle of Wolbachia in which bacterial replication occurs. Total bacterial counts show that Wolbachia increase at a significantly higher rate in the oocyte than in the average nurse cell, and that normal Wolbachia levels in the oocyte depend on microtubules. These findings demonstrate that Wolbachia utilize the host microtubule network and associated proteins for their subcellular localization in the Drosophila oocyte. These interactions may also play a role in bacterial motility and replication, ultimately leading to the bacteria's efficient maternal transmission. Intracellular bacteria that cause disease exploit host cells for their survival and reproduction. Here the authors are studying Wolbachia, an intracellular bacteria that infects many insect species and other invertebrates, such as filarial nematodes, the agents of diseases such as African river blindness and elephantiasis. Wolbachia transmission is similar to mitochondrial inheritance, that is, from mother to offspring in the host. However, little is known about the mechanisms of this maternal transmission and the interactions of Wolbachia and its hosts at the cellular level. Here the authors show that in the fruit fly Drosophila melanogaster, Wolbachia bacteria are initially distributed uniformly throughout the female germ line but concentrate during the middle stages of oogenesis in the future oocyte, exhibiting a striking anterior localization that is distinct from mitochondria and all known axis determinants. The authors demonstrate that microtubules and the minus-end-directed motor Dynein are required for this subcellular localization, suggesting that Wolbachia uses the host's microtubule cytoskeleton and transport system to ensure its transmission to the next generation. This microtubule dependence contrasts with the Actin-based motility observed for many other intracellular bacteria and may provide a foundation for further probing of the molecular and cellular basis of Wolbachia replication and transmission.
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Affiliation(s)
- Patrick M Ferree
- Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Cruz, California, United States of America
| | - Horacio M Frydman
- Howard Hughes Medical Institute, Department of Molecular Biology, Princeton University, Princeton, New Jersey, United States of America
| | - Jennifer M Li
- Howard Hughes Medical Institute, Department of Molecular Biology, Princeton University, Princeton, New Jersey, United States of America
| | - Jian Cao
- Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Cruz, California, United States of America
| | - Eric Wieschaus
- Howard Hughes Medical Institute, Department of Molecular Biology, Princeton University, Princeton, New Jersey, United States of America
| | - William Sullivan
- Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Cruz, California, United States of America
- * To whom correspondence should be addressed. E-mail:
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49
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Gortchakov AA, Eggert H, Gan M, Mattow J, Zhimulev IF, Saumweber H. Chriz, a chromodomain protein specific for the interbands of Drosophila melanogaster polytene chromosomes. Chromosoma 2005; 114:54-66. [PMID: 15821938 DOI: 10.1007/s00412-005-0339-3] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2004] [Revised: 03/15/2005] [Accepted: 03/16/2005] [Indexed: 01/04/2023]
Abstract
Polytene interphase chromosomes are compacted into a series of bands and interbands reflecting their organization into independent chromosomal domains. In order to understand chromosomal organization, we set out to study the role of proteins that are selective for interbands. Here we describe the Drosophila melanogaster chromodomain protein Chriz that is coimmunoprecipitated with the zinc finger protein Z4. Both proteins colocalize exclusively to the interbands on Drosophila polytene chromosomes. Like Z4, Chriz is ubiquitously expressed throughout development and is associated with chromatin in all interphase nuclei. Following dissociation from chromatin, early in mitosis Chriz binds to the centrosomes and to the mitotic spindle. Newly induced amorphic Chriz alleles are early lethal, and ubiquitous overexpression of Chriz is lethal as well. Available Chriz hypomorphs which survive until pupal stage have a normal chromosomal phenotype. Reducing Z4 protein does not affect Chriz binding to polytene chromosomes and vice versa. Z4 is still chromosomally bound when Chriz protein is depleted by RNA interference.
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Affiliation(s)
- A A Gortchakov
- Institute of Cytology and Genetics, Siberian Branch of Russian Academy of Sciences, Novosibirsk, Russia
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50
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Huynh JR, St Johnston D. The origin of asymmetry: early polarisation of the Drosophila germline cyst and oocyte. Curr Biol 2004; 14:R438-49. [PMID: 15182695 DOI: 10.1016/j.cub.2004.05.040] [Citation(s) in RCA: 197] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The anterior-posterior axis of Drosophila is established before fertilisation when the oocyte becomes polarised to direct the localisation of bicoid and oskar mRNAs to opposite poles of the egg. Here we review recent results that reveal that the oocyte acquires polarity much earlier than previously thought, at the time when it acquires its fate. The oocyte arises from a 16-cell germline cyst, and its selection and the initial cue for its polarisation are controlled by the asymmetric segregation of a germline specific organelle called the fusome. Several different downstream pathways then interpret this asymmetry to restrict distinct aspects of oocyte identity to this cell. Mutations in any of the six conserved Par proteins disrupt the early polarisation of the oocyte and lead to a failure to maintain its identity. Surprisingly, mutations affecting the control of the mitotic or meiotic cell cycle also lead to a failure to maintain the oocyte fate, indicating crosstalk between the nuclear and cytoplasmic events of oocyte differentiation. The early polarity of the oocyte initiates a series of reciprocal signaling events between the oocyte and the somatic follicle cells that leads to a reversal of oocyte polarity later in oogenesis, which defines the anterior-posterior axis of the embryo.
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Affiliation(s)
- Jean-René Huynh
- Institut Jacques-Monod, CNRS, Universités Paris 6 et 7: 2: Place Jussieu, F-75251 Paris, Cedex 05: France
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