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Sellin ME, Stenmark S, Gullberg M. Cell type-specific expression of SEPT3-homology subgroup members controls the subunit number of heteromeric septin complexes. Mol Biol Cell 2014; 25:1594-607. [PMID: 24648497 PMCID: PMC4019491 DOI: 10.1091/mbc.e13-09-0553] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Heteromeric septin complexes serve as building blocks of filaments that organize the cortex of fungal and animal cells. This report addresses determinants that direct hetero-oligomerization of the 13 septin paralogues of mammals. It shows that three distinct septins direct assembly of tissue-specific heterotetramers. Septins are filament-forming proteins important for organizing the cortex of animal and fungal cells. In mammals, 13 septin paralogues were recently shown to assemble into core heterohexamer and heterooctamer complexes, which serve as building blocks for apolar filamentous structures that differ among cell types. To determine how tissue-specific septin paralogue expression may shape core heteromer repertoires and thereby modulate properties of septin filaments, we devised protocols to analyze native septin heteromers with distinct numbers of subunits. Our evidence based on genetically manipulated human cells supports and extends recent concepts of homology subgroup–restricted assembly into distinct categories of apolar heterohexamers and heterooctamers. We also identify a category of tetramers that have a subunit composition equivalent to an octameric building block. These atypical tetramers are prevalent in lymphocytes and neural tissues, in which octamers are abundant but hexamers are rare. Our results can be explained by tissue-specific expression of SEPT3 subgroup members: SEPT3, SEPT9, and SEPT12. These serve as cognate subunits in either heterooctamers or atypical tetramers but exhibit different preferences in various tissues. The identified tissue-specific repertoires of septin heteromers provide insights into how higher-order septin structures with differential properties and stabilities may form in diverse animal cell types.
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Affiliation(s)
- Mikael E Sellin
- Department of Molecular Biology, Umeå University, SE-901 87 Umeå, SwedenInstitute of Microbiology, D-BIOL, ETH Zürich, 8093 Zürich, Switzerland
| | - Sonja Stenmark
- Department of Molecular Biology, Umeå University, SE-901 87 Umeå, Sweden
| | - Martin Gullberg
- Department of Molecular Biology, Umeå University, SE-901 87 Umeå, Sweden
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Shafipour M, Sabbaghian M, Shahhoseini M, Sadighi Gilani MA. Comparative expression analysis of Septin 14 in testes of infertile men with normal spermatogenesis and spermatogenic failure. IRANIAN JOURNAL OF REPRODUCTIVE MEDICINE 2014; 12:205-8. [PMID: 24799881 PMCID: PMC4009572] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/26/2013] [Accepted: 09/18/2013] [Indexed: 11/16/2022]
Abstract
BACKGROUND Septins are an evolutionary conserved group of GTP-binding and filament-forming proteins that have diverse cellular roles. An increasing body of data implicates the septin family in the pathogenesis of diverse states including cancers, neurodegeneration, and male infertility. OBJECTIVE The objective of the study was to evaluate the expression pattern of Septin14 in testis tissue of men with and without spermatogenic failure. MATERIALS AND METHODS The samples retrieved accessible random between infertile men who underwent diagnostic testicular biopsy in Royan institute. 10 infertile men with obstructive azoospermia and normal spermatogenesis and 20 infertile men with non-obstructive azoospermia were recruited for real-time reverse transcription (RT)-PCR analysis of the testicular tissue. Total RNA was extracted with trizol reagent. RESULTS Comparison of the mRNA level of septin14 revealed that in tissues with partial (n=10) or complete spermatogenesis (n=10), the expression of septin 14 was significantly higher than sertoli cell only tissues. CONCLUSION The testicular tissues of men with hypospermatogenesis, maturation arrest and sertoli cell only had lower levels of septin 14 transcripts than normal men. These data indicates that Septin 14 expression level is critical for human spermatogenesis.
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Affiliation(s)
- Maryam Shafipour
- Department of Andrology, Reproductive Biomedicine Research Center, Royan Institute, ACECR, Tehran, Iran.
| | - Marjan Sabbaghian
- Department of Andrology, Reproductive Biomedicine Research Center, Royan Institute, ACECR, Tehran, Iran.
| | - Maryam Shahhoseini
- Department of Reproductive Genetics, Reproductive Biomedicine Research Center, Royan Institute, ACECR, Tehran, Iran.
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Zeraik AE, Rinaldi G, Mann VH, Popratiloff A, Araujo APU, DeMarco R, Brindley PJ. Septins of Platyhelminths: identification, phylogeny, expression and localization among developmental stages of Schistosoma mansoni. PLoS Negl Trop Dis 2013; 7:e2602. [PMID: 24367716 PMCID: PMC3868516 DOI: 10.1371/journal.pntd.0002602] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2013] [Accepted: 11/08/2013] [Indexed: 01/19/2023] Open
Abstract
Septins are a family of eukaryotic GTP binding proteins conserved from yeasts to humans. Originally identified in mutants of budding yeast, septins participate in diverse cellular functions including cytokinesis, organization of actin networks, cell polarity, vesicle trafficking and many others. Septins assemble into heteroligomers to form filaments and rings. Here, four septins of Schistosoma mansoni are described, which appear to be conserved within the phylum Platyhelminthes. These orthologues were related to the SEPT5, SEPT10 and SEPT7 septins of humans, and hence we have termed the schistosome septins SmSEPT5, SmSEPT10, SmSEPT7.1 and SmSEPT7.2. Septin transcripts were detected throughout the developmental cycle of the schistosome and a similar expression profile was observed for septins in the stages examined, consistent with concerted production of these proteins to form heterocomplexes. Immunolocalization analyses undertaken with antibodies specific for SmSEPT5 and SmSEPT10 revealed a broad tissue distribution of septins in the schistosomulum and colocalization of septin and actin in the longitudinal and circular muscles of the sporocyst. Ciliated epidermal plates of the miracidium were rich in septins. Expression levels for these septins were elevated in germ cells in the miracidium and sporocyst. Intriguingly, septins colocalize with the protonephridial system of the cercaria, which extends laterally along the length of this larval stage. Together, the findings revealed that schistosomes expressed several septins which likely form filaments within the cells, as in other eukaryotes. Identification and localization demonstrating a broad distribution of septins across organs and tissues of schistosome contributes towards the understanding of septins in schistosomes and other flatworms.
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Affiliation(s)
- Ana E. Zeraik
- Departamento de Física e Informática, Instituto de Física de São Carlos, Universidade de São Paulo, São Carlos, São Paulo, Brazil
- Department of Microbiology, Immunology & Tropical Medicine, and Research Center for Neglected Tropical and Infectious Diseases of Poverty, School of Medicine & Health Sciences, The George Washington University, Washington, D.C., United States of America
| | - Gabriel Rinaldi
- Department of Microbiology, Immunology & Tropical Medicine, and Research Center for Neglected Tropical and Infectious Diseases of Poverty, School of Medicine & Health Sciences, The George Washington University, Washington, D.C., United States of America
- Departamento de Genética, Facultad de Medicina, Universidad de la República (UDELAR), Montevideo, Uruguay
| | - Victoria H. Mann
- Department of Microbiology, Immunology & Tropical Medicine, and Research Center for Neglected Tropical and Infectious Diseases of Poverty, School of Medicine & Health Sciences, The George Washington University, Washington, D.C., United States of America
| | - Anastas Popratiloff
- Center for Microscopy and Image Analysis, The George Washington University, Washington, D.C., United States of America
| | - Ana P. U. Araujo
- Departamento de Física e Informática, Instituto de Física de São Carlos, Universidade de São Paulo, São Carlos, São Paulo, Brazil
| | - Ricardo DeMarco
- Departamento de Física e Informática, Instituto de Física de São Carlos, Universidade de São Paulo, São Carlos, São Paulo, Brazil
- * E-mail: (RDM); (PJB)
| | - Paul J. Brindley
- Department of Microbiology, Immunology & Tropical Medicine, and Research Center for Neglected Tropical and Infectious Diseases of Poverty, School of Medicine & Health Sciences, The George Washington University, Washington, D.C., United States of America
- * E-mail: (RDM); (PJB)
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SEPT12-microtubule complexes are required for sperm head and tail formation. Int J Mol Sci 2013; 14:22102-16. [PMID: 24213608 PMCID: PMC3856054 DOI: 10.3390/ijms141122102] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2013] [Revised: 09/26/2013] [Accepted: 09/26/2013] [Indexed: 11/17/2022] Open
Abstract
The septin gene belongs to a highly conserved family of polymerizing GTP-binding cytoskeletal proteins. SEPTs perform cytoskeletal remodeling, cell polarity, mitosis, and vesicle trafficking by interacting with various cytoskeletons. Our previous studies have indicated that SEPTIN12+/+/+/- chimeras with a SEPTIN12 mutant allele were infertile. Spermatozoa from the vas deferens of chimeric mice indicated an abnormal sperm morphology, decreased sperm count, and immotile sperm. Mutations and genetic variants of SEPTIN12 in infertility cases also caused oligozoospermia and teratozoospermia. We suggest that a loss of SEPT12 affects the biological function of microtublin functions and causes spermiogenesis defects. In the cell model, SEPT12 interacts with α- and β-tubulins by co-immunoprecipitation (co-IP). To determine the precise localization and interactions between SEPT12 and α- and β-tubulins in vivo, we created SEPTIN12-transgene mice. We demonstrate how SEPT12 interacts and co-localizes with α- and β-tubulins during spermiogenesis in these mice. By using shRNA, the loss of SEPT12 transcripts disrupts α- and β-tubulin organization. In addition, losing or decreasing SEPT12 disturbs the morphogenesis of sperm heads and the elongation of sperm tails, the steps of which are coordinated and constructed by α- and β-tubulins, in SEPTIN12+/+/+/- chimeras. In this study, we discovered that the SEPTIN12-microtubule complexes are critical for sperm formation during spermiogenesis.
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Tartakoff AM, Aylyarov I, Jaiswal P. Septin-containing barriers control the differential inheritance of cytoplasmic elements. Cell Rep 2012; 3:223-36. [PMID: 23273916 DOI: 10.1016/j.celrep.2012.11.022] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2012] [Revised: 09/27/2012] [Accepted: 11/27/2012] [Indexed: 01/12/2023] Open
Abstract
Fusion of haploid cells of Saccharomyces cerevisiae generates zygotes. We observe that the zygote midzone includes a septin annulus and differentially affects redistribution of supramolecular complexes and organelles. Redistribution across the midzone of supramolecular complexes (polysomes and Sup35p-GFP [PSI+]) is unexpectedly delayed relative to soluble proteins; however, in [psi-] × [PSI+] crosses, all buds eventually receive Sup35p-GFP [PSI+]. Encounter between parental mitochondria is further delayed until septins relocate to the bud site, where they are required for repolarization of the actin cytoskeleton. This delay allows rationalization of the longstanding observation that terminal zygotic buds preferentially inherit a single mitochondrial genotype. The rate of redistribution of complexes and organelles determines whether their inheritance will be uniform.
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Affiliation(s)
- Alan Michael Tartakoff
- Pathology Department and Cell Biology Program, Case Western Reserve University, 2103 Cornell Road, Cleveland, OH 44106, USA.
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Li S, Ou XH, Wei L, Wang ZB, Zhang QH, Ouyang YC, Hou Y, Schatten H, Sun QY. Septin 7 is required for orderly meiosis in mouse oocytes. Cell Cycle 2012; 11:3211-8. [PMID: 22895176 DOI: 10.4161/cc.21553] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Septin 7 is a conserved GTP-binding protein. In this study, we examined the localization and functions of Septin 7 during mouse oocyte meiotic maturation. Immunofluorescent analysis showed that intrinsic Septin 7 localized to the spindles from the pro-MI stage to the MII stage. Knockdown of Septin 7 by siRNA microinjection caused abnormal spindles and affected extrusion of the first polar body. Septin 7 mRNA tagged with myc was injected into GV stage oocytes to overexpress Septin 7. Overexpressed Myc-Septin 7 localized to the spindle and beneath the plasma membrane displaying long filaments. Fluorescence intensity of spindle α-tubulin in myc-Septin 7-injected oocytes was weaker than that of the control group, demonstrating that Septin 7 may influence recruitment of α-tubulin to spindles. MII oocytes injected with myc-Septin 7 exhibited abnormal chromosome alignment, and parthenogenetic activation failed to allow extrusion of the second polar body, suggesting that overexpression of Septin 7 may affect extrusion of the polar body by disturbing the alignment of chromosomes and regulating α-tubulin recruitment to spindles. In summary, Septin 7 may regulate meiotic cell cycle progression by affecting microtubule cytoskeletal dynamics in mouse oocytes.
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Affiliation(s)
- Sen Li
- State Key Laboratory of Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Reproductive Medicine Center, Peking University People's Hospital, Beijing, China
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Yan Q, Wu X, Chen C, Diao R, Lai Y, Huang J, Chen J, Yu Z, Gui Y, Tang A, Cai Z. Developmental expression and function of DKKL1/Dkkl1 in humans and mice. Reprod Biol Endocrinol 2012; 10:51. [PMID: 22817830 PMCID: PMC3442974 DOI: 10.1186/1477-7827-10-51] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/16/2012] [Accepted: 06/27/2012] [Indexed: 02/08/2023] Open
Abstract
BACKGROUND Experiments were designed to identify the developmental expression and function of the Dickkopf-Like1 (DKKL1/Dkkl1) gene in humans and mice. METHODS Mouse testes cDNA samples were collected at multiple postnatal times (days 4, 9, 18, 35, and 54, as well as at 6 months) and hybridized to Affymetrix mouse whole genome Genechips. To further characterize the homologous gene DKKL1 in human beings, the expression profiles between human adult testis and foetal testis were compared using Affymetrix human Genechips. The characteristics of DKKL1/Dkkl1 were analysed using various cellular and molecular biotechnologies. RESULTS The expression of Dkkl1 was not detected in mouse testes on days 4 or 9, but was present on days 18, 35, and 54, as well as at 6 months, which was confirmed by RT-PCR and Western blot results. Examination of the tissue distribution of Dkkl1 demonstrated that while Dkkl1 mRNA was abundantly expressed in testes, little to no expression of Dkkl1 was observed in the epididymis or other tissues. In an in vitro fertilization assay, a Dkkl1 antibody was found to significantly reduce fertilization. Human Genechips results showed that the hybridization signal intensity of DKKL1 was 405.56-fold higher in adult testis than in foetal testis. RT-PCR analysis of multiple human tissues indicated that DKKL1 mRNA was exclusively expressed in the testis. Western blot analysis also demonstrated that DKKL1 was mainly expressed in human testis with a molecular weight of approximately 34 kDa. Additionally, immunohistochemical staining showed that the DKKL1 protein was predominantly located in spermatocytes and round spermatids in human testes. An examination of the expression levels of DKKL1 in infertile male patients revealed that while no DKKL1 appeared in the testes of patients with Sertoli cell only syndrome (SCOS) or cryptorchidism, DKKL1 was observed with variable expression in patients with spermatogenic arrest. CONCLUSIONS These results, together with previous studies, suggest that DKKL1/Dkkl1 may play an important role in testicular development and spermatogenesis and may be an important factor in male infertility.
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Affiliation(s)
- Qiuxia Yan
- Center for Reproductive Medicine, Department of Obstetrics and Gynecology, The People's Hospital of Qingyuan, The Fifth Affiliated Hospital of Medical College of Jinan University, Qingyuan, China
| | - Xiaoping Wu
- Institute of Tissue Transplantation and Immunology, Jinan University, Guangzhou, China
| | - Cairong Chen
- Center for Reproductive Medicine, Department of Obstetrics and Gynecology, The People's Hospital of Qingyuan, The Fifth Affiliated Hospital of Medical College of Jinan University, Qingyuan, China
| | - Ruiying Diao
- Guangdong Key Lab of Male Reproductive Medicine and Genetics, Peking University Shenzhen Hospital, Shenzhen, China
| | - Yongqing Lai
- Guangdong Key Lab of Male Reproductive Medicine and Genetics, Peking University Shenzhen Hospital, Shenzhen, China
| | - Jun Huang
- Guangdong Key Lab of Male Reproductive Medicine and Genetics, Peking University Shenzhen Hospital, Shenzhen, China
| | - Jing Chen
- Guangdong Key Lab of Male Reproductive Medicine and Genetics, Peking University Shenzhen Hospital, Shenzhen, China
| | - Zhou Yu
- Guangdong Key Lab of Male Reproductive Medicine and Genetics, Peking University Shenzhen Hospital, Shenzhen, China
| | - Yaoting Gui
- Guangdong Key Lab of Male Reproductive Medicine and Genetics, Peking University Shenzhen Hospital, Shenzhen, China
| | - Aifa Tang
- Shenzhen Second People's Hospital, The First Affiliated Hospital of Shenzhen University, Shenzhen, China
| | - Zhiming Cai
- Shenzhen Second People's Hospital, The First Affiliated Hospital of Shenzhen University, Shenzhen, China
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Affiliation(s)
- Nolan Beise
- Cell Biology Program, Hospital for Sick Children, 555 University Avenue, Toronto, Ontario M5G 1X8, Canada
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Abstract
At present many couples face difficulties when trying to conceive that may have a genetic basis. The male factor is the cause of infertility as often as the female. Therefore it is important to identify key genes involved in spermatogenesis which may be linked to male infertility. This review discusses the identification of a range of genes associated with male fertility using microarrays. Based on differences in gene expression profiles between fertile and infertile male subgroups or between fetal and adult male gonads, many genes important for spermatogenesis have been discovered. Genes that are critical at particular stages of spermatogenesis were defined and can be considered as potential male fertility biomarkers. The studies described showed that microarrays may be potentially used as a diagnostic platform to increase the efficacy of diagnosis and perhaps treatment of infertile males.
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Lin YH, Wang YY, Chen HI, Kuo YC, Chiou YW, Lin HH, Wu CM, Hsu CC, Chiang HS, Kuo PL. SEPTIN12 genetic variants confer susceptibility to teratozoospermia. PLoS One 2012; 7:e34011. [PMID: 22479503 PMCID: PMC3316533 DOI: 10.1371/journal.pone.0034011] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2011] [Accepted: 02/21/2012] [Indexed: 12/16/2022] Open
Abstract
It is estimated that 10-15% of couples are infertile and male factors account for about half of these cases. With the advent of intracytoplasmic sperm injection (ICSI), many infertile men have been able to father offspring. However, teratozoospermia still remains a big challenge to tackle. Septins belong to a family of cytoskeletal proteins with GTPase activity and are involved in various biological processes e.g. morphogenesis, compartmentalization, apoptosis and cytokinesis. SEPTIN12, identified by c-DNA microarray analysis of infertile men, is exclusively expressed in the post meiotic male germ cells. Septin12(+/+)/Septin12(+/-) chimeric mice have multiple reproductive defects including the presence of immature sperm in the semen, and sperm with bent neck (defect of the annulus) and nuclear DNA damage. These facts make SEPTIN12 a potential sterile gene in humans. In this study, we sequenced the entire coding region of SEPTIN12 in infertile men (n = 160) and fertile controls (n = 200) and identified ten variants. Among them is the c.474 G>A variant within exon 5 that encodes part of the GTP binding domain. The variant creates a novel splice donor site that causes skipping of a portion of exon 5, resulting in a truncated protein lacking the C-terminal half of SEPTIN12. Most individuals homozygous for the c.474 A allele had teratozoospermia (abnormal sperm <14%) and their sperm showed bent tail and de-condensed nucleus with significant DNA damage. Ex vivo experiment showed truncated SEPT12 inhibits filament formation in a dose-dependent manner. This study provides the first causal link between SEPTIN12 genetic variant and male infertility with distinctive sperm pathology. Our finding also suggests vital roles of SEPT12 in sperm nuclear integrity and tail development.
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Affiliation(s)
- Ying-Hung Lin
- Graduate Institute of Basic Medicine, Fu Jen Catholic University, College of Medicine, Taipei, Taiwan
| | - Ya-Yun Wang
- Department of Obstetrics & Gynecology, National Cheng Kung University, College of Medicine, Tainan, Taiwan
- Institute of Molecular Medicine, National Cheng Kung University, College of Medicine, Tainan, Taiwan
| | - Hau-Inh Chen
- Department of Biochemistry and Molecular Biology, National Cheng Kung University, College of Medicine, Tainan, Taiwan
| | - Yung-Che Kuo
- Graduate Institute of Basic Medical Sciences, National Cheng Kung University, College of Medicine, Tainan, Taiwan
| | - Yu-Wei Chiou
- Department of Biomedical Engineering, National Cheng Kung University, College of Engineering, Tainan, Taiwan
| | - Hsi-Hui Lin
- Department of Physiology, National Cheng Kung University, College of Medicine, Tainan, Taiwan
| | - Ching-Ming Wu
- Department of Cell Biology & Anatomy, National Cheng Kung University, College of Medicine, Tainan, Taiwan
| | - Chao-Chin Hsu
- Department of Obstetrics and Gynecology, China Medical University, Taichung, Taiwan
| | - Han-Sun Chiang
- Graduate Institute of Basic Medicine, Fu Jen Catholic University, College of Medicine, Taipei, Taiwan
| | - Pao-Lin Kuo
- Department of Obstetrics & Gynecology, National Cheng Kung University, College of Medicine, Tainan, Taiwan
- Department of Biochemistry and Molecular Biology, National Cheng Kung University, College of Medicine, Tainan, Taiwan
- Graduate Institute of Basic Medical Sciences, National Cheng Kung University, College of Medicine, Tainan, Taiwan
- * E-mail:
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Kuo YC, Lin YH, Chen HI, Wang YY, Chiou YW, Lin HH, Pan HA, Wu CM, Su SM, Hsu CC, Kuo PL. SEPT12 mutations cause male infertility with defective sperm annulus. Hum Mutat 2012; 33:710-9. [PMID: 22275165 DOI: 10.1002/humu.22028] [Citation(s) in RCA: 83] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2011] [Accepted: 01/03/2012] [Indexed: 11/11/2022]
Abstract
Septins are members of the GTPase superfamily, which has been implicated in diverse cellular functions including cytokinesis and morphogenesis. Septin 12 (SEPT12) is a testis-specific gene critical for the terminal differentiation of male germ cells. We report the identification of two missense SEPT12 mutations, c.266C>T/p.Thr89Met and c.589G>A/p.Asp197Asn, in infertile men. Both mutations are located inside the GTPase domain and may alter the protein structure as suggested by in silico modeling. The p.Thr89Met mutation significantly reduced guanosine-5'-triphosphate (GTP) hydrolytic activity, and the p.Asp197Asn mutation (SEPT12(D197N)) interfered with GTP binding. Both mutant SEPT12 proteins restricted the filament formation of the wild-type SEPT12 in a dose-dependent manner. The patient carrying SEPT12(D197N) presented with oligoasthenozoospermia, whereas the SEPT12(T89M) patient had asthenoteratozoospermia. The characteristic sperm pathology of the SEPT12(D197N) patient included defective annulus with bent tail and loss of SEPT12 from the annulus of abnormal sperm. Our finding suggests loss-of-function mutations in SEPT12 disrupted sperm structural integrity by perturbing septin filament formation.
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Affiliation(s)
- Yung-Che Kuo
- Graduate Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan, Taiwan
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Miyamoto T, Tsujimura A, Miyagawa Y, Koh E, Namiki M, Horikawa M, Saijo Y, Sengoku K. Single nucleotide polymorphisms in the SEPTIN12 gene may be associated with azoospermia by meiotic arrest in Japanese men. J Assist Reprod Genet 2012; 29:47-51. [PMID: 22116646 PMCID: PMC3252415 DOI: 10.1007/s10815-011-9679-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2011] [Accepted: 11/09/2011] [Indexed: 10/15/2022] Open
Abstract
PURPOSE To investigate the association between SEPTIN12 gene variants and the risk of azoospermia caused by meiotic arrest. METHODS Mutational analysis of the SEPTIN12 gene was performed using DNA from 30 Japanese patients with azoospermia by meiotic arrest and 140 fertile male controls. RESULTS The frequencies of the c.204G>C (Gln38His) allele and the CC genotype were significantly higher in patients than in fertile controls (p < 0.05). CONCLUSION The c.204G>C (Gln38His) variant in the SEPTIN12 gene was associated with increased susceptibility to azoospermia caused by meiotic arrest.
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Affiliation(s)
- Toshinobu Miyamoto
- Department of Obstetrics and Gynecology, Asahikawa Medical University, Midorigaokahigashi 2-1-1-1, Asahikawa, Hokkaido, 078-8510, Japan.
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Lin YH, Kuo YC, Chiang HS, Kuo PL. The role of the septin family in spermiogenesis. SPERMATOGENESIS 2011; 1:298-302. [PMID: 22332113 DOI: 10.4161/spmg.1.4.18326] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2011] [Revised: 09/29/2011] [Accepted: 09/29/2011] [Indexed: 01/08/2023]
Abstract
SEPTINS (FULL NAME: Septin; symbol name: SEPT) belong to a family of polymerizing GTP-binding proteins that are required for many cellular functions, including membrane compartmentalization, vesicle trafficking, mitosis and cytoskeletal remodeling. Two of the 14 family members in the mammalian species, Septin12 and 14 are expressed specifically in the testis. In the mouse, knockout of Septin4 and Septin12 leads to male sterility with distinctive sperm pathology (defective annulus or bent neck). In humans, sperm with abnormal expression patterns of SEPT4, 7 and 12 are more prevalent in infertile men. How septin filament is assembled/dissembled and how the SEPT-related complex regulates spermatogenesis still await further investigation.
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Affiliation(s)
- Ying-Hung Lin
- Graduate Institute of Basic Medicine; Fu Jen Catholic University; Taipei, Taiwan
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Iyengar PV, Hirota T, Hirose S, Nakamura N. Membrane-associated RING-CH 10 (MARCH10 protein) is a microtubule-associated E3 ubiquitin ligase of the spermatid flagella. J Biol Chem 2011; 286:39082-90. [PMID: 21937444 DOI: 10.1074/jbc.m111.256875] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Spermiogenesis is a complex and dynamic process of the metamorphosis of spermatids into spermatozoa. There is a great deal that is still unknown regarding the regulatory mechanisms for the formation of the sperm flagellum. In this study, we determined that the membrane-associated RING-CH 10 (March10) gene is predominantly expressed in rat testis. We isolated two March10 isoforms encoding MARCH10a and MARCH10b, which are generated by alternative splicing. MARCH10a is a long RING finger protein, and MARCH10b is a short RING finger-less protein. Immunohistochemical staining revealed that the MARCH10 proteins are specifically expressed in elongating and elongated spermatids, and the expression is absent in epididymal spermatozoa. MARCH10 immunoreactivity was observed in the cytoplasmic lobes as well as the principal piece and annulus of the flagella. When overexpressed in COS7 cells, MARCH10a was localized along the microtubules, whereas MARCH10b was distributed throughout the cytoplasm. An in vitro microtubule cosedimentation assay showed that MARCH10a is directly associated with microtubules. An in vitro ubiquitination assay demonstrated that the RING finger domain of MARCH10a exhibits an E3 ubiquitin ligase activity along with the E2 ubiquitin-conjugating enzyme UBE2B. Moreover, MARCH10a undergoes proteasomal degradation by autoubiquitination in transfected COS7 cells, but this activity was abolished upon microtubule disassembly. These results suggest that MARCH10 is involved in spermiogenesis by regulating the formation and maintenance of the flagella in developing spermatids.
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Affiliation(s)
- Prasanna Vasudevan Iyengar
- Department of Biological Sciences, Tokyo Institute of Technology, 4259-B-19 Nagatsuta-cho, Midori-ku, Yokohama 226-8501, Japan
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Liu F, Jin S, Li N, Liu X, Wang H, Li J. Comparative and functional analysis of testis-specific genes. Biol Pharm Bull 2011; 34:28-35. [PMID: 21212513 DOI: 10.1248/bpb.34.28] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The testis is the special male gonad responsible for spermatogenesis and steroidogenesis with complex gene expressions. Characterizing and comparing the testis-specific genes in different species can reveal key genes related to testis specific functions and provide supplementary information for study of human testis function. We screened testis-specific genes from Unigene libraries, total 317, 449 and 147 testis-specific genes were identified for human, mouse and rat, respectively. Ten from thirteen selected human testis-specific genes were validated exclusively expressed in the testis by reverse transcription polymerase chain reaction (RT-PCR). Systematic bioinformatics analysis showed that specific genes were mainly related to spermatogenesis and testis development process with significant Glycolysis and Pyruvate metabolism. Enrichment functions were discussed.
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Affiliation(s)
- FuJun Liu
- Shandong Research Centre for Stem Cell Engineering, Yu-Huang-Ding Hospital and Yan-Tai University, Yantai, Shandong Province 264000, PR China
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Lin YH, Chou CK, Hung YC, Yu IS, Pan HA, Lin SW, Kuo PL. SEPT12 deficiency causes sperm nucleus damage and developmental arrest of preimplantation embryos. Fertil Steril 2011; 95:363-5. [PMID: 20801438 DOI: 10.1016/j.fertnstert.2010.07.1064] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2010] [Revised: 07/02/2010] [Accepted: 07/12/2010] [Indexed: 10/19/2022]
Abstract
Oocytes fertilized with spermatozoa obtained from Septin 12+/- chimeric mice failed to develop beyond the morula stage after IVF and intracytoplasmic sperm injection because of significant DNA defects in the spermatozoa. Given that SEPT12 is expressed at the edge of the sperm nucleus in both humans and mice, we hypothesized the vital roles of Septin 12 in sperm head shaping, nuclear DNA condensation, and early embryonic development.
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Affiliation(s)
- Ying-Hung Lin
- Graduate Institute of Basic Medical Sciences, Department of Obstetrics and Gynecology, National Cheng Kung University, College of Medicine, Tainan, Taiwan
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Lin YH, Lin YM, Kuo YC, Wang YY, Kuo PL. Identification and characterization of a novel Rab GTPase-activating protein in spermatids. ACTA ACUST UNITED AC 2010; 34:e358-67. [DOI: 10.1111/j.1365-2605.2010.01126.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Hermo L, Pelletier RM, Cyr DG, Smith CE. Surfing the wave, cycle, life history, and genes/proteins expressed by testicular germ cells. Part 5: intercellular junctions and contacts between germs cells and Sertoli cells and their regulatory interactions, testicular cholesterol, and genes/proteins associated with more than one germ cell generation. Microsc Res Tech 2010; 73:409-94. [PMID: 19941291 DOI: 10.1002/jemt.20786] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
In the testis, cell adhesion and junctional molecules permit specific interactions and intracellular communication between germ and Sertoli cells and apposed Sertoli cells. Among the many adhesion family of proteins, NCAM, nectin and nectin-like, catenins, and cadherens will be discussed, along with gap junctions between germ and Sertoli cells and the many members of the connexin family. The blood-testis barrier separates the haploid spermatids from blood borne elements. In the barrier, the intercellular junctions consist of many proteins such as occludin, tricellulin, and claudins. Changes in the expression of cell adhesion molecules are also an essential part of the mechanism that allows germ cells to move from the basal compartment of the seminiferous tubule to the adluminal compartment thus crossing the blood-testis barrier and well-defined proteins have been shown to assist in this process. Several structural components show interactions between germ cells to Sertoli cells such as the ectoplasmic specialization which are more closely related to Sertoli cells and tubulobulbar complexes that are processes of elongating spermatids embedded into Sertoli cells. Germ cells also modify several Sertoli functions and this also appears to be the case for residual bodies. Cholesterol plays a significant role during spermatogenesis and is essential for germ cell development. Lastly, we list genes/proteins that are expressed not only in any one specific generation of germ cells but across more than one generation.
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Affiliation(s)
- Louis Hermo
- Faculty of Medicine, Department of Anatomy and Cell Biology, McGill University, Montreal, Quebec, Canada H3A 2B2.
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Chao HCA, Lin YH, Kuo YC, Shen CJ, Pan HA, Kuo PL. The expression pattern of SEPT7 correlates with sperm morphology. J Assist Reprod Genet 2010; 27:299-307. [PMID: 20352323 DOI: 10.1007/s10815-010-9409-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2009] [Accepted: 03/11/2010] [Indexed: 12/11/2022] Open
Abstract
PURPOSE To investigate the expression pattern of the SEPT7 protein during spermatogenesis and its potential role in sperm function. METHODS We first investigated the expression pattern of SEPT7 during different steps of mouse spermiogenesis using an immunofluorescence assay (IFA). IFA was also applied to study the expression pattern of SEPT7 in human ejaculated spermatozoa. Nine fertile men with normal semen parameters were used as the control group, and 21 infertile men with asthenozoospermia were recruited as the patient group. We assessed the frequency of the SEPT7 signal in the various morphological subgroups. RESULTS In humans, the frequency of a defective SEPT7 signal was significantly increased in men with asthenozoospermia. The absence of a SEPT7 signal was more prevalent in sperm containing morphological defects of various types. CONCLUSIONS The expression pattern of SEPT7 suggested that this protein may be involved in the regulation of subcellular-compartment formation during spermiogenesis in the mouse. The absence of a SEPT7 signal correlated with multiple sperm defects.
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Affiliation(s)
- Hsin-Chih Albert Chao
- Division of Obstetrics and Gynecology, National Cheng Kung University College of Medicine and Hospital, Dou-Liou Branch, Yunlin, Taiwan.
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Peterson EA, Petty EM. Conquering the complex world of human septins: implications for health and disease. Clin Genet 2010; 77:511-24. [PMID: 20236126 DOI: 10.1111/j.1399-0004.2010.01392.x] [Citation(s) in RCA: 83] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Septins are highly conserved filamentous proteins first characterized in budding yeast and subsequently identified in must eukaryotes. Septins can bind and hydrolyze GTP, which is intrinsically related to their formation of septin hexamers and functional protein interactions. The human septin family is composed of 14 loci, SEPT1-SEPT14, which encode dozens of different septin proteins. Their central GTPase and polybasic domain regions are highly conserved but they diverge in their N-terminus and/or C-terminus. The mechanism by which the different isoforms are generated is not yet well understood, but one can hypothesize that the use of different promoters and/or alternative splicing could give rise to these variants. Septins perform diverse cellular functions according to tissue expression and their interacting partners. Functions identified to date include cell division, chromosome segregation, protein scaffolding, cellular polarity, motility, membrane dynamics, vesicle trafficking, exocytosis, apoptosis, and DNA damage response. Their expression is tightly regulated to maintain proper filament assembly and normal cellular functions. Alterations of these proteins, by mutation or expression changes, have been associated with a variety of cancers and neurological diseases. The association of septins with cancer results from alterations of expression in solid tumors or translocations in leukemias [mixed lineage leukemia (MLL)]. Expression changes in septins have also been associated with neurological conditions such as Alzheimer's and Parkinson's disease, as well as retinopathies, hepatitis C, spermatogenesis and Listeria infection. Pathogenic mutations of SEPT9 were identified in the autosomal dominant neurological disorder hereditary neuralgic amyotrophy (HNA). Human septin research over the past decade has established their importance in cell biology and human disease. Further functional characterization of septins is crucial to our understanding of their possible diagnostic, prognostic, and therapeutic applications.
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Affiliation(s)
- E A Peterson
- Department of Human Genetics, University of Michigan Medical School, Ann Arbor, MI, USA
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