1
|
Cheng YS, Chen HY, Lin YC, Lin YS, Yeh YC, Yeh YH, Cheng YH, Lin YM, Weng HY, Lin TY, Lin SC. The MAEL expression in mitochondria of human spermatozoa and the association with asthenozoospermia. Andrology 2023; 11:1286-1294. [PMID: 36779514 DOI: 10.1111/andr.13408] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Revised: 01/19/2023] [Accepted: 02/05/2023] [Indexed: 02/14/2023]
Abstract
PURPOSE The maelstrom spermatogenic transposon silencer (MAEL) function in postmeiotic germ cells remains unclear, and its protein localization in human testis and spermatozoa awaits determination. This study aims to clarify the MAEL expression in human spermatogenesis and to explore its role in sperm function. MATERIALS AND METHODS Twenty-seven asthenozoospermic men, 40 normozoospermic controls, and three obstructive azoospermic men were enrolled. The transcripts of MAEL in the seminiferous epithelium and MAEL downstream targets were identified by bioinformatics analysis. MAEL protein expression in human testis and ejaculated sperms were examined by immunohistochemical and immunogold staining, respectively. The roles of MAEL in mitochondria function were investigated by siRNA knockdown in human H358 cells. The association between MAEL protein levels and clinical sperm features was evaluated. RESULTS Abundant MAEL was expressed in spermatid and spermatozoa of the human testis. Remarkably, MAEL was located in the mitochondria of ejaculated sperm, and bioinformatics analysis identified GPX4 and UBL4B as MAEL's downstream targets. Knockdown of MAEL sabotaged mitochondria function and reduced adenosine triphosphate (ATP) production in H358 cells. MAEL, GPX4, and UBL4B expression levels were significantly decreased in asthenozoospermic sperms than in controls. The MAEL protein levels were positively correlated with GPX4 and UBL4B in human sperm. Total motile sperm count (TMSC) was positively correlated with protein levels of MAEL, GPX4, and UBL4B in ejaculated sperms. CONCLUSIONS We highlight prominent MAEL expression in the intratesticular spermatid and the mitochondria of ejaculated spermatozoa. MAEL directly binds to GPX4 and UBL4B, and loss of MAEL induces mitochondrial dysfunction. MAEL-mitochondrial function-motility relationship might advance our understanding of the causes of asthenozoospermia.
Collapse
Affiliation(s)
- Yu-Sheng Cheng
- Department of Urology, National Cheng Kung University Hospital, College of, Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Hsing-Yi Chen
- Department of Urology, National Cheng Kung University Hospital, College of, Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Yu-Chiao Lin
- Department of Urology, National Cheng Kung University Hospital, College of, Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Yi-Syuan Lin
- Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Yi-Chun Yeh
- International Center for Wound Repair and Regeneration, National Cheng Kung University, Tainan, Taiwan
- Department of Physiology and Pharmacology, College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Yi-Hsuan Yeh
- Department of Physiology, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Yung-Hsuan Cheng
- Department of Urology, National Cheng Kung University Hospital, College of, Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Yung-Ming Lin
- Department of Urology, National Cheng Kung University Hospital, College of, Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Han-Yu Weng
- Department of Urology, National Cheng Kung University Hospital, College of, Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Tsung-Yen Lin
- Department of Surgery, Division of Urology, National Cheng Kung University Hospital Dou-Liou Branch, Yunlin, Taiwan
| | - Shih-Chieh Lin
- Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan, Taiwan
- Department of Physiology, College of Medicine, National Cheng Kung University, Tainan, Taiwan
- Institute of Molecular Medicine, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| |
Collapse
|
2
|
Alexander AK, Rice EJ, Lujic J, Simon LE, Tanis S, Barshad G, Zhu L, Lama J, Cohen PE, Danko CG. A-MYB and BRDT-dependent RNA Polymerase II pause release orchestrates transcriptional regulation in mammalian meiosis. Nat Commun 2023; 14:1753. [PMID: 36990976 PMCID: PMC10060231 DOI: 10.1038/s41467-023-37408-w] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2022] [Accepted: 03/16/2023] [Indexed: 03/31/2023] Open
Abstract
During meiotic prophase I, spermatocytes must balance transcriptional activation with homologous recombination and chromosome synapsis, biological processes requiring extensive changes to chromatin state. We explored the interplay between chromatin accessibility and transcription through prophase I of mammalian meiosis by measuring genome-wide patterns of chromatin accessibility, nascent transcription, and processed mRNA. We find that Pol II is loaded on chromatin and maintained in a paused state early during prophase I. In later stages, paused Pol II is released in a coordinated transcriptional burst mediated by the transcription factors A-MYB and BRDT, resulting in ~3-fold increase in transcription. Transcriptional activity is temporally and spatially segregated from key steps of meiotic recombination: double strand breaks show evidence of chromatin accessibility earlier during prophase I and at distinct loci from those undergoing transcriptional activation, despite shared chromatin marks. Our findings reveal mechanisms underlying chromatin specialization in either transcription or recombination in meiotic cells.
Collapse
Affiliation(s)
- Adriana K Alexander
- Baker Institute for Animal Health, College of Veterinary Medicine, Cornell University, Ithaca, NY, 14853, USA
- Department of Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, 14853, USA
| | - Edward J Rice
- Baker Institute for Animal Health, College of Veterinary Medicine, Cornell University, Ithaca, NY, 14853, USA
| | - Jelena Lujic
- Department of Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, 14853, USA
| | - Leah E Simon
- Department of Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, 14853, USA
| | - Stephanie Tanis
- Department of Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, 14853, USA
| | - Gilad Barshad
- Baker Institute for Animal Health, College of Veterinary Medicine, Cornell University, Ithaca, NY, 14853, USA
| | - Lina Zhu
- Baker Institute for Animal Health, College of Veterinary Medicine, Cornell University, Ithaca, NY, 14853, USA
| | - Jyoti Lama
- Department of Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, 14853, USA
| | - Paula E Cohen
- Department of Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, 14853, USA.
- Cornell Reproductive Sciences Center (CoRe), Cornell University, Ithaca, NY, 14853, USA.
| | - Charles G Danko
- Baker Institute for Animal Health, College of Veterinary Medicine, Cornell University, Ithaca, NY, 14853, USA.
- Department of Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, 14853, USA.
- Cornell Reproductive Sciences Center (CoRe), Cornell University, Ithaca, NY, 14853, USA.
| |
Collapse
|
3
|
Yu C, Diao R, Khan R, Deng C, Ma H, Chang Z, Jiang X, Shi Q. The Dispensable Roles of X-Linked Ubl4a and Its Autosomal Counterpart Ubl4b in Spermatogenesis Represent a New Evolutionary Type of X-Derived Retrogenes. Front Genet 2021; 12:689902. [PMID: 34249105 PMCID: PMC8267814 DOI: 10.3389/fgene.2021.689902] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Accepted: 06/02/2021] [Indexed: 11/13/2022] Open
Abstract
X-derived retrogenes contribute to genetic diversity in evolution and are usually specifically expressed in testis and perform important functions during spermatogenesis. Ubl4b is an autosomal retrogene with testis-specific expression derived from Ubl4a, an X-linked housekeeping gene. In the current study, we performed phylogenetic analysis and revealed that Ubl4a and Ubl4b are subject to purifying selection and may have conserved functions in evolution. Ubl4b was knocked out in mice using CRISPR/Cas9 genome editing technology and interestingly, we found no alterations in reproductive parameters of Ubl4b-/- male mice. To get insights into whether Ubl4a could compensate the absence of Ubl4b in vivo, we further obtained Ubl4a-/Y; Ubl4b-/- mice that lack both Ubl4a and Ubl4b, and the double knockout (dKO) mice also displayed normal spermatogenesis, showing that Ubl4a and Ubl4b are both dispensable for spermatogenesis. Thus, through the in vivo study of UBL4A and UBL4B, we provided a direct evidence for the first time that some X chromosome-derived autosomal retrogenes can be unfunctional in spermatogenesis, which represents an additional evolutionary type of X-derived retrogenes.
Collapse
Affiliation(s)
- Changping Yu
- First Affiliated Hospital of USTC, Hefei National Laboratory for Physical Sciences at Microscale, School of Basic Medical Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China
| | - Runjie Diao
- Jiangsu Key Laboratory for Biodiversity and Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Ranjha Khan
- First Affiliated Hospital of USTC, Hefei National Laboratory for Physical Sciences at Microscale, School of Basic Medical Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China
| | - Cheng Deng
- Jiangsu Key Laboratory for Biodiversity and Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Hui Ma
- First Affiliated Hospital of USTC, Hefei National Laboratory for Physical Sciences at Microscale, School of Basic Medical Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China
| | - Zhijie Chang
- State Key Laboratory of Membrane Biology, National Engineering Laboratory for Anti-tumor Therapeutics, School of Medicine, Tsinghua University, Beijing, China
| | - Xiaohua Jiang
- First Affiliated Hospital of USTC, Hefei National Laboratory for Physical Sciences at Microscale, School of Basic Medical Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China
| | - Qinghua Shi
- First Affiliated Hospital of USTC, Hefei National Laboratory for Physical Sciences at Microscale, School of Basic Medical Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China
| |
Collapse
|
4
|
Chen J, Mortola E, Du X, Zhao S, Liu X. Excess of retrogene traffic in pig X chromosome. Genetica 2018; 147:23-32. [PMID: 30535819 DOI: 10.1007/s10709-018-0048-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Accepted: 11/21/2018] [Indexed: 11/26/2022]
Abstract
Despite the insights into retrogene evolution in multiple species provided by trans-traffic retrogenes (trans-retrogenes), cis-traffic retrogenes (cis-retrogenes) are hitherto understudied and thus limit our understanding of genetic novelty. Here we used the pig genome as a model to compare cis- and trans-retrogenes. We found that cis- and trans-retrogenes have similar patterns in terms of excessive X-chromosome representation, testis expression preference, and metabolic functional enrichment. Despite these similarities, lower levels of selective pressure were found in cis- than in trans-retrogenes. The evolutionary dating evidence revealed that more cis-retrogenes have originated after pig-cattle divergence than trans-retrogenes, suggesting a more recent origination of cis-retrogenes. The gene family clustering confirmed that excesses of X-derived cis-retrogenes may be driven by their rapid expansion in the recent times. Thus, the different selective constraints between cis- and trans-retrogenes may be due to different evolutionary time-scales rather than any differential functional importance. Thus, this study highlights the ongoing functional contributions from cis- and trans-traffic retrogenes during the reshaping of pig genome.
Collapse
Affiliation(s)
- Jianhai Chen
- Key Laboratory of Agricultural Animal Genetics, Breeding and Reproduction, Ministry of Education, College of Animal Science and Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, People's Republic of China
- Department of Ecology and Evolution, University of Chicago, Chicago, IL, USA
| | - Emily Mortola
- Department of Ecology and Evolution, University of Chicago, Chicago, IL, USA
| | - Xiaoyong Du
- Department of Ecology and Evolution, University of Chicago, Chicago, IL, USA
- College of Informatics, Huazhong Agricultural University, Wuhan, 430070, People's Republic of China
| | - Shuhong Zhao
- Key Laboratory of Agricultural Animal Genetics, Breeding and Reproduction, Ministry of Education, College of Animal Science and Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, People's Republic of China.
| | - Xiangdong Liu
- Key Laboratory of Agricultural Animal Genetics, Breeding and Reproduction, Ministry of Education, College of Animal Science and Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, People's Republic of China.
| |
Collapse
|
5
|
Kasowitz SD, Ma J, Anderson SJ, Leu NA, Xu Y, Gregory BD, Schultz RM, Wang PJ. Nuclear m6A reader YTHDC1 regulates alternative polyadenylation and splicing during mouse oocyte development. PLoS Genet 2018; 14:e1007412. [PMID: 29799838 PMCID: PMC5991768 DOI: 10.1371/journal.pgen.1007412] [Citation(s) in RCA: 353] [Impact Index Per Article: 58.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2018] [Revised: 06/07/2018] [Accepted: 05/14/2018] [Indexed: 12/31/2022] Open
Abstract
The N6-methyladenosine (m6A) modification is the most prevalent internal RNA modification in eukaryotes. The majority of m6A sites are found in the last exon and 3' UTRs. Here we show that the nuclear m6A reader YTHDC1 is essential for embryo viability and germline development in mouse. Specifically, YTHDC1 is required for spermatogonial development in males and for oocyte growth and maturation in females; Ythdc1-deficient oocytes are blocked at the primary follicle stage. Strikingly, loss of YTHDC1 leads to extensive alternative polyadenylation in oocytes, altering 3' UTR length. Furthermore, YTHDC1 deficiency causes massive alternative splicing defects in oocytes. The majority of splicing defects in mutant oocytes are rescued by introducing wild-type, but not m6A-binding-deficient, YTHDC1. YTHDC1 is associated with the pre-mRNA 3' end processing factors CPSF6, SRSF3, and SRSF7. Thus, YTHDC1 plays a critical role in processing of pre-mRNA transcripts in the oocyte nucleus and may have similar non-redundant roles throughout fetal development.
Collapse
Affiliation(s)
- Seth D. Kasowitz
- Department of Biomedical Sciences, University of Pennsylvania, Philadelphia, United States of America
| | - Jun Ma
- Department of Biomedical Sciences, University of Pennsylvania, Philadelphia, United States of America
- Department of Biology, University of Pennsylvania, Philadelphia, United States of America
| | - Stephen J. Anderson
- Department of Biology, University of Pennsylvania, Philadelphia, United States of America
| | - N. Adrian Leu
- Department of Biomedical Sciences, University of Pennsylvania, Philadelphia, United States of America
| | - Yang Xu
- Department of Biomedical Sciences, University of Pennsylvania, Philadelphia, United States of America
| | - Brian D. Gregory
- Department of Biology, University of Pennsylvania, Philadelphia, United States of America
| | - Richard M. Schultz
- Department of Biology, University of Pennsylvania, Philadelphia, United States of America
- Department of Anatomy, Physiology and Cell Biology, School of Veterinary Medicine, University of California, Davis, Davis, United States of America
| | - P. Jeremy Wang
- Department of Biomedical Sciences, University of Pennsylvania, Philadelphia, United States of America
| |
Collapse
|
6
|
Liang J, Li J, Fu Y, Ren F, Xu J, Zhou M, Li P, Feng H, Wang Y. GdX/UBL4A null mice exhibit mild kyphosis and scoliosis accompanied by dysregulation of osteoblastogenesis and chondrogenesis. Cell Biochem Funct 2018; 36:129-136. [DOI: 10.1002/cbf.3324] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2017] [Accepted: 12/27/2017] [Indexed: 11/08/2022]
Affiliation(s)
- Jiao Liang
- State Key Laboratory of Membrane Biology, School of Medicine; Tsinghua University; Beijing China
| | - Jun Li
- State Key Laboratory of Membrane Biology, School of Medicine; Tsinghua University; Beijing China
| | - Yanxia Fu
- State Key Laboratory of Membrane Biology, School of Medicine; Tsinghua University; Beijing China
- Tsinghua University-Perking University Joint Center for Life Sciences; Beijing China
| | - Fangli Ren
- State Key Laboratory of Membrane Biology, School of Medicine; Tsinghua University; Beijing China
| | - Jiake Xu
- School of Biomedical Sciences; University of Western Australia; Perth Western Australia Australia
| | - Mengyu Zhou
- Department of Dentistry; The First Affiliated Hospital of Guangxi Medical University; Nanning China
| | - Peiyu Li
- The General Hospital of the People's Liberation Army; Beijing China
| | - Haotian Feng
- Research Centre for Regenerative Medicine; Guangxi Medical University; Nanning China
| | - Yinyin Wang
- State Key Laboratory of Membrane Biology, School of Medicine; Tsinghua University; Beijing China
| |
Collapse
|
7
|
Moretti C, Vaiman D, Tores F, Cocquet J. Expression and epigenomic landscape of the sex chromosomes in mouse post-meiotic male germ cells. Epigenetics Chromatin 2016; 9:47. [PMID: 27795737 PMCID: PMC5081929 DOI: 10.1186/s13072-016-0099-8] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2016] [Accepted: 10/17/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND During meiosis, the X and Y chromosomes are transcriptionally silenced. The persistence of repressive chromatin marks on the sex chromatin after meiosis initially led to the assumption that XY gene silencing persists to some extent in spermatids. Considering the many reports of XY-linked genes expressed and needed in the post-meiotic phase of mouse spermatogenesis, it is still unclear whether or not the mouse sex chromatin is a repressive or permissive environment, after meiosis. RESULTS To determine the transcriptional and chromatin state of the sex chromosomes after meiosis, we re-analyzed ten ChIP-Seq datasets performed on mouse round spermatids and four RNA-seq datasets from male germ cells purified at different stages of spermatogenesis. For this, we used the last version of the genome (mm10/GRCm38) and included reads that map to several genomic locations in order to properly interpret the high proportion of sex chromosome-encoded multicopy genes. Our study shows that coverage of active epigenetic marks H3K4me3 and Kcr is similar on the sex chromosomes and on autosomes. The post-meiotic sex chromatin nevertheless differs from autosomal chromatin in its enrichment in H3K9me3 and its depletion in H3K27me3 and H4 acetylation. We also identified a posttranslational modification, H3K27ac, which specifically accumulates on the Y chromosome. In parallel, we found that the X and Y chromosomes are enriched in genes expressed post-meiotically and display a higher proportion of spermatid-specific genes compared to autosomes. Finally, we observed that portions of chromosome 14 and of the sex chromosomes share specific features, such as enrichment in H3K9me3 and the presence of multicopy genes that are specifically expressed in round spermatids, suggesting that parts of chromosome 14 are under the same evolutionary constraints than the sex chromosomes. CONCLUSIONS Based on our expression and epigenomic studies, we conclude that, after meiosis, the mouse sex chromosomes are no longer silenced but are nevertheless regulated differently than autosomes and accumulate different chromatin marks. We propose that post-meiotic selective constraints are at the basis of the enrichment of spermatid-specific genes and of the peculiar chromatin composition of the sex chromosomes and of parts of chromosome 14.
Collapse
Affiliation(s)
- Charlotte Moretti
- Institut National de la Sante et de la Recherche Medicale (INSERM) U1016, Institut Cochin, Paris, France ; Centre National de la Recherche Scientifique (CNRS), UMR8104, Paris, France ; Faculté de Médecine, Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Daniel Vaiman
- Institut National de la Sante et de la Recherche Medicale (INSERM) U1016, Institut Cochin, Paris, France ; Centre National de la Recherche Scientifique (CNRS), UMR8104, Paris, France ; Faculté de Médecine, Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Frederic Tores
- INSERM U1163, Université Paris Descartes, Sorbonne Paris Cité, Institut Imagine, 24 Boulevard du Montparnasse, 75015 Paris, France
| | - Julie Cocquet
- Institut National de la Sante et de la Recherche Medicale (INSERM) U1016, Institut Cochin, Paris, France ; Centre National de la Recherche Scientifique (CNRS), UMR8104, Paris, France ; Faculté de Médecine, Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| |
Collapse
|
8
|
Hofmeister-Brix A, Kollmann K, Langer S, Schultz J, Lenzen S, Baltrusch S. Identification of the ubiquitin-like domain of midnolin as a new glucokinase interaction partner. J Biol Chem 2013; 288:35824-39. [PMID: 24187134 DOI: 10.1074/jbc.m113.526632] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Glucokinase acts as a glucose sensor in pancreatic beta cells. Its posttranslational regulation is important but not yet fully understood. Therefore, a pancreatic islet yeast two-hybrid library was produced and searched for glucokinase-binding proteins. A protein sequence containing a full-length ubiquitin-like domain was identified to interact with glucokinase. Mammalian two-hybrid and fluorescence resonance energy transfer analyses confirmed the interaction between glucokinase and the ubiquitin-like domain in insulin-secreting MIN6 cells and revealed the highest binding affinity at low glucose. Overexpression of parkin, an ubiquitin E3 ligase exhibiting an ubiquitin-like domain with high homology to the identified, diminished insulin secretion in MIN6 cells but had only some effect on glucokinase activity. Overexpression of the elucidated ubiquitin-like domain or midnolin, containing exactly this ubiquitin-like domain, significantly reduced both intrinsic glucokinase activity and glucose-induced insulin secretion. Midnolin has been to date classified as a nucleolar protein regulating mouse development. However, we could not confirm localization of midnolin in nucleoli. Fluorescence microscopy analyses revealed localization of midnolin in nucleus and cytoplasm and co-localization with glucokinase in pancreatic beta cells. In addition we could show that midnolin gene expression in pancreatic islets is up-regulated at low glucose and that the midnolin protein is highly expressed in pancreatic beta cells and also in liver, muscle, and brain of the adult mouse and cell lines of human and rat origin. Thus, the results of our study suggest that midnolin plays a role in cellular signaling of adult tissues and regulates glucokinase enzyme activity in pancreatic beta cells.
Collapse
Affiliation(s)
- Anke Hofmeister-Brix
- From the Institute of Clinical Biochemistry, Hannover Medical School, 30625 Hannover, Germany and
| | | | | | | | | | | |
Collapse
|
9
|
Structures of the Sgt2/SGTA dimerization domain with the Get5/UBL4A UBL domain reveal an interaction that forms a conserved dynamic interface. Cell Rep 2012; 2:1620-32. [PMID: 23142665 DOI: 10.1016/j.celrep.2012.10.010] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2012] [Revised: 09/25/2012] [Accepted: 10/08/2012] [Indexed: 10/27/2022] Open
Abstract
In the cytoplasm, the correct delivery of membrane proteins is an essential and highly regulated process. The posttranslational targeting of the important tail-anchor membrane (TA) proteins has recently been under intense investigation. A specialized pathway, called the guided entry of TA proteins (GET) pathway in yeast and the transmembrane domain recognition complex (TRC) pathway in vertebrates, recognizes endoplasmic-reticulum-targeted TA proteins and delivers them through a complex series of handoffs. An early step is the formation of a complex between Sgt2/SGTA, a cochaperone with a presumed ubiquitin-like-binding domain (UBD), and Get5/UBL4A, a ubiquitin-like domain (UBL)-containing protein. We structurally characterize this UBD/UBL interaction for both yeast and human proteins. This characterization is supported by biophysical studies that demonstrate that complex formation is mediated by electrostatics, generating an interface that has high-affinity with rapid kinetics. In total, this work provides a refined model of the interplay of Sgt2 homologs in TA targeting.
Collapse
|
10
|
Kato Y, Nozaki M. Distinct DNA methylation dynamics of spermatogenic cell-specific intronless genes is associated with CpG content. PLoS One 2012; 7:e43658. [PMID: 22952732 PMCID: PMC3428356 DOI: 10.1371/journal.pone.0043658] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2012] [Accepted: 07/23/2012] [Indexed: 11/24/2022] Open
Abstract
In mammals, DNA methylation is restricted to cytosines of CpG dinucleotides, which are frequently found in short genomic regions including gene promoters. Methylation within CpG-rich regions around promoters tends to repress gene expression; thus, the CpG islands of housekeeping genes are normally unmethylated. We previously described a testis-specific single-exon gene containing a CpG-rich sequence that is methylated and thus repressed in somatic cells, whereas its expression in spermatogenic cells requires that it be hypomethylated. However, the relationship among the specific expression of spermatogenic genes, their methylation dynamics, and their CpG frequencies are poorly understood. Here, we analyzed the methylation patterns of the sphort genomic region around the transcription start site in spermatogenic cell-specific single-exon genes of various CpG contents. By using UniGene and Ensembl database analyses of the mouse genome and reverse transcription-PCR, we identified 39 single-exon genes that are exclusively expressed in spermatogeniccells. Regardless of their specific expression characteristics, genes containing higher (7 to 14 CpGs in 200 bp; mean = 12) and lower (2 to 6 CpGs in 200 bp; mean = 3.1) number ofCpG were hypo- and hyper-methylated, respectively, in all cell types examined, including spermatogeniccells. We found that genes with intermediate number of CpG (2 to 11 CpGs in 200 bp; mean = 6.9) are methylated in somatic cells, but not in male germ cells. These results suggest that DNA methylation dynamics of spermatogenic cell-specific single-exon genes are associated with CpG content, and the methylation status are stably maintained throughout male germ cell development.
Collapse
Affiliation(s)
- Yuzuru Kato
- Department of Cell Biology, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka, Japan
| | - Masami Nozaki
- Department of Cell Biology, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka, Japan
- * E-mail:
| |
Collapse
|
11
|
Wang Y, Wang D, Ren F, Zhang Y, Lin F, Hou N, Cheng X, Zhang P, Wang Y, Jia B, Yang X, Chang Z. Generation of mice with conditional null allele for GdX/Ubl4A. Genesis 2012; 50:534-42. [PMID: 22139977 DOI: 10.1002/dvg.20832] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2011] [Revised: 10/26/2011] [Accepted: 11/23/2011] [Indexed: 11/12/2022]
Abstract
GdX (also named Ubl4A) is a house-keeping gene located on the X chromosome and encodes a protein harboring an ubiquitin-like domain in human and mouse. Although identified in 1988, the function of GdX remains unknown. To elucidate the role of GdX in vivo, we generated a conditional GdX knockout mouse in which Exon 2 was flanked by two loxP sites. We obtained viable and fertile mice with homozygous GdX(flox/flox) or GdX(flox/Y) allele. Germ-line transmission was confirmed by crossing the mouse bearing conditionally targeted allele with an EIIα-Cre transgenic mouse. GdX was successfully depleted in tissues of EIIα-Cre-GdX-null mice. GdX(-/-) and GdX(-/Y) mice are viable and exhibit normal development compared with wild-type littermates within 6 months during our observation. We also observed that GdX knockout male mice were functionally normal in the reproductive system where Ubl4B was specifically expressed. GdX(flox/flox) and GdX(flox/Y) conditional mice provide a tool for further tissue-specific function analysis of the GdX protein under different conditions.
Collapse
Affiliation(s)
- Yangmeng Wang
- State Key Laboratory of Biomembrane and Membrane Biotechnology, School of Medicine, Tsinghua University, Beijing, China
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
12
|
Zhou J, Pan J, Eckardt S, Leu NA, McLaughlin KJ, Wang PJ. Nxf3 is expressed in Sertoli cells, but is dispensable for spermatogenesis. Mol Reprod Dev 2011; 78:241-9. [PMID: 21308854 DOI: 10.1002/mrd.21291] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2010] [Accepted: 01/17/2011] [Indexed: 02/03/2023]
Abstract
In eukaryotes, mRNA is actively exported to the cytoplasm by a family of nuclear RNA export factors (NXF). Four Nxf genes have been identified in the mouse: Nxf1, Nxf2, Nxf3, and Nxf7. Inactivation of Nxf2, a germ cell-specific gene, causes defects in spermatogenesis. Here we report that Nxf3 is expressed exclusively in Sertoli cells of the postnatal testis, in a developmentally regulated manner. Expression of Nxf3 coincides with the cessation of Sertoli cell proliferation and the beginning of their differentiation. Continued expression of Nxf3 in mature Sertoli cells of the adult is spermatogenesis stage-independent. Nxf3 is not essential for spermatogenesis, however, suggesting functional redundancy among Nxf family members. With its unique expression pattern in the testis, the promoter of Nxf3 can be used to drive postnatal Sertoli cell-specific expression of other proteins such as Cre recombinase.
Collapse
Affiliation(s)
- Jian Zhou
- Department of Animal Biology, Center for Animal Transgenesis and Germ Cell Research, University of Pennsylvania School of Veterinary Medicine, Philadelphia, Pennsylvania 19104, USA
| | | | | | | | | | | |
Collapse
|
13
|
Rohozinski J, Anderson ML, Broaddus RE, Edwards CL, Bishop CE. Spermatogenesis associated retrogenes are expressed in the human ovary and ovarian cancers. PLoS One 2009; 4:e5064. [PMID: 19333399 PMCID: PMC2660244 DOI: 10.1371/journal.pone.0005064] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2008] [Accepted: 02/06/2009] [Indexed: 12/24/2022] Open
Abstract
Background Ovarian cancer is the second most prevalent gynecologic cancer in women. However, it is by far the most lethal. This is generally attributed to the absence of easily detectable markers specific to ovarian cancers that can be used for early diagnosis and specific therapeutic targets. Methodology/Principal Findings Using end point PCR we have found that a family of retrogenes, previously thought to be expressed only in the male testis during spermatogenesis in man, are also expressed in normal ovarian tissue and a large percentage of ovarian cancers. In man there are at least eleven such autosomal retrogenes, which are intronless copies of genes on the X chromosome, essential for normal spermatogenesis and expressed specifically in the human testis. We tested for the expression of five of the known retrogenes, UTP14C, PGK2, RPL10L, RPL39L and UBL4B in normal human ovary and ovarian cancers. Conclusions/Significance We propose that the activation of the testis specific retrogenes in the ovary and ovarian cancers is of biological significance in humans. Because these retrogenes are specifically expressed in the ovary and ovarian cancers in the female they may prove useful in developing new diagnostic and/or therapeutic targets for ovarian cancer.
Collapse
Affiliation(s)
- Jan Rohozinski
- Department of Obstetrics and Gynecology, Baylor College of Medicine, Houston, TX, USA.
| | | | | | | | | |
Collapse
|
14
|
Wojtczak A, Kwiatkowska M. Immunocytochemical and Ultrastructural Analyses of the Function of the Ubiquitin-Proteasome System During Spermiogenesis with the Use of the Inhibitors of Proteasome Proteolytic Activity in the Alga, Chara vulgaris1. Biol Reprod 2008; 78:577-85. [DOI: 10.1095/biolreprod.107.062901] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
|
15
|
Wang PJ, Pan J. The role of spermatogonially expressed germ cell-specific genes in mammalian meiosis. Chromosome Res 2007; 15:623-32. [PMID: 17674150 DOI: 10.1007/s10577-007-1141-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Meiosis, a hallmark of sexual reproduction, reduces the chromatin complement by half to cope with genome doubling at fertilization and permits exchange of genetic material between parental genomes. Recent functional studies of novel proteins have greatly enhanced our understanding of the regulation of meiosis. The unique status of sex chromosomes in the male germ line may have shaped their content of germ line-intrinsic genes during evolution. Previously, a unique set of 36 spermatogonially expressed, mouse germ cell-specific genes was identified in one genomic screen. Thirteen of these genes have been disrupted in mice and two-thirds of these mouse mutants exhibit meiotic defects. Therefore, we hypothesize that the majority of uncharacterized germ cell-specific genes identified in the same screen, including 11 X-linked genes, might also play important roles in meiosis. In particular, we cite previously unpublished studies demonstrating that the NXF2 protein, an X-encoded factor, is present in early spermatocytes.
Collapse
Affiliation(s)
- P Jeremy Wang
- Department of Animal Biology, School of Veterinary Medicine, University of Pennsylvania, 3800 Spruce Street, Philadelphia, PA 19104, USA.
| | | |
Collapse
|
16
|
Cheng Y, Buffone MG, Kouadio M, Goodheart M, Page DC, Gerton GL, Davidson I, Wang PJ. Abnormal sperm in mice lacking the Taf7l gene. Mol Cell Biol 2007; 27:2582-9. [PMID: 17242199 PMCID: PMC1899882 DOI: 10.1128/mcb.01722-06] [Citation(s) in RCA: 89] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
TFIID is a general transcription factor required for transcription of most protein-coding genes by RNA polymerase II. TAF7L is an X-linked germ cell-specific paralogue of TAF7, which is a generally expressed component of TFIID. Here, we report the generation of Taf7l mutant mice by homologous recombination in embryonic stem cells by using the Cre-loxP strategy. While spermatogenesis was completed in Taf7l(-/Y) mice, the weight of Taf7l(-/Y) testis decreased and the amount of sperm in the epididymides was sharply reduced. Mutant epididymal sperm exhibited abnormal morphology, including folded tails. Sperm motility was significantly reduced, and Taf7l(-/Y) males were fertile with reduced litter size. Microarray profiling revealed that the abundance of six gene transcripts (including Fscn1) in Taf7l(-/Y) testes decreased more than twofold. In particular, FSCN1 is an F-action-bundling protein and thus may be critical for normal sperm morphology and sperm motility. Although deficiency of Taf7l may be compensated in part by Taf7, Taf7l has apparently evolved new specialized functions in the gene-selective transcription in male germ cell differentiation. Our mouse studies suggest that mutations in the human TAF7L gene might be implicated in X-linked oligozoospermia in men.
Collapse
Affiliation(s)
- Yong Cheng
- Department of Animal Biology, School of Veterinary Medicine, University of Pennsylvania, 3800 Spruce Street, Philadelphia, PA 19104, USA
| | | | | | | | | | | | | | | |
Collapse
|