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Shen W, Chen Y, Yao H, Du C, Luan N, Yan X. A novel defensin-like antimicrobial peptide from the skin secretions of the tree frog, Theloderma kwangsiensis. Gene 2016; 576:136-40. [DOI: 10.1016/j.gene.2015.09.086] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2015] [Revised: 09/17/2015] [Accepted: 09/30/2015] [Indexed: 10/22/2022]
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2
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The first anionic defensin from amphibians. Amino Acids 2015; 47:1301-8. [DOI: 10.1007/s00726-015-1963-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2014] [Accepted: 03/10/2015] [Indexed: 12/30/2022]
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3
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Ribeiro CM, Queiróz DBC, Patrão MTCC, Denadai-Souza A, Romano RM, Silva EJR, Avellar MCW. Dynamic changes in the spatio-temporal expression of the β-defensin SPAG11C in the developing rat epididymis and its regulation by androgens. Mol Cell Endocrinol 2015; 404:141-50. [PMID: 25657045 DOI: 10.1016/j.mce.2015.01.013] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/05/2014] [Revised: 01/02/2015] [Accepted: 01/08/2015] [Indexed: 11/24/2022]
Abstract
Herein, we characterized the spatio-temporal expression, cellular distribution and regulation by androgens of the β-defensin SPAG11C, the rat ortholog of the human SPAG11B isoform C, in the developing epididymis by using RT-PCR, in situ hybridization and immunohistochemistry. We observed that Spag11c mRNA was ubiquitously expressed in rat fetuses, but preferentially detected in male reproductive tissues at adulthood. SPAG11C (mRNA and protein) was prenatally mainly detected in the mesenchyme of the Wolffian duct, switching gradually after birth to a predominant localization in the epididymis epithelium during postnatal development. In the adult epididymis, smooth muscle and interstitial cells were also identified as sources of SPAG11C. Furthermore, SPAG11C was differentially immunolocalized on spermatozoa surface during their transit from testis throughout caput and cauda epididymis. Developmental and surgical castration studies suggested that androgens contribute to the epididymal cell type- and region-specific modulation of SPAG11C mRNA levels and immunolocalization. Together our findings provide novel insights into the potential role of β-defensins in the epididymis.
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Affiliation(s)
- Camilla M Ribeiro
- Section of Experimental Endocrinology, Department of Pharmacology, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, SP 04044-020, Brazil
| | - Daniel B C Queiróz
- Section of Experimental Endocrinology, Department of Pharmacology, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, SP 04044-020, Brazil
| | - Marília T C C Patrão
- Section of Experimental Endocrinology, Department of Pharmacology, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, SP 04044-020, Brazil
| | - Alexandre Denadai-Souza
- Section of Experimental Endocrinology, Department of Pharmacology, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, SP 04044-020, Brazil
| | - Renata M Romano
- Section of Experimental Endocrinology, Department of Pharmacology, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, SP 04044-020, Brazil
| | - Erick J R Silva
- Section of Experimental Endocrinology, Department of Pharmacology, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, SP 04044-020, Brazil
| | - Maria Christina W Avellar
- Section of Experimental Endocrinology, Department of Pharmacology, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, SP 04044-020, Brazil.
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4
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Abstract
Antimicrobial proteins and peptides are ubiquitous in nature with diverse structural and biological properties. Among them, the human beta-defensins are known to contribute to the innate immune response. Besides the defensins, a number of defensin-like proteins and peptides are expressed in many organ systems including the male reproductive system. Some of the protein isoforms encoded by the sperm associated antigen 11B (SPAG11) gene in humans are beta-defensin-like and exhibit structure dependent and salt tolerant antimicrobial activity, besides contributing to sperm maturation. Though some of the functional roles of these proteins are reported, the structural and molecular features that contribute to their antimicrobial activity is not yet reported. In this study, using in silico tools, we report the three dimensional structure of the human SPAG11B proteins and their C-terminal peptides. web-based hydropathy, amphipathicity, and topology (WHAT) analyses and grand average of hydropathy (GRAVY) indices show that these proteins and peptides are amphipathic and highly hydrophilic. Self-optimized prediction method with alignment (SOPMA) analyses and circular dichroism data suggest that the secondary structure of these proteins and peptides primarily contain beta-sheet and random coil structure and alpha-helix to a lesser extent. Ramachandran plots show that majority of the amino acids in these proteins and peptides fall in the permissible regions, thus indicating stable structures. The secondary structure of SPAG11B isoforms and their peptides were not perturbed with increasing NaCl concentration (0-300 mM) and at different pH (3, 7, and 10), thus reinforcing our previously reported observation that their antimicrobial activity is salt tolerant. To the best of our knowledge, for the first time, results of our study provide vital information on the structural features of SPAG11B protein isoforms and their contribution to antimicrobial activity.
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Affiliation(s)
- Ganapathy Narmadha
- Department of Animal Biology, University of Hyderabad , Andhra Pradesh , India
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5
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Ottolini B, Hornsby MJ, Abujaber R, MacArthur JAL, Badge RM, Schwarzacher T, Albertson DG, Bevins CL, Solnick JV, Hollox EJ. Evidence of convergent evolution in humans and macaques supports an adaptive role for copy number variation of the β-defensin-2 gene. Genome Biol Evol 2014; 6:3025-38. [PMID: 25349268 PMCID: PMC4255768 DOI: 10.1093/gbe/evu236] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
β-defensins are a family of important peptides of innate immunity, involved in host defense, immunomodulation, reproduction, and pigmentation. Genes encoding β-defensins show evidence of birth-and-death evolution, adaptation by amino acid sequence changes, and extensive copy number variation (CNV) within humans and other species. The role of CNV in the adaptation of β-defensins to new functions remains unclear, as does the adaptive role of CNV in general. Here, we fine-map CNV of a cluster of β-defensins in humans and rhesus macaques. Remarkably, we found that the structure of the CNV is different between primates, with distinct mutational origins and CNV boundaries defined by retroviral long terminal repeat elements. Although the human β-defensin CNV region is 322 kb and encompasses several genes, including β-defensins, a long noncoding RNA gene, and testes-specific zinc-finger transcription factors, the orthologous region in the rhesus macaque shows CNV of a 20-kb region, containing only a single gene, the ortholog of the human β-defensin-2 gene. Despite its independent origins, the range of gene copy numbers in the rhesus macaque is similar to humans. In addition, the rhesus macaque gene has been subject to divergent positive selection at the amino acid level following its initial duplication event between 3 and 9.5 Ma, suggesting adaptation of this gene as the macaque successfully colonized novel environments outside Africa. Therefore, the molecular phenotype of β-defensin-2 CNV has undergone convergent evolution, and this gene shows evidence of adaptation at the amino acid level in rhesus macaques.
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Affiliation(s)
| | - Michael J Hornsby
- Department of Microbiology and Immunology, University of California Davis School of Medicine
| | - Razan Abujaber
- Department of Genetics, University of Leicester, United Kingdom
| | - Jacqueline A L MacArthur
- Helen Diller Family Comprehensive Cancer Center, University of California San Francisco Present address: European Molecular Biology Laboratory, European Bioinformatics Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, United Kingdom
| | - Richard M Badge
- Department of Genetics, University of Leicester, United Kingdom
| | | | - Donna G Albertson
- Helen Diller Family Comprehensive Cancer Center, University of California San Francisco Present address: Bluestone Center for Clinical Research, New York University College of Dentistry, New York, New York
| | - Charles L Bevins
- Department of Microbiology and Immunology, University of California Davis School of Medicine
| | - Jay V Solnick
- Department of Microbiology and Immunology, University of California Davis School of Medicine Department of Medicine, Center for Comparative Medicine, and the California National Primate Research Center, University of California
| | - Edward J Hollox
- Department of Genetics, University of Leicester, United Kingdom
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6
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Guyonnet B, Marot G, Dacheux JL, Mercat MJ, Schwob S, Jaffrézic F, Gatti JL. The adult boar testicular and epididymal transcriptomes. BMC Genomics 2009; 10:369. [PMID: 19664223 PMCID: PMC2738690 DOI: 10.1186/1471-2164-10-369] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2009] [Accepted: 08/07/2009] [Indexed: 12/30/2022] Open
Abstract
Background Mammalians gamete production takes place in the testis but when they exit this organ, although spermatozoa have acquired a specialized and distinct morphology, they are immotile and infertile. It is only after their travel in the epididymis that sperm gain their motility and fertility. Epididymis is a crescent shaped organ adjacent to the testis that can be divided in three gross morphological regions, head (caput), body (corpus) and tail (cauda). It contains a long and unique convoluted tubule connected to the testis via the efferent ducts and finished by joining the vas deferens in its caudal part. Results In this study, the testis, the efferent ducts (vas efferens, VE), nine distinct successive epididymal segments and the deferent duct (vas deferens, VD) of four adult boars of known fertility were isolated and their mRNA extracted. The gene expression of each of these samples was analyzed using a pig generic 9 K nylon microarray (AGENAE program; GEO accession number: GPL3729) spotted with 8931 clones derived from normalized cDNA banks from different pig tissues including testis and epididymis. Differentially expressed transcripts were obtained with moderated t-tests and F-tests and two data clustering algorithms based either on partitioning around medoid (top down PAM) or hierarchical clustering (bottom up HCL) were combined for class discovery and gene expression analysis. Tissue clustering defined seven transcriptomic units: testis, vas efferens and five epididymal transcriptomic units. Meanwhile transcripts formed only four clusters related to the tissues. We have then used a specific statistical method to sort out genes specifically over-expressed (markers) in testis, VE or in each of the five transcriptomic units of the epididymis (including VD). The specific regional expression of some of these genes was further validated by PCR and Q-PCR. We also searched for specific pathways and functions using available gene ontology information. Conclusion This study described for the first time the complete transcriptomes of the testis, the epididymis, the vas efferens and the vas deferens on the same species. It described new genes or genes not yet reported over-expressed in these boar tissues, as well as new control mechanisms. It emphasizes and fulfilled the gap between studies done in rodents and human, and provides tools that will be useful for further studies on the biochemical processes responsible for the formation and maintain of the epididymal regionalization and the development of a fertile spermatozoa.
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Affiliation(s)
- Benoît Guyonnet
- UMR85 Physiologie de Reproduction et des Comportements, Institut National de Recherche Agronomique, F-37380 Nouzilly, France.
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Radhakrishnan Y, Hamil KG, Tan JA, Grossman G, Petrusz P, Hall SH, French FS. Novel partners of SPAG11B isoform D in the human male reproductive tract. Biol Reprod 2009; 81:647-56. [PMID: 19535787 DOI: 10.1095/biolreprod.109.077545] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Human sperm-associated antigen 11 (SPAG11) is closely related to beta-defensins in structure, expression, and function. Like the beta-defensins, SPAG11 proteins are predominantly expressed in the male reproductive tract, where their best-known major roles are in innate host defense and reproduction. Although several hypotheses have emerged to describe the evolution of beta-defensin and SPAG11 multifunctionality, few describe these multiple functions in terms of defensin interactions with specific proteins. To gain insight into the protein interaction potentials of SPAG11 and the signaling pathways that SPAG11 may influence, we used a yeast two-hybrid screening of a human testis-epididymis library. The results reveal human SPAG11B isoform D (SPAG11B/D) interactions with tryptase alpha/beta 1 (TPSAB1), tetraspanin 7 (TSPAN7), and attractin (ATRN). These interactions were confirmed by coimmunoprecipitation and glutathione S-transferase affinity matrix binding. SPAG11B/D and the three interacting proteins are expressed in the proximal epididymis, and all function in immunity and fertility pathways. We analyzed the functional consequences of SPAG11B/D interaction with TPSAB1 and showed that SPAG11B/D is both a substrate and a potent inhibitor of TPSAB1 activity. Furthermore, we show that (like SPAG11B/D) TSPAN7 and ATRN are associated with spermatozoa.
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Affiliation(s)
- Yashwanth Radhakrishnan
- Departments of Pediatrics and Cell and Developmental Biology, Laboratories for Reproductive Biology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA.
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8
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Insertion mode of a novel anionic antimicrobial peptide MDpep5 (Val-Glu-Ser-Trp-Val) from Chinese traditional edible larvae of housefly and its effect on surface potential of bacterial membrane. J Pharm Biomed Anal 2008; 48:1187-94. [DOI: 10.1016/j.jpba.2008.09.006] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2008] [Accepted: 09/01/2008] [Indexed: 11/18/2022]
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9
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Palladino MA, Savarese MA, Chapman JL, Dughi MK, Plaska D. ORIGINAL ARTICLE: Localization of Toll-Like Receptors on Epididymal Epithelial Cells and Spermatozoa. Am J Reprod Immunol 2008; 60:541-55. [DOI: 10.1111/j.1600-0897.2008.00654.x] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
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10
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Recombinant proprotein convertase 4 (PC4) from Leishmania tarentolae expression system: Purification, biochemical study and inhibitor design. Protein Expr Purif 2008; 60:117-26. [DOI: 10.1016/j.pep.2008.03.013] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2007] [Revised: 03/12/2008] [Accepted: 03/19/2008] [Indexed: 11/18/2022]
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11
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Avellar MCW, Honda L, Hamil KG, Radhakrishnan Y, Yenugu S, Grossman G, Petrusz P, French FS, Hall SH. Novel aspects of the sperm-associated antigen 11 (SPAG11) gene organization and expression in cattle (Bos taurus). Biol Reprod 2007; 76:1103-16. [PMID: 17344469 DOI: 10.1095/biolreprod.106.059626] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
Beta-defensins are small cationic peptides exhibiting broad spectrum antimicrobial properties. In humans, many beta-defensin genes are located within a cluster on chromosome 8p23. The sperm associated antigen 11 (SPAG11) gene is contained in this cluster and is unusual among the human beta-defensins due to its complex genomic structure and mRNA splicing pattern. Here we report the genomic organization of the Bos taurus SPAG11 gene located on chromosome 27q1.2, within a cluster of beta-defensin genes. The exon structures of the fused bovine SPAG11 gene and of the mosaic transcripts initiated at both A and B promoters were established, including identification of novel exons and transcripts not previously found in primate or rodent. Evolutionary analysis against primate, rodent, canine, and porcine orthologs was performed. In adult bulls SPAG11C, SPAG11E, and SPAG11U mRNAs were detected predominantly in the male reproductive tract, while SPAG11D transcript was detected in reproductive and nonreproductive tissues and SPAG11V and SPAG11W mRNAs were confined to testis. Differential expression of all six transcripts was observed in tissues from fetal and adult bulls, suggesting that similar mRNA splicing mechanisms govern SPAG11 gene expression during pre- and postnatal development. Immunolocalization of SPAG11C and SPAG11D/E was demonstrated in the epithelium of the epididymis and testis, and SPAG11D in association with epididymal spermatozoa. Recombinant full-length SPAG11D protein was strongly antibacterial, while the SPAG11E C-terminal peptide that contains the beta-defensin motif in its structure was somewhat less potent. Taken together, the results suggest that SPAG11 isoforms perform both immune and reproductive functions in cattle.
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Affiliation(s)
- Maria Christina W Avellar
- Section of Experimental Endocrinology, Department of Pharmacology, Universidade Federal de São Paulo-Escola Paulista de Medicina, Rua 03 de Maio 100, Vila Clementino, São Paulo (SP) 04044-020, Brazil.
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12
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Semple CA, Gautier P, Taylor K, Dorin JR. The changing of the guard: Molecular diversity and rapid evolution of beta-defensins. Mol Divers 2007; 10:575-84. [PMID: 16969721 DOI: 10.1007/s11030-006-9031-7] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Defensins are small cationic peptides involved in innate immunity and are components of the first line of defence against invading pathogens. beta-defensins are a subgroup of the defensin family that display a particular cysteine spacing and pattern of intramolecular bonding. These molecules are produced mostly by epithelia lining exposed surfaces and appear to have both antimicrobial and cell signalling functions. The unusually high degree of sequence variation in the mature peptide produced by the paralogous and in some cases orthologous genes implies extensive specialisation and species specific adaptation. Here we review recent functional data that are an important addition to our knowledge of the innate immune response and novel antibiotic design. We also consider the organisation and evolution of the genomic loci harbouring these genes where radical and rapid changes in beta-defensin sequences have been shown to result from the interplay of both positive and negative selection. Consequently these genes provide some unusually clear glimpses of the processes of duplication and specialisation that have shaped the mammalian genome.
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Affiliation(s)
- Colin A Semple
- MRC Human Genetics Unit, Western General Hospital, Crewe Road, Edinburgh, UK
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Palladino MA, Johnson TA, Gupta R, Chapman JL, Ojha P. Members of the Toll-like receptor family of innate immunity pattern-recognition receptors are abundant in the male rat reproductive tract. Biol Reprod 2007; 76:958-64. [PMID: 17314314 DOI: 10.1095/biolreprod.106.059410] [Citation(s) in RCA: 94] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
Protecting developing and maturing spermatozoa and reproductive tissues from microbial damage is an emerging aspect of research in reproductive physiology. Bacterial, viral, and yeast infections of the testis and epididymis can hinder maturation and movement of spermatozoa, resulting in impaired fertility. Toll-like receptors (TLRs) are a broad family of innate immunity receptors that play critical roles in detecting and responding to invading pathogens. Objectives of this study were to determine if organs of the rat male reproductive tract express mRNAs for members of the TLR family, to characterize expression patterns for TLRs in different regions of the epididymis, and to determine if TLR adaptor and target proteins are present in the male reproductive tract. Messenger RNA for Tlr1-Tlr9 was abundantly expressed in testis, epididymis, and vas deferens, as determined by RT-PCR, while Tlr10 and Tlr11 were less abundantly expressed. Tlr mRNA expression showed no region-specific patterns in the epididymis. Immunoblot analysis revealed relatively equal levels of protein for TLRs 1, 2, 4, and 6 in testis, all regions of the epididymis and vas deferens, and lower levels of TLRs 3, 5, and 9-11. TLR7 was primarily detected in the testis. The TLR adapter proteins, myeloid differentiation primary response gene 88 and TLR adaptor molecule 1, as well as v-rel reticuloendotheliosis viral oncogene homolog and NFKBIA, were prominent in testis, epididymis, and vas deferens. The abundant expression of a majority of TLR family members together with expression of TLR adaptors and activation targets provides strong evidence that TLRs play important roles in innate immunity of the male reproductive tract.
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Affiliation(s)
- M A Palladino
- Department of Biology, Monmouth University, West Long Branch, NJ 07764, USA.
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Shayu D, Chennakesava CS, Rao AJ. Differential expression and antibacterial activity of WFDC10A in the monkey epididymis. Mol Cell Endocrinol 2006; 259:50-6. [PMID: 16996203 DOI: 10.1016/j.mce.2006.08.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/23/2006] [Revised: 08/07/2006] [Accepted: 08/15/2006] [Indexed: 11/24/2022]
Abstract
The ability of the epididymis to perform its diverse functions stems from its regionalized gene and protein expression patterns. The differences in the gene expression patterns of the caput and cauda regions of the bonnet monkey epididymis were compared using the technique of differential display reverse transcriptase polymerase chain reaction. A transcript showing homology to human whey acidic protein 10 (hWFDC10A) was highly expressed in the monkey caput region. A peptide P2 was designed spanning a region of the monkey WFDC10A (mWFDC10A), which could inhibit the growth of gram-negative bacterial strains of Escherichia coli. P2 could permeabilize the bacterial cell membrane but was unable to permeabilize mammalian cells as evidenced by the lack of hemolysis upon incubation with the peptide. Expression of genes such as mWFDC10A may be essential in providing the first line of defense against microbial infections to the epididymal tract and thus rendering protection to the male gametes sheltered within the epididymis.
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Affiliation(s)
- D Shayu
- Department of Biochemistry, Indian Institute of Science, Bangalore 560012, India
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Yenugu S, Hamil KG, Grossman G, Petrusz P, French FS, Hall SH. Identification, cloning and functional characterization of novel sperm associated antigen 11 (SPAG11) isoforms in the rat. Reprod Biol Endocrinol 2006; 4:23. [PMID: 16643671 PMCID: PMC1524968 DOI: 10.1186/1477-7827-4-23] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/07/2006] [Accepted: 04/28/2006] [Indexed: 01/16/2023] Open
Abstract
BACKGROUND Sperm binding proteins and their C-terminal peptides of the Sperm Associated Antigen 11 (SPAG11) family were found to play an important role in epididymal innate immunity in addition to their role in sperm maturation. However, the expression of Spag11 transcripts in rodents is not well documented. METHODS Computational analysis was employed to identify novel Spag11 isoforms in the rat. RT-PCR analyses were carried out on RNAs isolated from the male reproductive tract tissues of rat using gene specific primers for Spag11c and Spag11t. The identities of PCR products were confirmed by sequencing. Tissue distribution, developmental expression and androgen regulation of Spag11t and Spag11c were studied using RT-PCR. The antimicrobial activities of recombinant Spag11t and Spag11c were tested against E coli in a colony forming unit assay. RESULTS In this study, we identified two novel Spag11 transcripts, namely, Spag11t and Spag11c derived from the long arm of chromosome 16 in the rat (Rattus norvegicus), using both in silico and molecular biology approaches. Spag11c is expressed in all three regions of the epididymis, in testis and in ovary but is absent from the seminal vesicle. Spag11t expression is confined to the caput and it is not expressed in the testis, seminal vesicle or ovary. Age dependent expression of Spag11t and Spag11c was observed in the epididymides of rats (10-60 day old). Their expression was found to be most abundant in the adult rat (60 day) suggesting roles in mature reproductive function. Further, both Spag11t and Spag11c expression was down regulated in castrated rat epididymides and the expression was maintained in the testosterone replaced castrated rats. SPAG11C is a potent antibacterial agent. SPAG11T also displayed bactericidal capacity although weaker than SPAG11C and SPAG11E. CONCLUSION The abundant expression of Spag11t and Spag11c in the male reproductive tract suggests an important role in male reproductive tract immunity. Their expression is developmentally regulated and androgen dependent. Characterization of novel SPAG11 isoforms will contribute to our understanding of the role of epididymal proteins in sperm maturation and innate immunity.
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Affiliation(s)
- Suresh Yenugu
- Laboratories for Reproductive Biology, Department of Pediatrics, University of North Carolina, Chapel Hill, NC 27599-7500, USA
- Department of Biochemistry and Molecular Biology, Pondicherry University, Pondicherry, 605014, India
| | - Katherine G Hamil
- Laboratories for Reproductive Biology, Department of Pediatrics, University of North Carolina, Chapel Hill, NC 27599-7500, USA
| | - Gail Grossman
- Department of Cell and Developmental Biology, University of North Carolina, Chapel Hill, NC 27599-7500, USA
| | - Peter Petrusz
- Department of Cell and Developmental Biology, University of North Carolina, Chapel Hill, NC 27599-7500, USA
| | - Frank S French
- Laboratories for Reproductive Biology, Department of Pediatrics, University of North Carolina, Chapel Hill, NC 27599-7500, USA
| | - Susan H Hall
- Laboratories for Reproductive Biology, Department of Pediatrics, University of North Carolina, Chapel Hill, NC 27599-7500, USA
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16
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Yenugu S, Hamil KG, French FS, Hall SH. Antimicrobial Actions of Human and Macaque Sperm Associated Antigen (SPAG) 11 Isoforms: influence of the N-terminal peptide. Mol Cell Biochem 2006; 284:25-37. [PMID: 16411022 DOI: 10.1007/s11010-005-9009-2] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2005] [Accepted: 09/15/2005] [Indexed: 11/30/2022]
Abstract
In addition to their role in sperm maturation, recent evidence has indicated that epididymal proteins have a role in male reproductive tract innate immunity. Herein we demonstrate that human and macaque epididymal protein isoforms in the SPAG (sperm associated antigen) 11 family, full length SPAG11C, K and L exhibit potent antibacterial activity against E. coli. Analysis of activities of the N- and C-terminal domains revealed that the human N-terminal peptide is bactericidal, while the C-terminal domains that contain the defensin-like 6 cysteine array in SPAG11C and partial arrays in SPAG11K and SPAG11L, lack antibacterial activity. The N-terminal peptide does not appear to contain all the determinants of activity since full-length human SPAG11C is more active than the isolated N-terminal peptide and since sulfhydryl reduction and alkylation, which would affect primarily the C-terminal peptides, completely abolished activities of the whole proteins. These results suggest that the structure conferred by the disulfide bonds in human SPAG11C contributes to the antibacterial activity of the whole molecule. The activities of the N-terminal peptide and of full length human SPAG11C were somewhat reduced in increasing NaCl concentrations. In contrast, the antibacterial activities of full length macaque SPAG11C, K and L were unaffected by the presence of NaCl suggesting a mechanism in the macaque that is less dependent upon electrostatic interactions. SPAG11C, K and L disrupted E. coli membranes but had no effect on erythrocyte membranes. Inhibition of E. coli RNA, DNA and protein synthesis by nonlethal concentrations of SPAG11 isoforms indicated an additional mechanism of bacterial killing.
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Affiliation(s)
- Suresh Yenugu
- Laboratories for Reproductive Biology, Department of Pediatrics, University of North Carolina, Chapel Hill, 27599-7500, USA
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17
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Abstract
Antimicrobial peptides (AMPs) have been isolated and characterized from tissues and organisms representing virtually every kingdom and phylum. Their amino acid composition, amphipathicity, cationic charge, and size allow them to attach to and insert into membrane bilayers to form pores by 'barrel-stave', 'carpet' or 'toroidal-pore' mechanisms. Although these models are helpful for defining mechanisms of AMP activity, their relevance to resolving how peptides damage and kill microorganisms still needs to be clarified. Moreover, many AMPs employ sophisticated and dynamic mechanisms of action to carry out their likely roles in antimicrobial host defense. Recently, it has been speculated that transmembrane pore formation is not the only mechanism of microbial killing by AMPs. In fact, several observations suggest that translocated AMPs can alter cytoplasmic membrane septum formation, reduce cell-wall, nucleic acid, and protein synthesis, and inhibit enzymatic activity. In this review, we present the structures of several AMPs as well as models of how AMPs induce pore formation. AMPs have received special attention as a possible alternative way to combat antibiotic-resistant bacterial strains. It may be possible to design synthetic AMPs with enhanced activity for microbial cells, especially those with antibiotic resistance, as well as synergistic effects with conventional antibiotic agents that lack cytotoxic or hemolytic activity.
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Affiliation(s)
- Yoonkyung Park
- Research Center for Proteineous Materials, Chosun University, Dong-Ku, Kwangju, Korea
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Brogden KA. Antimicrobial peptides: pore formers or metabolic inhibitors in bacteria? Nat Rev Microbiol 2005; 3:238-50. [PMID: 15703760 DOI: 10.1038/nrmicro1098] [Citation(s) in RCA: 4048] [Impact Index Per Article: 213.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Antimicrobial peptides are an abundant and diverse group of molecules that are produced by many tissues and cell types in a variety of invertebrate, plant and animal species. Their amino acid composition, amphipathicity, cationic charge and size allow them to attach to and insert into membrane bilayers to form pores by 'barrel-stave', 'carpet' or 'toroidal-pore' mechanisms. Although these models are helpful for defining mechanisms of antimicrobial peptide activity, their relevance to how peptides damage and kill microorganisms still need to be clarified. Recently, there has been speculation that transmembrane pore formation is not the only mechanism of microbial killing. In fact several observations suggest that translocated peptides can alter cytoplasmic membrane septum formation, inhibit cell-wall synthesis, inhibit nucleic-acid synthesis, inhibit protein synthesis or inhibit enzymatic activity. In this review the different models of antimicrobial-peptide-induced pore formation and cell killing are presented.
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Affiliation(s)
- Kim A Brogden
- Department of Periodontics and Dows Institute for Dental Research, College of Dentistry, The University of Iowa, Iowa City, Iowa 52242, USA.
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