1
|
Buglak DB, Holmes KHM, Galletta BJ, Rusan NM. The Proximal Centriole-Like Structure Anchors the Centriole to the Sperm Nucleus. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.15.589606. [PMID: 38712096 PMCID: PMC11071290 DOI: 10.1101/2024.04.15.589606] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2024]
Abstract
Proper connection between the sperm head and tail is critical for sperm motility and fertilization. The link between the head and tail is mediated by the Head-Tail Coupling Apparatus (HTCA), which secures the axoneme (tail) to the nucleus (head). However, the molecular architecture of the HTCA is not well understood. Here, we use Drosophila to create a high-resolution map of proteins and structures at the HTCA throughout spermiogenesis. Using structured illumination microscopy, we demonstrate that key HTCA proteins Spag4 and Yuri form a 'Centriole Cap' that surrounds the centriole (or Basal Body) as it is inserted, or embedded into the surface of the nucleus. As development progresses, the centriole is laterally displaces to the side of the nucleus, during which time the HTCA expands under the nucleus, forming what we term the 'Nuclear Shelf.' We next show that the proximal centriole-like (PCL) structure is positioned under the Nuclear Shelf and functions as a critical stabilizer of the centriole-nuclear attachment. Together, our data indicate that the HTCA is complex, multi-point attachment site that simultaneously engages the PCL, the centriole, and the nucleus to ensure proper head-tail connection during late-stage spermiogenesis.
Collapse
|
2
|
Vedelek V, Jankovics F, Zádori J, Sinka R. Mitochondrial Differentiation during Spermatogenesis: Lessons from Drosophila melanogaster. Int J Mol Sci 2024; 25:3980. [PMID: 38612789 PMCID: PMC11012351 DOI: 10.3390/ijms25073980] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2024] [Revised: 03/22/2024] [Accepted: 03/28/2024] [Indexed: 04/14/2024] Open
Abstract
Numerous diseases can arise as a consequence of mitochondrial malfunction. Hence, there is a significant focus on studying the role of mitochondria in cancer, ageing, neurodegenerative diseases, and the field of developmental biology. Mitochondria could exist as discrete organelles in the cell; however, they have the ability to fuse, resulting in the formation of interconnected reticular structures. The dynamic changes between these forms correlate with mitochondrial function and mitochondrial health, and consequently, there is a significant scientific interest in uncovering the specific molecular constituents that govern these transitions. Moreover, the specialized mitochondria display a wide array of variable morphologies in their cristae formations. These inner mitochondrial structures are closely associated with the specific functions performed by the mitochondria. In multiple cases, the presence of mitochondrial dysfunction has been linked to male sterility, as it has been observed to cause a range of abnormal spermatogenesis and sperm phenotypes in different species. This review aims to elucidate the dynamic alterations and functions of mitochondria in germ cell development during the spermatogenesis of Drosophila melanogaster.
Collapse
Affiliation(s)
- Viktor Vedelek
- Department of Genetics, Faculty of Science and Informatics, University of Szeged, 6726 Szeged, Hungary
| | - Ferenc Jankovics
- Institute of Genetics, HUN-REN Biological Research Centre, 6726 Szeged, Hungary;
- Department of Medical Biology, Albert Szent-Györgyi Medical Centre, University of Szeged, 6720 Szeged, Hungary
| | - János Zádori
- Institute of Reproductive Medicine, Albert Szent-Györgyi Medical Centre, University of Szeged, 6723 Szeged, Hungary;
| | - Rita Sinka
- Department of Genetics, Faculty of Science and Informatics, University of Szeged, 6726 Szeged, Hungary
| |
Collapse
|
3
|
Hannaford MR, Rusan NM. Positioning centrioles and centrosomes. J Cell Biol 2024; 223:e202311140. [PMID: 38512059 PMCID: PMC10959756 DOI: 10.1083/jcb.202311140] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2023] [Revised: 02/23/2024] [Accepted: 02/26/2024] [Indexed: 03/22/2024] Open
Abstract
Centrosomes are the primary microtubule organizer in eukaryotic cells. In addition to shaping the intracellular microtubule network and the mitotic spindle, centrosomes are responsible for positioning cilia and flagella. To fulfill these diverse functions, centrosomes must be properly located within cells, which requires that they undergo intracellular transport. Importantly, centrosome mispositioning has been linked to ciliopathies, cancer, and infertility. The mechanisms by which centrosomes migrate are diverse and context dependent. In many cells, centrosomes move via indirect motor transport, whereby centrosomal microtubules engage anchored motor proteins that exert forces on those microtubules, resulting in centrosome movement. However, in some cases, centrosomes move via direct motor transport, whereby the centrosome or centriole functions as cargo that directly binds molecular motors which then walk on stationary microtubules. In this review, we summarize the mechanisms of centrosome motility and the consequences of centrosome mispositioning and identify key questions that remain to be addressed.
Collapse
Affiliation(s)
- Matthew R. Hannaford
- Cell and Developmental Biology Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, USA
| | - Nasser M. Rusan
- Cell and Developmental Biology Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, USA
| |
Collapse
|
4
|
Liu XP, Liu CY, Feng YJ, Guo XK, Zhang LS, Wang MQ, Li YY, Zeng FR, Nolan T, Mao JJ. Male vitellogenin regulates gametogenesis through a testis-enriched big protein in Chrysopa pallens. INSECT MOLECULAR BIOLOGY 2024; 33:17-28. [PMID: 37707297 DOI: 10.1111/imb.12873] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Accepted: 08/30/2023] [Indexed: 09/15/2023]
Abstract
In insects, vitellogenin (Vg) is generally viewed as a female-specific protein. Its primary function is to supply nutrition to developing embryos. Here, we reported Vg from the male adults of a natural predator, Chrysopa pallens. The male Vg was depleted by RNAi. Mating with Vg-deficient male downregulated female Vg expression, suppressed ovarian development and decreased reproductive output. Whole-organism transcriptome analysis after male Vg knockdown showed no differential expression of the known spermatogenesis-related regulators and seminal fluid protein genes, but a sharp downregulation of an unknown gene, which encodes a testis-enriched big protein (Vcsoo). Separate knockdown of male Vg and Vcsoo disturbed the assembly of spermatid cytoplasmic organelles in males and suppressed the expansion of ovary germarium in mated females. These results demonstrated that C. pallens male Vg signals through the downstream Vcsoo and regulates male and female reproduction.
Collapse
Affiliation(s)
- Xiao-Ping Liu
- Key Laboratory of Natural Enemy Insects, Ministry of Agriculture and Rural Affairs, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, People's Republic of China
| | - Chang-Yan Liu
- Institute of Food Crops, Hubei Academy of Agricultural Sciences/Hubei Key Laboratory of Food Crop Germplasm and Genetic, Wuhan, People's Republic of China
| | - Yan-Jiao Feng
- Key Laboratory of Natural Enemy Insects, Ministry of Agriculture and Rural Affairs, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, People's Republic of China
| | - Xing-Kai Guo
- Key Laboratory of Natural Enemy Insects, Ministry of Agriculture and Rural Affairs, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, People's Republic of China
| | - Li-Sheng Zhang
- Key Laboratory of Natural Enemy Insects, Ministry of Agriculture and Rural Affairs, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, People's Republic of China
| | - Meng-Qing Wang
- Key Laboratory of Natural Enemy Insects, Ministry of Agriculture and Rural Affairs, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, People's Republic of China
| | - Yu-Yan Li
- Key Laboratory of Natural Enemy Insects, Ministry of Agriculture and Rural Affairs, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, People's Republic of China
| | - Fan-Rong Zeng
- Key Laboratory of Natural Enemy Insects, Ministry of Agriculture and Rural Affairs, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, People's Republic of China
| | - Tony Nolan
- Liverpool School of Tropical Medicine, Liverpool, UK
| | - Jian-Jun Mao
- Key Laboratory of Natural Enemy Insects, Ministry of Agriculture and Rural Affairs, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, People's Republic of China
| |
Collapse
|
5
|
Ben-Mahmoud A, Kishikawa S, Gupta V, Leach NT, Shen Y, Moldovan O, Goel H, Hopper B, Ranguin K, Gruchy N, Maas SM, Lacassie Y, Kim SH, Kim WY, Quade BJ, Morton CC, Kim CH, Layman LC, Kim HG. A cryptic microdeletion del(12)(p11.21p11.23) within an unbalanced translocation t(7;12)(q21.13;q23.1) implicates new candidate loci for intellectual disability and Kallmann syndrome. Sci Rep 2023; 13:12984. [PMID: 37563198 PMCID: PMC10415337 DOI: 10.1038/s41598-023-40037-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2023] [Accepted: 08/03/2023] [Indexed: 08/12/2023] Open
Abstract
In a patient diagnosed with both Kallmann syndrome (KS) and intellectual disability (ID), who carried an apparently balanced translocation t(7;12)(q22;q24)dn, array comparative genomic hybridization (aCGH) disclosed a cryptic heterozygous 4.7 Mb deletion del(12)(p11.21p11.23), unrelated to the translocation breakpoint. This novel discovery prompted us to consider the possibility that the combination of KS and neurological disorder in this patient could be attributed to gene(s) within this specific deletion at 12p11.21-12p11.23, rather than disrupted or dysregulated genes at the translocation breakpoints. To further support this hypothesis, we expanded our study by screening five candidate genes at both breakpoints of the chromosomal translocation in a cohort of 48 KS patients. However, no mutations were found, thus reinforcing our supposition. In order to delve deeper into the characterization of the 12p11.21-12p11.23 region, we enlisted six additional patients with small copy number variations (CNVs) and analyzed eight individuals carrying small CNVs in this region from the DECIPHER database. Our investigation utilized a combination of complementary approaches. Firstly, we conducted a comprehensive phenotypic-genotypic comparison of reported CNV cases. Additionally, we reviewed knockout animal models that exhibit phenotypic similarities to human conditions. Moreover, we analyzed reported variants in candidate genes and explored their association with corresponding phenotypes. Lastly, we examined the interacting genes associated with these phenotypes to gain further insights. As a result, we identified a dozen candidate genes: TSPAN11 as a potential KS candidate gene, TM7SF3, STK38L, ARNTL2, ERGIC2, TMTC1, DENND5B, and ETFBKMT as candidate genes for the neurodevelopmental disorder, and INTS13, REP15, PPFIBP1, and FAR2 as candidate genes for KS with ID. Notably, the high-level expression pattern of these genes in relevant human tissues further supported their candidacy. Based on our findings, we propose that dosage alterations of these candidate genes may contribute to sexual and/or cognitive impairments observed in patients with KS and/or ID. However, the confirmation of their causal roles necessitates further identification of point mutations in these candidate genes through next-generation sequencing.
Collapse
Affiliation(s)
- Afif Ben-Mahmoud
- Neurological Disorders Research Center, Qatar Biomedical Research Institute, Hamad Bin Khalifa University, Doha, Qatar
| | - Shotaro Kishikawa
- Gene Engineering Division, RIKEN BioResource Research Center, Tsukuba, Japan
| | - Vijay Gupta
- Neurological Disorders Research Center, Qatar Biomedical Research Institute, Hamad Bin Khalifa University, Doha, Qatar
| | - Natalia T Leach
- Integrated Genetics, Laboratory Corporation of America Holdings, 3400 Computer Drive, Westborough, MA, 01581, USA
| | - Yiping Shen
- Division of Genetics and Genomics at Boston Children's Hospital, Harvard Medical School, Boston, MA, 02114, USA
| | - Oana Moldovan
- Medical Genetics Service, Pediatric Department, Hospital Santa Maria, Centro Hospitalar Universitário Lisboa Norte, Lisbon, Portugal
| | - Himanshu Goel
- Hunter Genetics, Waratah, NSW, 2298, Australia
- University of Newcastle, Callaghan, NSW, 2308, Australia
| | - Bruce Hopper
- Forster Genetics-Hunter New England Local Health District, Forster, NSW, 2428, Australia
| | - Kara Ranguin
- Department of Genetics, Reference Center for Rare Diseases of Developmental anomalies and polymalformative syndrome, CHU de Caen Normandie, Caen, France
| | - Nicolas Gruchy
- Department of Genetics, Reference Center for Rare Diseases of Developmental anomalies and polymalformative syndrome, CHU de Caen Normandie, Caen, France
| | - Saskia M Maas
- Department of Human Genetics, Amsterdam University Medical Center, Amsterdam, the Netherlands
- Reproduction and Development Research Institute, University of Amsterdam, Amsterdam, the Netherlands
| | - Yves Lacassie
- Division of Genetics, Department of Pediatrics, Louisiana State University, New Orleans, LA, 70118, USA
| | - Soo-Hyun Kim
- Molecular and Clinical Sciences Research Institute, St. George's, University of London, London, UK
| | - Woo-Yang Kim
- Department of Biological Sciences, Kent State University, Kent, OH, 44242, USA
| | - Bradley J Quade
- Department of Pathology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, 02115, USA
| | - Cynthia C Morton
- Departments of Obstetrics and Gynecology and of Pathology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, 02115, USA
- Broad Institute of MIT and Harvard, Cambridge, MA, 02142, USA
- Manchester Centre for Audiology and Deafness, School of Health Sciences, University of Manchester, Manchester, UK
| | - Cheol-Hee Kim
- Department of Biology, Chungnam National University, Daejeon, 34134, Korea
| | - Lawrence C Layman
- Section of Reproductive Endocrinology, Infertility and Genetics, Department of Obstetrics and Gynecology, Augusta University, Augusta, GA, USA
- Department of Neuroscience and Regenerative Medicine, Augusta University, Augusta, GA, USA
| | - Hyung-Goo Kim
- Neurological Disorders Research Center, Qatar Biomedical Research Institute, Hamad Bin Khalifa University, Doha, Qatar.
- College of Health and Life Sciences, Hamad Bin Khalifa University, Doha, Qatar.
| |
Collapse
|
6
|
Ben-Mahmoud A, Kishikawa S, Gupta V, Leach NT, Shen Y, Moldovan O, Goel H, Hopper B, Ranguin K, Gruchy N, Maas SM, Lacassie Y, Kim SH, Kim WY, Quade BJ, Morton CC, Kim CH, Layman LC, Kim HG. A microdeletion del(12)(p11.21p11.23) with a cryptic unbalanced translocation t(7;12)(q21.13;q23.1) implicates new candidate loci for intellectual disability and Kallmann syndrome. RESEARCH SQUARE 2023:rs.3.rs-2572736. [PMID: 37034680 PMCID: PMC10081357 DOI: 10.21203/rs.3.rs-2572736/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/01/2023]
Abstract
In an apparently balanced translocation t(7;12)(q22;q24)dn exhibiting both Kallmann syndrome (KS) and intellectual disability (ID), we detected a cryptic heterozygous 4.7 Mb del(12)(p11.21p11.23) unrelated to the translocation breakpoint. This new finding raised the possibility that KS combined with neurological disorder in this patient could be caused by gene(s) within this deletion at 12p11.21-12p11.23 instead of disrupted or dysregulated genes at the genomic breakpoints. Screening of five candidate genes at both breakpoints in 48 KS patients we recruited found no mutation, corroborating our supposition. To substantiate this hypothesis further, we recruited six additional subjects with small CNVs and analyzed eight individuals carrying small CNVs in this region from DECIPHER to dissect 12p11.21-12p11.23. We used multiple complementary approaches including a phenotypic-genotypic comparison of reported cases, a review of knockout animal models recapitulating the human phenotypes, and analyses of reported variants in the interacting genes with corresponding phenotypes. The results identified one potential KS candidate gene ( TSPAN11 ), seven candidate genes for the neurodevelopmental disorder ( TM7SF3 , STK38L , ARNTL2 , ERGIC2 , TMTC1 , DENND5B , and ETFBKMT ), and four candidate genes for KS with ID ( INTS13 , REP15 , PPFIBP1 , and FAR2 ). The high-level expression pattern in the relevant human tissues further suggested the candidacy of these genes. We propose that the dosage alterations of the candidate genes may contribute to sexual and/or cognitive impairment in patients with KS and/or ID. Further identification of point mutations through next generation sequencing will be necessary to confirm their causal roles.
Collapse
Affiliation(s)
| | | | | | | | | | - Oana Moldovan
- Hospital Santa Maria, Centro Hospitalar Universitário Lisboa Norte
| | | | - Bruce Hopper
- Forster Genetics-Hunter New England Local Health District
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
7
|
Liu S, Baeg GH, Yang Y, Goh FG, Bao H, Wagner EJ, Yang X, Cai Y. The Integrator complex desensitizes cellular response to TGF-β/BMP signaling. Cell Rep 2023; 42:112007. [PMID: 36641752 DOI: 10.1016/j.celrep.2023.112007] [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: 05/02/2022] [Revised: 10/12/2022] [Accepted: 01/03/2023] [Indexed: 01/15/2023] Open
Abstract
Maintenance of stem cells requires the concerted actions of niche-derived signals and stem cell-intrinsic factors. Although Decapentaplegic (Dpp), a Drosophila bone morphogenetic protein (BMP) molecule, can act as a long-range morphogen, its function is spatially limited to the germline stem cell niche in the germarium. We show here that Integrator, a complex known to be involved in RNA polymerase II (RNAPII)-mediated transcriptional regulation in the nucleus, promotes germline differentiation by restricting niche-derived Dpp/BMP activity in the cytoplasm. Further results show that Integrator works in various developmental contexts to desensitize the cellular response to Dpp/BMP signaling during Drosophila development. Mechanistically, our results show that Integrator forms a multi-subunit complex with the type I receptor Thickveins (Tkv) and other Dpp/BMP signaling components and acts in a negative feedback loop to promote Tkv turnover independent of its transcriptional activity. Similarly, human Integrator subunits bind transforming growth factor β (TGF-β)/BMP signaling components and antagonize their activity, suggesting a conserved role of Integrator across metazoans.
Collapse
Affiliation(s)
- Sen Liu
- Temasek Life Sciences Laboratory, 1 Research Link, National University of Singapore, Singapore 117604, Singapore
| | - Gyeong Hun Baeg
- Faculty of Medicine, Macau University of Science and Technology, Avenida Wai Long, Taipa, Macau SAR, China
| | - Ying Yang
- Temasek Life Sciences Laboratory, 1 Research Link, National University of Singapore, Singapore 117604, Singapore
| | - Feng Guang Goh
- Temasek Life Sciences Laboratory, 1 Research Link, National University of Singapore, Singapore 117604, Singapore; Department of Biological Sciences, National University of Singapore, Singapore 117543, Singapore
| | - Hongcun Bao
- The Women's Hospital and Institute of Genetics, School of Medicine, Zhejiang University, Hang Zhou 310058, China
| | - Eric J Wagner
- Department of Biochemistry and Biophysics, Center for RNA Biology, Wilmot Cancer Institute, University of Rochester School of Medicine and Dentistry, KMRB B.9629, Rochester, NY 14642 USA
| | - Xiaohang Yang
- The Women's Hospital and Institute of Genetics, School of Medicine, Zhejiang University, Hang Zhou 310058, China
| | - Yu Cai
- Temasek Life Sciences Laboratory, 1 Research Link, National University of Singapore, Singapore 117604, Singapore; Department of Biological Sciences, National University of Singapore, Singapore 117543, Singapore.
| |
Collapse
|
8
|
Mascibroda LG, Shboul M, Elrod ND, Colleaux L, Hamamy H, Huang KL, Peart N, Singh MK, Lee H, Merriman B, Jodoin JN, Sitaram P, Lee LA, Fathalla R, Al-Rawashdeh B, Ababneh O, El-Khateeb M, Escande-Beillard N, Nelson SF, Wu Y, Tong L, Kenney LJ, Roy S, Russell WK, Amiel J, Reversade B, Wagner EJ. INTS13 variants causing a recessive developmental ciliopathy disrupt assembly of the Integrator complex. Nat Commun 2022; 13:6054. [PMID: 36229431 PMCID: PMC9559116 DOI: 10.1038/s41467-022-33547-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2020] [Accepted: 09/22/2022] [Indexed: 12/24/2022] Open
Abstract
Oral-facial-digital (OFD) syndromes are a heterogeneous group of congenital disorders characterized by malformations of the face and oral cavity, and digit anomalies. Mutations within 12 cilia-related genes have been identified that cause several types of OFD, suggesting that OFDs constitute a subgroup of developmental ciliopathies. Through homozygosity mapping and exome sequencing of two families with variable OFD type 2, we identified distinct germline variants in INTS13, a subunit of the Integrator complex. This multiprotein complex associates with RNA Polymerase II and cleaves nascent RNA to modulate gene expression. We determined that INTS13 utilizes its C-terminus to bind the Integrator cleavage module, which is disrupted by the identified germline variants p.S652L and p.K668Nfs*9. Depletion of INTS13 disrupts ciliogenesis in human cultured cells and causes dysregulation of a broad collection of ciliary genes. Accordingly, its knockdown in Xenopus embryos leads to motile cilia anomalies. Altogether, we show that mutations in INTS13 cause an autosomal recessive ciliopathy, which reveals key interactions between components of the Integrator complex.
Collapse
Affiliation(s)
- Lauren G Mascibroda
- Department of Biochemistry and Molecular Biology, The University of Texas Medical Branch at Galveston, Galveston, TX, 77550, USA
| | - Mohammad Shboul
- Department of Medical Laboratory Sciences, Jordan University of Science and Technology, Irbid, Jordan
| | - Nathan D Elrod
- Department of Biochemistry and Molecular Biology, The University of Texas Medical Branch at Galveston, Galveston, TX, 77550, USA
| | - Laurence Colleaux
- Inserm UMR 1163, Institut Imagine, 24 Boulevard du Montparnasse, 75015, Paris, France
| | - Hanan Hamamy
- Department of Genetic Medicine and Development, University Hospital, Geneva, Switzerland
| | - Kai-Lieh Huang
- Department of Biochemistry and Molecular Biology, The University of Texas Medical Branch at Galveston, Galveston, TX, 77550, USA
- Department of Biochemistry and Biophysics, University of Rochester School of Medicine Dentistry, Rochester, NY, 14642, USA
- Center for RNA Biology, University of Rochester School of Medicine Dentistry, Rochester, NY, 14642, USA
| | - Natoya Peart
- Department of Biochemistry and Molecular Biology, The University of Texas Medical Branch at Galveston, Galveston, TX, 77550, USA
| | - Moirangthem Kiran Singh
- Department of Biochemistry and Molecular Biology, The University of Texas Medical Branch at Galveston, Galveston, TX, 77550, USA
| | - Hane Lee
- Department of Pathology and Laboratory Medicine, Department of Human Genetics, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, 90095, USA
- 3billion, Inc., Seoul, South Korea
| | - Barry Merriman
- Department of Pathology and Laboratory Medicine, Department of Human Genetics, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, 90095, USA
| | - Jeanne N Jodoin
- Department of Cell and Developmental Biology, Vanderbilt University Medical Center, Nashville, TN, 37232, USA
| | - Poojitha Sitaram
- Department of Cell and Developmental Biology, Vanderbilt University Medical Center, Nashville, TN, 37232, USA
| | - Laura A Lee
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, TN, 37232, USA
| | - Raja Fathalla
- National Center for Diabetes, Endocrinology and Genetics, Amman, Jordan
| | - Baeth Al-Rawashdeh
- Faculty of Medicine, Hospital of the University of Jordan, University of Jordan, Amman, Jordan
| | - Osama Ababneh
- Faculty of Medicine, Hospital of the University of Jordan, University of Jordan, Amman, Jordan
| | | | - Nathalie Escande-Beillard
- Department of Medical Genetics, KOÇ University, Istanbul, Turkey
- Institute of Molecular and Cell Biology, A*STAR, Singapore, Singapore
| | - Stanley F Nelson
- Department of Pathology and Laboratory Medicine, Department of Human Genetics, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, 90095, USA
| | - Yixuan Wu
- Department of Biological Sciences, Columbia University, New York, NY, 10027, USA
| | - Liang Tong
- Department of Biological Sciences, Columbia University, New York, NY, 10027, USA
| | - Linda J Kenney
- Department of Biochemistry and Molecular Biology, The University of Texas Medical Branch at Galveston, Galveston, TX, 77550, USA
| | - Sudipto Roy
- Institute of Molecular and Cell Biology, A*STAR, Singapore, Singapore
- Department of Paediatrics, School of Medicine, NUS, Singapore, Singapore
- Department of Biological Sciences, Faculty of Science, NUS, Singapore, Singapore
| | - William K Russell
- Department of Biochemistry and Molecular Biology, The University of Texas Medical Branch at Galveston, Galveston, TX, 77550, USA
| | - Jeanne Amiel
- Service de Génétique, Institut Imagine, 24 Boulevard du Montparnasse, 75015, Paris, France
| | - Bruno Reversade
- Department of Medical Genetics, KOÇ University, Istanbul, Turkey.
- Institute of Molecular and Cell Biology, A*STAR, Singapore, Singapore.
- Department of Paediatrics, School of Medicine, NUS, Singapore, Singapore.
- Smart-Health Initiative, Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia.
- Laboratory of Human Genetics & Therapeutics, Genome Institute of Singapore, A*STAR, Singapore, 137673, Singapore.
| | - Eric J Wagner
- Department of Biochemistry and Molecular Biology, The University of Texas Medical Branch at Galveston, Galveston, TX, 77550, USA.
- Department of Biochemistry and Biophysics, University of Rochester School of Medicine Dentistry, Rochester, NY, 14642, USA.
- Center for RNA Biology, University of Rochester School of Medicine Dentistry, Rochester, NY, 14642, USA.
| |
Collapse
|
9
|
Barbosa DJ, Teixeira V, Duro J, Carvalho AX, Gassmann R. Dynein-dynactin segregate meiotic chromosomes in C. elegans spermatocytes. Development 2021; 148:dev.197780. [PMID: 33462114 DOI: 10.1242/dev.197780] [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: 10/19/2020] [Accepted: 01/05/2021] [Indexed: 11/20/2022]
Abstract
The microtubule motor cytoplasmic dynein 1 (dynein) and its essential activator dynactin have conserved roles in spindle assembly and positioning during female meiosis and mitosis, but their contribution to male meiosis remains poorly understood. Here, we characterize the G33S mutation in the C. elegans dynactin subunit DNC-1, which corresponds to G59S in human p150Glued that causes motor neuron disease. In spermatocytes, dnc-1(G33S) delays spindle assembly and penetrantly inhibits anaphase spindle elongation in meiosis I, which prevents the segregation of homologous chromosomes. By contrast, chromosomes segregate without errors in the early dnc-1(G33S) embryo. Deletion of the DNC-1 N-terminus shows that defective meiosis in dnc-1(G33S) spermatocytes is not due to the inability of DNC-1 to interact with microtubules. Instead, our results suggest that the DNC-1(G33S) protein, which is aggregation prone in vitro, is less stable in spermatocytes than the early embryo, resulting in different phenotypic severity in the two dividing tissues. Thus, the dnc-1(G33S) mutant reveals that dynein-dynactin drive meiotic chromosome segregation in spermatocytes and illustrates that the extent to which protein misfolding leads to loss of function can vary significantly between cell types.
Collapse
Affiliation(s)
- Daniel J Barbosa
- Instituto de Investigação e Inovação em Saúde - i3S, Universidade do Porto, 4200-135 Porto, Portugal
| | - Vanessa Teixeira
- Instituto de Investigação e Inovação em Saúde - i3S, Universidade do Porto, 4200-135 Porto, Portugal
| | - Joana Duro
- Instituto de Investigação e Inovação em Saúde - i3S, Universidade do Porto, 4200-135 Porto, Portugal
| | - Ana X Carvalho
- Instituto de Investigação e Inovação em Saúde - i3S, Universidade do Porto, 4200-135 Porto, Portugal
| | - Reto Gassmann
- Instituto de Investigação e Inovação em Saúde - i3S, Universidade do Porto, 4200-135 Porto, Portugal
| |
Collapse
|
10
|
Mendoza-Figueroa MS, Tatomer DC, Wilusz JE. The Integrator Complex in Transcription and Development. Trends Biochem Sci 2020; 45:923-934. [PMID: 32800671 DOI: 10.1016/j.tibs.2020.07.004] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Revised: 07/03/2020] [Accepted: 07/17/2020] [Indexed: 12/15/2022]
Abstract
The Integrator complex is conserved across metazoans and controls the fate of many nascent RNAs transcribed by RNA polymerase II (RNAPII). Among the 14 subunits of Integrator is an RNA endonuclease that is crucial for the biogenesis of small nuclear RNAs and enhancer RNAs. Integrator is further employed to trigger premature transcription termination at many protein-coding genes, thereby attenuating gene expression. Integrator thus helps to shape the transcriptome and ensure that genes can be robustly induced when needed. The molecular functions of Integrator subunits beyond the RNA endonuclease remain poorly understood, but some can act independently of the multisubunit complex. We highlight recent molecular insights into Integrator and propose how misregulation of this complex may lead to developmental defects and disease.
Collapse
Affiliation(s)
- María Saraí Mendoza-Figueroa
- Department of Biochemistry and Biophysics, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - Deirdre C Tatomer
- Department of Biochemistry and Biophysics, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - Jeremy E Wilusz
- Department of Biochemistry and Biophysics, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA.
| |
Collapse
|
11
|
Bauerly E, Yi K, Gibson MC. Wampa is a dynein subunit required for axonemal assembly and male fertility in Drosophila. Dev Biol 2020; 463:158-168. [PMID: 32387369 PMCID: PMC8451153 DOI: 10.1016/j.ydbio.2020.04.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Revised: 04/13/2020] [Accepted: 04/14/2020] [Indexed: 01/01/2023]
Abstract
In cilia and flagella, dyneins form complexes which give rise to the inner and outer axonemal arms. Defects in the dynein arms are the leading cause of primary ciliary dyskinesia (PCD), which is characterized by chronic respiratory infections, situs inversus, and sterility. While the pathological features associated with PCD are increasingly well characterized, many of the causative genetic lesions remain elusive. Using Drosophila, here we analyze genetic requirements for wampa (wam), a previously uncharacterized component of the outer dynein arm. While homozygous mutant animals are viable and display no morphological defects, loss of wam results in complete male sterility. Ultrastructural analysis further reveals that wam mutant spermatids lack the axonemal outer dynein arms, which leads to a complete loss of flagellar motility. In addition to a role in outer dynein arm formation, we also uncover other novel microtubule-associated requirements for wam during spermatogenesis, including the regulation of mitochondrial localization and the shaping of the nuclear head. Due to the conserved nature of dyneins, this study advances our understanding of the pathology of PCD and the functional role of dyneins in axoneme formation and other aspects of spermatogenesis.
Collapse
Affiliation(s)
| | - Kexi Yi
- Stowers Institute for Medical Research, Kansas City, MO, 64110, USA
| | - Matthew C Gibson
- Stowers Institute for Medical Research, Kansas City, MO, 64110, USA; Department of Anatomy and Cell Biology, The University of Kansas School of Medicine, Kansas City, KS, 66160, USA.
| |
Collapse
|
12
|
Sabath K, Stäubli ML, Marti S, Leitner A, Moes M, Jonas S. INTS10-INTS13-INTS14 form a functional module of Integrator that binds nucleic acids and the cleavage module. Nat Commun 2020; 11:3422. [PMID: 32647223 PMCID: PMC7347597 DOI: 10.1038/s41467-020-17232-2] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Accepted: 06/18/2020] [Indexed: 11/18/2022] Open
Abstract
The Integrator complex processes 3′-ends of spliceosomal small nuclear RNAs (snRNAs). Furthermore, it regulates transcription of protein coding genes by terminating transcription after unstable pausing. The molecular basis for Integrator’s functions remains obscure. Here, we show that INTS10, Asunder/INTS13 and INTS14 form a separable, functional Integrator module. The structure of INTS13-INTS14 reveals a strongly entwined complex with a unique chain interlink. Unexpected structural homology to the Ku70-Ku80 DNA repair complex suggests nucleic acid affinity. Indeed, the module displays affinity for DNA and RNA but prefers RNA hairpins. While the module plays an accessory role in snRNA maturation, it has a stronger influence on transcription termination after pausing. Asunder/INTS13 directly binds Integrator’s cleavage module via a conserved C-terminal motif that is involved in snRNA processing and required for spermatogenesis. Collectively, our data establish INTS10-INTS13-INTS14 as a nucleic acid-binding module and suggest that it brings cleavage module and target transcripts into proximity. The Integrator complex (INT) is responsible for the 3′-end processing of several classes of non-coding RNAs. Here the authors show that the INTS10-INTS13-INTS14 complex forms a distinct submodule of INT and suggest it facilitates RNA substrate targeting.
Collapse
Affiliation(s)
- Kevin Sabath
- Institute of Molecular Biology and Biophysics, ETH Zurich, Otto-Stern-Weg 5, CH-8093, Zurich, Switzerland
| | - Melanie L Stäubli
- Institute of Molecular Biology and Biophysics, ETH Zurich, Otto-Stern-Weg 5, CH-8093, Zurich, Switzerland
| | - Sabrina Marti
- Institute of Molecular Biology and Biophysics, ETH Zurich, Otto-Stern-Weg 5, CH-8093, Zurich, Switzerland
| | - Alexander Leitner
- Institute of Molecular Systems Biology, ETH Zurich, Zurich, Switzerland
| | - Murielle Moes
- Institute of Molecular Biology and Biophysics, ETH Zurich, Otto-Stern-Weg 5, CH-8093, Zurich, Switzerland
| | - Stefanie Jonas
- Institute of Molecular Biology and Biophysics, ETH Zurich, Otto-Stern-Weg 5, CH-8093, Zurich, Switzerland.
| |
Collapse
|
13
|
Galletta BJ, Ortega JM, Smith SL, Fagerstrom CJ, Fear JM, Mahadevaraju S, Oliver B, Rusan NM. Sperm Head-Tail Linkage Requires Restriction of Pericentriolar Material to the Proximal Centriole End. Dev Cell 2020; 53:86-101.e7. [PMID: 32169161 DOI: 10.1016/j.devcel.2020.02.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Revised: 11/22/2019] [Accepted: 02/07/2020] [Indexed: 01/27/2023]
Abstract
The centriole, or basal body, is the center of attachment between the sperm head and tail. While the distal end of the centriole templates the cilia, the proximal end associates with the nucleus. Using Drosophila, we identify a centriole-centric mechanism that ensures proper proximal end docking to the nucleus. This mechanism relies on the restriction of pericentrin-like protein (PLP) and the pericentriolar material (PCM) to the proximal end of the centriole. PLP is restricted proximally by limiting its mRNA and protein to the earliest stages of centriole elongation. Ectopic positioning of PLP to more distal portions of the centriole is sufficient to redistribute PCM and microtubules along the entire centriole length. This results in erroneous, lateral centriole docking to the nucleus, leading to spermatid decapitation as a result of a failure to form a stable head-tail linkage.
Collapse
Affiliation(s)
- Brian J Galletta
- Cell and Developmental Biology Center, National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA.
| | - Jacob M Ortega
- Cell and Developmental Biology Center, National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Samantha L Smith
- Cell and Developmental Biology Center, National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Carey J Fagerstrom
- Cell and Developmental Biology Center, National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Justin M Fear
- Developmental Genomics Section, Laboratory of Cell and Developmental Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Sharvani Mahadevaraju
- Developmental Genomics Section, Laboratory of Cell and Developmental Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Brian Oliver
- Developmental Genomics Section, Laboratory of Cell and Developmental Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Nasser M Rusan
- Cell and Developmental Biology Center, National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA.
| |
Collapse
|
14
|
Gómez-Orte E, Sáenz-Narciso B, Zheleva A, Ezcurra B, de Toro M, López R, Gastaca I, Nilsen H, Sacristán MP, Schnabel R, Cabello J. Disruption of the Caenorhabditis elegans Integrator complex triggers a non-conventional transcriptional mechanism beyond snRNA genes. PLoS Genet 2019; 15:e1007981. [PMID: 30807579 PMCID: PMC6390993 DOI: 10.1371/journal.pgen.1007981] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Accepted: 01/22/2019] [Indexed: 01/09/2023] Open
Abstract
Gene expression is generally regulated by recruitment of transcription factors and RNA polymerase II (RNAP II) to specific sequences in the gene promoter region. The Integrator complex mediates processing of small nuclear RNAs (snRNAs) as well as the initiation and release of paused RNAP II at specific genes in response to growth factors. Here we show that in C. elegans, disruption of the Integrator complex leads to transcription of genes located downstream of the snRNA loci via a non-conventional transcription mechanism based on the lack of processing of the snRNAs. RNAP II read-through generates long chimeric RNAs containing snRNA, the intergenic region and the mature mRNA of the downstream gene located in sense. These chimeric sn-mRNAs remain as untranslated long non-coding RNAs, in the case of U1- and U2-derived sn-mRNAs, but can be translated to proteins in the case of SL-derived sn-mRNAs. The transcriptional effect caused by disruption of the Integrator complex is not restricted to genes located downstream of the snRNA loci but also affects key regulators of signal transduction such as kinases and phosphatases. Our findings highlight that these transcriptional alterations may be behind the correlation between mutations in the Integrator complex and tumor transformation.
Collapse
Affiliation(s)
- Eva Gómez-Orte
- Oncology Area, CIBIR (Center for Biomedical Research of La Rioja), Logroño, La Rioja, Spain
| | - Beatriz Sáenz-Narciso
- Oncology Area, CIBIR (Center for Biomedical Research of La Rioja), Logroño, La Rioja, Spain
| | - Angelina Zheleva
- Oncology Area, CIBIR (Center for Biomedical Research of La Rioja), Logroño, La Rioja, Spain
| | - Begoña Ezcurra
- Oncology Area, CIBIR (Center for Biomedical Research of La Rioja), Logroño, La Rioja, Spain
| | - María de Toro
- Oncology Area, CIBIR (Center for Biomedical Research of La Rioja), Logroño, La Rioja, Spain
| | - Rosario López
- Scientific Computing Group (GRUCACI), University of La Rioja, Logroño, La Rioja, Spain
| | - Irene Gastaca
- Oncology Area, CIBIR (Center for Biomedical Research of La Rioja), Logroño, La Rioja, Spain
| | - Hilde Nilsen
- Department of Clinical Molecular Biology, Institute of Clinical Medicine, University of Oslo and Akershus University Hospital, Lørenskog, Norway
| | - María P. Sacristán
- Instituto de Biología Molecular y Celular del Cáncer, Centro de Investigación del Cáncer, CSIC-Universidad de Salamanca, Salamanca, Spain
| | - Ralf Schnabel
- Department of Developmental Genetics, Institute of Genetics, Technische Universität Braunschweig, Braunschweig, Germany
| | - Juan Cabello
- Oncology Area, CIBIR (Center for Biomedical Research of La Rioja), Logroño, La Rioja, Spain
- * E-mail:
| |
Collapse
|
15
|
Tovey CA, Tubman CE, Hamrud E, Zhu Z, Dyas AE, Butterfield AN, Fyfe A, Johnson E, Conduit PT. γ-TuRC Heterogeneity Revealed by Analysis of Mozart1. Curr Biol 2018; 28:2314-2323.e6. [PMID: 29983314 PMCID: PMC6065531 DOI: 10.1016/j.cub.2018.05.044] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2017] [Revised: 04/06/2018] [Accepted: 05/16/2018] [Indexed: 12/13/2022]
Abstract
Microtubules are essential for various cell processes [1] and are nucleated by multi-protein γ-tubulin ring complexes (γ-TuRCs) at various microtubule organizing centers (MTOCs), including centrosomes [2-6]. Recruitment of γ-TuRCs to different MTOCs at different times influences microtubule array formation, but how this is regulated remains an open question. It also remains unclear whether all γ-TuRCs within the same organism have the same composition and how any potential heterogeneity might influence γ-TuRC recruitment. MOZART1 (Mzt1) was recently identified as a γ-TuRC component [7, 8] and is conserved in nearly all eukaryotes [6, 9]. Mzt1 has so far been studied in cultured human cells, yeast, and plants; its absence leads to failures in γ-TuRC recruitment and cell division, resulting in cell death [7, 9-15]. Mzt1 is small (∼8.5 kDa), binds directly to core γ-TuRC components [9, 10, 14, 15], and appears to mediate the interaction between γ-TuRCs and proteins that tether γ-TuRCs to MTOCs [9, 15]. Here, we use Drosophila to investigate the function of Mzt1 in a multicellular animal for the first time. Surprisingly, we find that Drosophila Mzt1 is expressed only in the testes and is present in γ-TuRCs recruited to basal bodies, but not to mitochondria, in developing sperm cells. mzt1 mutants are viable but have defects in basal body positioning and γ-TuRC recruitment to centriole adjuncts; sperm formation is affected and mutants display a rapid age-dependent decline in sperm motility and male fertility. Our results reveal that tissue-specific and MTOC-specific γ-TuRC heterogeneity exist in Drosophila and highlight the complexity of γ-TuRC recruitment in a multicellular animal.
Collapse
Affiliation(s)
- Corinne A Tovey
- Department of Zoology, University of Cambridge, Downing Street, Cambridge CB2 3EJ, UK
| | - Chloe E Tubman
- Department of Zoology, University of Cambridge, Downing Street, Cambridge CB2 3EJ, UK
| | - Eva Hamrud
- Department of Zoology, University of Cambridge, Downing Street, Cambridge CB2 3EJ, UK
| | - Zihan Zhu
- Department of Zoology, University of Cambridge, Downing Street, Cambridge CB2 3EJ, UK
| | - Anna E Dyas
- Department of Zoology, University of Cambridge, Downing Street, Cambridge CB2 3EJ, UK
| | - Andrew N Butterfield
- Department of Zoology, University of Cambridge, Downing Street, Cambridge CB2 3EJ, UK
| | - Alex Fyfe
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, UK
| | - Errin Johnson
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, UK
| | - Paul T Conduit
- Department of Zoology, University of Cambridge, Downing Street, Cambridge CB2 3EJ, UK.
| |
Collapse
|
16
|
Wu CH, Zong Q, Du AL, Zhang W, Yao HC, Yu XQ, Wang YF. Knockdown of Dynamitin in testes significantly decreased male fertility in Drosophila melanogaster. Dev Biol 2016; 420:79-89. [DOI: 10.1016/j.ydbio.2016.10.007] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2016] [Revised: 10/09/2016] [Accepted: 10/09/2016] [Indexed: 10/20/2022]
|
17
|
Rienzo M, Casamassimi A. Integrator complex and transcription regulation: Recent findings and pathophysiology. BIOCHIMICA ET BIOPHYSICA ACTA 2016; 1859:1269-80. [PMID: 27427483 DOI: 10.1016/j.bbagrm.2016.07.008] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2016] [Revised: 07/08/2016] [Accepted: 07/12/2016] [Indexed: 12/20/2022]
Abstract
In the last decade, a novel molecular complex has been added to the RNA polymerase II-mediated transcription machinery as one of the major components. This multiprotein complex, named Integrator, plays a pivotal role in the regulation of most RNA Polymerase II-dependent genes. This complex consists of at least 14 different subunits. However, studies investigating its structure and composition are still lacking. Although it was originally discovered as a complex implicated in the 3'-end formation of noncoding small nuclear RNAs, recent studies indicate additional roles for Integrator in transcription regulation, for example during transcription pause-release and elongation of polymerase, in the biogenesis of transcripts derived from enhancers, as well as in DNA and RNA metabolism for some of its components. Noteworthy, several subunits have been emerging to play roles during development and differentiation; more importantly, their alterations are likely to be involved in several human pathologies, including cancer and lung diseases.
Collapse
Affiliation(s)
- Monica Rienzo
- Department of Biochemistry, Biophysics and General Pathology, Second University of Naples, Via L. De Crecchio 7, 80138 Naples, Italy
| | - Amelia Casamassimi
- Department of Biochemistry, Biophysics and General Pathology, Second University of Naples, Via L. De Crecchio 7, 80138 Naples, Italy.
| |
Collapse
|
18
|
Lee SW, Wu LSH, Huang GM, Huang KY, Lee TY, Weng JTY. Gene expression profiling identifies candidate biomarkers for active and latent tuberculosis. BMC Bioinformatics 2016; 17 Suppl 1:3. [PMID: 26818387 PMCID: PMC4895247 DOI: 10.1186/s12859-015-0848-x] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
BACKGROUND Tuberculosis (TB) is a serious infectious disease in that 90% of those latently infected with Mycobacterium tuberculosis present no symptoms, but possess a 10% lifetime chance of developing active TB. To prevent the spread of the disease, early diagnosis is crucial. However, current methods of detection require improvement in sensitivity, efficiency or specificity. In the present study, we conducted a microarray experiment, comparing the gene expression profiles in the peripheral blood mononuclear cells among individuals with active TB, latent infection, and healthy conditions in a Taiwanese population. RESULTS Bioinformatics analysis revealed that most of the differentially expressed genes belonged to immune responses, inflammation pathways, and cell cycle control. Subsequent RT-PCR validation identified four differentially expressed genes, NEMF, ASUN, DHX29, and PTPRC, as potential biomarkers for the detection of active and latent TB infections. Receiver operating characteristic analysis showed that the expression level of PTPRC may discriminate active TB patients from healthy individuals, while ASUN could differentiate between the latent state of TB infection and healthy condidtion. In contrast, DHX29 may be used to identify latently infected individuals among active TB patients or healthy individuals. To test the concept of using these biomarkers as diagnostic support, we constructed classification models using these candidate biomarkers and found the Naïve Bayes-based model built with ASUN, DHX29, and PTPRC to yield the best performance. CONCLUSIONS Our study demonstrated that gene expression profiles in the blood can be used to identify not only active TB patients, but also to differentiate latently infected patients from their healthy counterparts. Validation of the constructed computational model in a larger sample size would confirm the reliability of the biomarkers and facilitate the development of a cost-effective and sensitive molecular diagnostic platform for TB.
Collapse
Affiliation(s)
- Shih-Wei Lee
- Taoyuan General Hospital, Ministry of Health and Welfare, Taoyuan, Taiwan. .,Department of Life Sciences, National Central University, Taoyuan, Taiwan.
| | | | - Guan-Mau Huang
- Department of Computer Science and Engineering, Yuan Ze University, Taoyuan, Taiwan.
| | - Kai-Yao Huang
- Department of Computer Science and Engineering, Yuan Ze University, Taoyuan, Taiwan.
| | - Tzong-Yi Lee
- Department of Computer Science and Engineering, Yuan Ze University, Taoyuan, Taiwan. .,Innovation Center for Big Data and Digital Convergence, Yuan Ze University, Taoyuan, Taiwan.
| | - Julia Tzu-Ya Weng
- Department of Computer Science and Engineering, Yuan Ze University, Taoyuan, Taiwan. .,Innovation Center for Big Data and Digital Convergence, Yuan Ze University, Taoyuan, Taiwan.
| |
Collapse
|
19
|
Steinhauer J. Separating from the pack: Molecular mechanisms of Drosophila spermatid individualization. SPERMATOGENESIS 2015; 5:e1041345. [PMID: 26413413 PMCID: PMC4581072 DOI: 10.1080/21565562.2015.1041345] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/27/2015] [Revised: 03/26/2015] [Accepted: 03/26/2015] [Indexed: 12/18/2022]
|
20
|
Chen YN, Wu CH, Zheng Y, Li JJ, Wang JL, Wang YF. Knockdown of ATPsyn-b caused larval growth defect and male infertility in Drosophila. ARCHIVES OF INSECT BIOCHEMISTRY AND PHYSIOLOGY 2015; 88:144-154. [PMID: 25336344 DOI: 10.1002/arch.21209] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The ATPsyn-b encoding for subunit b of ATP synthase in Drosophila melanogaster is proposed to act in ATP synthesis and phagocytosis, and has been identified as one of the sperm proteins in both Drosophila and mammals. At present, its details of functions in animal growth and spermatogenesis have not been reported. In this study, we knocked down ATPsyn-b using Drosophila lines expressing inducible hairpin RNAi constructs and Gal4 drivers. Ubiquitous knockdown of ATPsyn-b resulted in growth defects in larval stage as the larvae did not grow bigger than the size of normal second-instar larvae. Knockdown in testes did not interrupt the developmental excursion to viable adult flies, however, these male adults were sterile. Analyses of testes revealed disrupted nuclear bundles during spermatogenesis and abnormal shaping in spermatid elongation. There were no mature sperm in the seminal vesicle of ATPsyn-b knockdown male testes. These findings suggest us that ATPsyn-b acts in growth and male fertility of Drosophila.
Collapse
Affiliation(s)
- Ya-Na Chen
- Hubei Key Laboratory of Genetic Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, Wuhan, Hubei, P. R. China
| | | | | | | | | | | |
Collapse
|
21
|
Yamamoto A. Gathering up meiotic telomeres: a novel function of the microtubule-organizing center. Cell Mol Life Sci 2014; 71:2119-34. [PMID: 24413667 PMCID: PMC11113538 DOI: 10.1007/s00018-013-1548-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2013] [Revised: 12/12/2013] [Accepted: 12/19/2013] [Indexed: 11/26/2022]
Abstract
During meiosis, telomeres cluster and promote homologous chromosome pairing. Telomere clustering depends on conserved SUN and KASH domain nuclear membrane proteins, which form a complex called the linker of nucleoskeleton and cytoskeleton (LINC) and connect telomeres with the cytoskeleton. It has been thought that LINC-mediated cytoskeletal forces induce telomere clustering. However, how cytoskeletal forces induce telomere clustering is not fully understood. Recent study of fission yeast has shown that the LINC complex forms the microtubule-organizing center (MTOC) at the telomere, which has been designated as the "telocentrosome", and that microtubule motors gather telomeres via telocentrosome-nucleated microtubules. This MTOC-dependent telomere clustering might be conserved in other eukaryotes. Furthermore, the MTOC-dependent clustering mechanism appears to function in various other biological events. This review presents an overview of the current understanding of the mechanism of meiotic telomere clustering and discusses the universality of the MTOC-dependent clustering mechanism.
Collapse
Affiliation(s)
- Ayumu Yamamoto
- Department of Chemistry, Graduate School of Science, Shizuoka University, 836 Ohya, Suruga-ku, Sizuoka, 422-8529, Japan,
| |
Collapse
|
22
|
Sitaram P, Hainline SG, Lee LA. Cytological analysis of spermatogenesis: live and fixed preparations of Drosophila testes. J Vis Exp 2014:e51058. [PMID: 24473184 DOI: 10.3791/51058] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Drosophila melanogaster is a powerful model system that has been widely used to elucidate a variety of biological processes. For example, studies of both the female and male germ lines of Drosophila have contributed greatly to the current understanding of meiosis as well as stem cell biology. Excellent protocols are available in the literature for the isolation and imaging of Drosophila ovaries and testes(3-12). Herein, methods for the dissection and preparation of Drosophila testes for microscopic analysis are described with an accompanying video demonstration. A protocol for isolating testes from the abdomen of adult males and preparing slides of live tissue for analysis by phase-contrast microscopy as well as a protocol for fixing and immunostaining testes for analysis by fluorescence microscopy are presented. These techniques can be applied in the characterization of Drosophila mutants that exhibit defects in spermatogenesis as well as in the visualization of subcellular localizations of proteins.
Collapse
Affiliation(s)
- Poojitha Sitaram
- Department of Cell and Developmental Biology, Vanderbilt University Medical Center
| | | | | |
Collapse
|
23
|
Jodoin JN, Shboul M, Albrecht TR, Lee E, Wagner EJ, Reversade B, Lee LA. The snRNA-processing complex, Integrator, is required for ciliogenesis and dynein recruitment to the nuclear envelope via distinct mechanisms. Biol Open 2013; 2:1390-6. [PMID: 24285713 PMCID: PMC3863424 DOI: 10.1242/bio.20136981] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
We previously reported that the small nuclear RNA processing complex, Integrator, is required for dynein recruitment to the nuclear envelope at mitotic onset in cultured human cells. We now report an additional role for INT in ciliogenesis. Depletion of INT subunits from cultured human cells results in loss of primary cilia. We provide evidence that the requirements for INT in dynein localization and ciliogenesis are uncoupled: proteins essential for ciliogenesis are not essential for dynein recruitment to the nuclear envelope, while depletion of known regulators of perinuclear dynein has minimal effects on ciliogenesis. Taken together, our data support a model in which INT ensures proper processing of distinct pools of transcripts encoding components that independently promote perinuclear dynein enrichment and ciliogenesis.
Collapse
Affiliation(s)
- Jeanne N Jodoin
- Department of Cell and Developmental Biology, Vanderbilt University Medical Center, Nashville, TN 37232-8240, USA
| | | | | | | | | | | | | |
Collapse
|
24
|
Sitaram P, Merkle JA, Lee E, Lee LA. asunder is required for dynein localization and dorsal fate determination during Drosophila oogenesis. Dev Biol 2013; 386:42-52. [PMID: 24333177 DOI: 10.1016/j.ydbio.2013.12.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2013] [Revised: 11/19/2013] [Accepted: 12/04/2013] [Indexed: 10/25/2022]
Abstract
We previously showed that asunder (asun) is a critical regulator of dynein localization during Drosophila spermatogenesis. Because the expression of asun is much higher in Drosophila ovaries and early embryos than in testes, we herein sought to determine whether ASUN plays roles in oogenesis and/or embryogenesis. We characterized the female germline phenotypes of flies homozygous for a null allele of asun (asun(d93)). We find that asun(d93) females lay very few eggs and contain smaller ovaries with a highly disorganized arrangement of ovarioles in comparison to wild-type females. asun(d93) ovaries also contain a significant number of egg chambers with structural defects. A majority of the eggs laid by asun(d93) females are ventralized to varying degrees, from mild to severe; this ventralization phenotype may be secondary to defective localization of gurken transcripts, a dynein-regulated step, within asun(d93) oocytes. We find that dynein localization is aberrant in asun(d93) oocytes, indicating that ASUN is required for this process in both male and female germ cells. In addition to the loss of gurken mRNA localization, asun(d93) ovaries exhibit defects in other dynein-mediated processes such as migration of nurse cell centrosomes into the oocyte during the early mitotic divisions, maintenance of the oocyte nucleus in the anterior-dorsal region of the oocyte in late-stage egg chambers, and coupling between the oocyte nucleus and centrosomes. Taken together, our data indicate that asun is a critical regulator of dynein localization and dynein-mediated processes during Drosophila oogenesis.
Collapse
Affiliation(s)
- Poojitha Sitaram
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, U-4225 Medical Research Building III, 465 21st Avenue South, Nashville, TN 37232-8240, USA
| | - Julie A Merkle
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, U-4225 Medical Research Building III, 465 21st Avenue South, Nashville, TN 37232-8240, USA
| | - Ethan Lee
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, U-4225 Medical Research Building III, 465 21st Avenue South, Nashville, TN 37232-8240, USA
| | - Laura A Lee
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, U-4225 Medical Research Building III, 465 21st Avenue South, Nashville, TN 37232-8240, USA.
| |
Collapse
|
25
|
Jodoin JN, Sitaram P, Albrecht TR, May SB, Shboul M, Lee E, Reversade B, Wagner EJ, Lee LA. Nuclear-localized Asunder regulates cytoplasmic dynein localization via its role in the integrator complex. Mol Biol Cell 2013; 24:2954-65. [PMID: 23904267 PMCID: PMC3771956 DOI: 10.1091/mbc.e13-05-0254] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
A pool of dynein anchored to the nuclear surface mediates many processes at G2/M, although its spatial and temporal regulation is poorly understood. Asunder, a critical regulator of dynein recruitment to the nuclear envelope, works in the nucleus as part of Integrator, an snRNA-processing complex, to mediate this event. We previously reported that Asunder (ASUN) is essential for recruitment of dynein motors to the nuclear envelope (NE) and nucleus–centrosome coupling at the onset of cell division in cultured human cells and Drosophila spermatocytes, although the mechanisms underlying this regulation remain unknown. We also identified ASUN as a functional component of Integrator (INT), a multisubunit complex required for 3′-end processing of small nuclear RNAs. We now provide evidence that ASUN acts in the nucleus in concert with other INT components to mediate recruitment of dynein to the NE. Knockdown of other individual INT subunits in HeLa cells recapitulates the loss of perinuclear dynein in ASUN–small interfering RNA cells. Forced localization of ASUN to the cytoplasm via mutation of its nuclear localization sequence blocks its capacity to restore perinuclear dynein in both cultured human cells lacking ASUN and Drosophila asun spermatocytes. In addition, the levels of several INT subunits are reduced at G2/M when dynein is recruited to the NE, suggesting that INT does not directly mediate this step. Taken together, our data support a model in which a nuclear INT complex promotes recruitment of cytoplasmic dynein to the NE, possibly via a mechanism involving RNA processing.
Collapse
Affiliation(s)
- Jeanne N Jodoin
- Department of Cell and Developmental Biology, Vanderbilt University Medical Center, Nashville, TN 37232-8240 Department of Biochemistry and Molecular Biology, University of Texas Medical School at Houston, Houston, TX 77030 Institute of Medical Biology, A*STAR, Singapore 138648 Department of Pediatrics, National University of Singapore, Singapore 119228
| | | | | | | | | | | | | | | | | |
Collapse
|
26
|
Volpi S, Bongiorni S, Fabbretti F, Wakimoto BT, Prantera G. Drosophila rae1 is required for male meiosis and spermatogenesis. J Cell Sci 2013; 126:3541-51. [PMID: 23788425 DOI: 10.1242/jcs.111328] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Previous studies of RAE1, a conserved WD40 protein, in Schizosaccharomyces pombe and mouse revealed a role in mRNA export and cell cycle progression in mitotic cells. Studies of RAE1 in Drosophila showed that the protein localizes to the nuclear envelope and is required for progression through the G1 phase of the cell cycle but not RNA export in tissue culture cells. Drosophila RAE1 also plays an essential developmental role, as it is required for viability and synaptic growth regulation as a component of an E3 ubiquitin ligase complex. Here we describe characterization of a new Drosophila rae1 mutant that is viable but results in male sterility. The mutant showed striking defects in primary spermatocyte nuclear integrity, meiotic chromosome condensation, segregation, and spindle morphology. These defects led to a failure to complete meiosis but allowed several aspects of spermatid differentiation to proceed, including axoneme formation and elongation. A GFP-RAE1 fusion protein that rescued most of the cytological defects showed a dynamic localization to the nuclear envelope, chromatin and other structures depending on the stage of spermatogenesis. A role for RAE1 in male meiosis, as well as mitotic cells, was also indicated by the defects induced by expression of rae1-RNAi. These studies in Drosophila provide the first evidence for an essential meiotic role of RAE1, and thus define RAE1 as a protein required for both meiotic and mitotic cell cycles.
Collapse
Affiliation(s)
- Silvia Volpi
- Department of Ecology and Biology, University of Tuscia, Viterbo, Italy
| | | | | | | | | |
Collapse
|
27
|
Burakov AV, Nadezhdina ES. Association of nucleus and centrosome: magnet or velcro? Cell Biol Int 2013; 37:95-104. [DOI: 10.1002/cbin.10016] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2012] [Accepted: 11/12/2012] [Indexed: 12/20/2022]
Affiliation(s)
- Anton V. Burakov
- A.N.Belozersky Institute of Physico-Chemical Biology of Lomonosov Moscow State University; Vorobjevy Gory, 1/40, Moscow 119992 Russia
| | - Elena S. Nadezhdina
- A.N.Belozersky Institute of Physico-Chemical Biology of Lomonosov Moscow State University; Vorobjevy Gory, 1/40, Moscow 119992 Russia
- Institute of Protein Research of Russian Academy of Science; Vavilova ul., 34, Moscow 119333 Russia
| |
Collapse
|
28
|
Chen J, Ezzeddine N, Waltenspiel B, Albrecht TR, Warren WD, Marzluff WF, Wagner EJ. An RNAi screen identifies additional members of the Drosophila Integrator complex and a requirement for cyclin C/Cdk8 in snRNA 3'-end formation. RNA (NEW YORK, N.Y.) 2012; 18:2148-2156. [PMID: 23097424 PMCID: PMC3504667 DOI: 10.1261/rna.035725.112] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2012] [Accepted: 09/17/2012] [Indexed: 06/01/2023]
Abstract
Formation of the 3' end of RNA polymerase II-transcribed snRNAs requires a poorly understood group of proteins called the Integrator complex. Here we used a fluorescence-based read-through reporter that expresses GFP in response to snRNA misprocessing and performed a genome-wide RNAi screen in Drosophila S2 cells to identify novel factors required for snRNA 3'-end formation. In addition to the known Integrator complex members, we identified Asunder and CG4785 as additional Integrator subunits. Functional and biochemical experiments revealed that Asunder and CG4785 are additional core members of the Integrator complex. We also identified a conserved requirement in both fly and human snRNA 3'-end processing for cyclin C and Cdk8 that is distinct from their function in the Mediator Cdk8 module. Moreover, we observed biochemical association between Integrator proteins and cyclin C/Cdk8, and that overexpression of a kinase-dead Cdk8 causes snRNA misprocessing. These data functionally define the Drosophila Integrator complex and demonstrate an additional function for cyclin C/Cdk8 unrelated to its function in Mediator.
Collapse
Affiliation(s)
- Jiandong Chen
- Department of Biochemistry and Molecular Biology, The University of Texas Medical School at Houston, Houston, Texas 77030, USA
- The University of Texas Graduate School of Biomedical Sciences at Houston, Houston, Texas 77030, USA
| | - Nader Ezzeddine
- Department of Biochemistry and Molecular Biology, The University of Texas Medical School at Houston, Houston, Texas 77030, USA
| | - Bernhard Waltenspiel
- Comparative Genomics Centre, School of Pharmacy and Molecular Sciences, James Cook University, Townsville QLD 4811, Queensland, Australia
| | - Todd R. Albrecht
- Department of Biochemistry and Molecular Biology, The University of Texas Medical School at Houston, Houston, Texas 77030, USA
| | - William D. Warren
- Comparative Genomics Centre, School of Pharmacy and Molecular Sciences, James Cook University, Townsville QLD 4811, Queensland, Australia
| | - William F. Marzluff
- Department of Biochemistry and Biophysics, Program in Molecular Biology and Biotechnology, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
| | - Eric J. Wagner
- Department of Biochemistry and Molecular Biology, The University of Texas Medical School at Houston, Houston, Texas 77030, USA
- The University of Texas Graduate School of Biomedical Sciences at Houston, Houston, Texas 77030, USA
| |
Collapse
|
29
|
Jodoin JN, Shboul M, Sitaram P, Zein-Sabatto H, Reversade B, Lee E, Lee LA. Human Asunder promotes dynein recruitment and centrosomal tethering to the nucleus at mitotic entry. Mol Biol Cell 2012; 23:4713-24. [PMID: 23097494 PMCID: PMC3521680 DOI: 10.1091/mbc.e12-07-0558] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Recruitment of dynein motors to the nuclear surface is an essential step for nucleus-centrosome coupling in prophase. In cultured human cells, this dynein pool is anchored to nuclear pore complexes through RanBP2-Bicaudal D2 (BICD2) and Nup133- centromere protein F (CENP-F) networks. We previously reported that the asunder (asun) gene is required in Drosophila spermatocytes for perinuclear dynein localization and nucleus-centrosome coupling at G2/M of male meiosis. We show here that male germline expression of mammalian Asunder (ASUN) protein rescues asun flies, demonstrating evolutionary conservation of function. In cultured human cells, we find that ASUN down-regulation causes reduction of perinuclear dynein in prophase of mitosis. Additional defects after loss of ASUN include nucleus-centrosome uncoupling, abnormal spindles, and multinucleation. Coimmunoprecipitation and overlapping localization patterns of ASUN and lissencephaly 1 (LIS1), a dynein adaptor, suggest that ASUN interacts with dynein in the cytoplasm via LIS1. Our data indicate that ASUN controls dynein localization via a mechanism distinct from that of either BICD2 or CENP-F. We present a model in which ASUN promotes perinuclear enrichment of dynein at G2/M that facilitates BICD2- and CENP-F-mediated anchoring of dynein to nuclear pore complexes.
Collapse
Affiliation(s)
- Jeanne N Jodoin
- Department of Cell and Developmental Biology, Vanderbilt University Medical Center, Nashville, TN 37232-8240, USA
| | | | | | | | | | | | | |
Collapse
|
30
|
Sitaram P, Anderson MA, Jodoin JN, Lee E, Lee LA. Regulation of dynein localization and centrosome positioning by Lis-1 and asunder during Drosophila spermatogenesis. Development 2012; 139:2945-54. [PMID: 22764052 DOI: 10.1242/dev.077511] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Dynein, a microtubule motor complex, plays crucial roles in cell-cycle progression in many systems. The LIS1 accessory protein directly binds dynein, although its precise role in regulating dynein remains unclear. Mutation of human LIS1 causes lissencephaly, a developmental brain disorder. To gain insight into the in vivo functions of LIS1, we characterized a male-sterile allele of the Drosophila homolog of human LIS1. We found that centrosomes do not properly detach from the cell cortex at the onset of meiosis in most Lis-1 spermatocytes; centrosomes that do break cortical associations fail to attach to the nucleus. In Lis-1 spermatids, we observed loss of attachments between the nucleus, basal body and mitochondria. The localization pattern of LIS-1 protein throughout Drosophila spermatogenesis mirrors that of dynein. We show that dynein recruitment to the nuclear surface and spindle poles is severely reduced in Lis-1 male germ cells. We propose that Lis-1 spermatogenesis phenotypes are due to loss of dynein regulation, as we observed similar phenotypes in flies null for Tctex-1, a dynein light chain. We have previously identified asunder (asun) as another regulator of dynein localization and centrosome positioning during Drosophila spermatogenesis. We now report that Lis-1 is a strong dominant enhancer of asun and that localization of LIS-1 in male germ cells is ASUN dependent. We found that Drosophila LIS-1 and ASUN colocalize and coimmunoprecipitate from transfected cells, suggesting that they function within a common complex. We present a model in which Lis-1 and asun cooperate to regulate dynein localization and centrosome positioning during Drosophila spermatogenesis.
Collapse
Affiliation(s)
- Poojitha Sitaram
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, U-4225 Medical Research Building III, 465 21st Avenue South, Nashville, TN 37232-8240, USA
| | | | | | | | | |
Collapse
|
31
|
Abstract
Drosophila melanogaster spermatids undergo dramatic morphological changes as they differentiate from small round cells approximately 12 μm in diameter into highly polarized, 1.8 mm long, motile sperm capable of participating in fertilization. During spermiogenesis, syncytial cysts of 64 haploid spermatids undergo synchronous differentiation. Numerous changes occur at a subcellular level, including remodeling of existing organelles (mitochondria, nuclei), formation of new organelles (flagellar axonemes, acrosomes), polarization of elongating cysts and plasma membrane addition. At the end of spermatid morphogenesis, organelles, mitochondrial DNA and cytoplasmic components not needed in mature sperm are stripped away in a caspase-dependent process called individualization that results in formation of individual sperm. Here, we review the stages of Drosophila spermiogenesis and examine our current understanding of the cellular and molecular mechanisms involved in shaping male germ cell-specific organelles and forming mature, fertile sperm.
Collapse
Affiliation(s)
- Lacramioara Fabian
- Cell Biology Program; The Hospital for Sick Children (SickKids); Toronto, ON Canada
| | - Julie A. Brill
- Cell Biology Program; The Hospital for Sick Children (SickKids); Toronto, ON Canada
- Department of Molecular Genetics; University of Toronto; Toronto, ON Canada
| |
Collapse
|
32
|
Wainman A, Giansanti MG, Goldberg ML, Gatti M. The Drosophila RZZ complex - roles in membrane trafficking and cytokinesis. J Cell Sci 2012; 125:4014-25. [PMID: 22685323 DOI: 10.1242/jcs.099820] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
The Zw10 protein, in the context of the conserved Rod-Zwilch-Zw10 (RZZ) complex, is a kinetochore component required for proper activity of the spindle assembly checkpoint in both Drosophila and mammals. In mammalian and yeast cells, the Zw10 homologues, together with the conserved RINT1/Tip20p and NAG/Sec39p proteins, form a second complex involved in vesicle transport between Golgi and ER. However, it is currently unknown whether Zw10 and the NAG family member Rod are also involved in Drosophila membrane trafficking. Here we show that Zw10 is enriched at both the Golgi stacks and the ER of Drosophila spermatocytes. Rod is concentrated at the Golgi but not at the ER, whereas Zwilch does not accumulate in any membrane compartment. Mutations in zw10 and RNAi against the Drosophila homologue of RINT1 (rint1) cause strong defects in Golgi morphology and reduce the number of Golgi stacks. Mutations in rod also affect Golgi morphology, whereas zwilch mutants do not exhibit gross Golgi defects. Loss of either Zw10 or Rint1 results in frequent failures of spermatocyte cytokinesis, whereas Rod or Zwilch are not required for this process. Spermatocytes lacking zw10 or rint1 function assemble regular central spindles and acto-myosin rings, but furrow ingression halts prematurely due to defective plasma membrane addition. Collectively, our results suggest that Zw10 and Rint1 cooperate in the ER-Golgi trafficking and in plasma membrane formation during spermatocyte cytokinesis. Our findings further suggest that Rod plays a Golgi-related function that is not required for spermatocyte cytokinesis.
Collapse
Affiliation(s)
- Alan Wainman
- Istituto Pasteur-Fondazione Cenci Bolognetti and Istituto di Biologia e Patologia Molecolari del CNR, Dipartimento di Biologia e Biotecnologie, Sapienza, Università di Roma, P. le A. Moro 5, 00185 Roma, Italy
| | | | | | | |
Collapse
|
33
|
Adolphsen K, Amell A, Havko N, Kevorkian S, Mears K, Neher H, Schwarz D, Schulze SR. Type-I prenyl protease function is required in the male germline of Drosophila melanogaster. G3 (BETHESDA, MD.) 2012; 2:629-42. [PMID: 22690372 PMCID: PMC3362292 DOI: 10.1534/g3.112.002188] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/11/2012] [Accepted: 03/20/2012] [Indexed: 12/23/2022]
Abstract
Many proteins require the addition of a hydrophobic prenyl anchor (prenylation) for proper trafficking and localization in the cell. Prenyl proteases play critical roles in modifying proteins for membrane anchorage. The type I prenyl protease has a defined function in yeast (Ste24p/Afc1p) where it modifies a mating pheromone, and in humans (Zmpste24) where it has been implicated in a disease of premature aging. Despite these apparently very different biological processes, the type I prenyl protease gene is highly conserved, encoded by a single gene in a wide range of animal and plant groups. A notable exception is Drosophila melanogaster, where the gene encoding the type I prenyl protease has undergone an unprecedented series of duplications in the genome, resulting in five distinct paralogs, three of which are organized in a tandem array, and demonstrate high conservation, particularly in the vicinity of the active site of the enzyme. We have undertaken targeted deletion to remove the three tandem paralogs from the genome. The result is a male fertility defect, manifesting late in spermatogenesis. Our results also show that the ancestral type I prenyl protease gene in Drosophila is under strong purifying selection, while the more recent replicates are evolving rapidly. Our rescue data support a role for the rapidly evolving tandem paralogs in the male germline. We propose that potential targets for the male-specific type I prenyl proteases include proteins involved in the very dramatic cytoskeletal remodeling events required for spermatid maturation.
Collapse
Affiliation(s)
- Katie Adolphsen
- Biology Department, Western Washington University, Bellingham, Washington 98225
| | | | | | | | | | | | | | | |
Collapse
|
34
|
Sartain CV, Cui J, Meisel RP, Wolfner MF. The poly(A) polymerase GLD2 is required for spermatogenesis in Drosophila melanogaster. Development 2011; 138:1619-29. [PMID: 21427144 DOI: 10.1242/dev.059618] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The DNA of a developing sperm is normally inaccessible for transcription for part of spermatogenesis in many animals. In Drosophila melanogaster, many transcripts needed for late spermatid differentiation are synthesized in pre-meiotic spermatocytes, but are not translated until later stages. Thus, post-transcriptional control mechanisms are required to decouple transcription and translation during spermatogenesis. In the female germline, developing germ cells accomplish similar decoupling through poly(A) tail alterations to ensure that dormant transcripts are not prematurely translated: a transcript with a short poly(A) tail will remain untranslated, whereas elongating the poly(A) tail permits protein production. In Drosophila, the ovary-expressed cytoplasmic poly(A) polymerase WISPY is responsible for stage-specific poly(A) tail extension in the female germline. Here, we examine the possibility that a recently derived testis-expressed WISPY paralog, GLD2, plays a similar role in the Drosophila male germline. We show that knockdown of Gld2 transcripts causes male sterility, as GLD2-deficient males do not produce mature sperm. Spermatogenesis up to and including meiosis appears normal in the absence of GLD2, but post-meiotic spermatid development rapidly becomes abnormal. Nuclear bundling and F-actin assembly are defective in GLD2 knockdown testes and nuclei fail to undergo chromatin reorganization in elongated spermatids. GLD2 also affects the incorporation of protamines and the stability of dynamin and transition protein transcripts. Our results indicate that GLD2 is an important regulator of late spermatogenesis and is the first example of a Gld-2 family member that plays a significant role specifically in male gametogenesis.
Collapse
Affiliation(s)
- Caroline V Sartain
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, USA
| | | | | | | |
Collapse
|
35
|
Kracklauer MP, Wiora HM, Deery WJ, Chen X, Bolival B, Romanowicz D, Simonette RA, Fuller MT, Fischer JA, Beckingham KM. The Drosophila SUN protein Spag4 cooperates with the coiled-coil protein Yuri Gagarin to maintain association of the basal body and spermatid nucleus. J Cell Sci 2010; 123:2763-72. [PMID: 20647369 DOI: 10.1242/jcs.066589] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Maintaining the proximity of centrosomes to nuclei is important in several cellular contexts, and LINC complexes formed by SUN and KASH proteins are crucial in this process. Here, we characterize the presumed Drosophila ortholog of the mammalian SUN protein, sperm-associated antigen 4 (Spag4, previously named Giacomo), and demonstrate that Spag4 is required for centriole and nuclear attachment during spermatogenesis. Production of spag4 mRNA is limited to the testis, and Spag4 protein shows a dynamic pattern of association with the germline nuclei, including a concentration of protein at the site of attachment of the single spermatid centriole. In the absence of Spag4, nuclei and centrioles or basal bodies (BBs) dissociate from each other after meiosis. This role of Spag4 in centriolar attachment does not involve either of the two KASH proteins of the Drosophila genome (Klarsicht and MSP-300), but does require the coiled-coil protein Yuri Gagarin. Yuri shows an identical pattern of localization at the nuclear surface to Spag4 during spermatogenesis, and epistasis studies show that the activities of Yuri and dynein-dynactin are downstream of spag4 in this centriole attachment pathway. The later defects in spermatogenesis seen for yuri and spag4 mutants are similar, suggesting they could be secondary to initial disruption of events at the nuclear surface.
Collapse
Affiliation(s)
- Martin P Kracklauer
- Institute for Cell and Molecular Biology and Section of Cell and Developmental Biology, The University of Texas at Austin, Austin, TX 78712, USA
| | | | | | | | | | | | | | | | | | | |
Collapse
|