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Karachaliou CE, Kalbacher H, Voelter W, Tsitsilonis OE, Livaniou E. In Vitro Immunodetection of Prothymosin Alpha in Normal and Pathological Conditions. Curr Med Chem 2020; 27:4840-4854. [PMID: 31389310 DOI: 10.2174/0929867326666190807145212] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Revised: 05/20/2019] [Accepted: 07/22/2019] [Indexed: 02/06/2023]
Abstract
Prothymosin alpha (ProTα) is a highly acidic polypeptide, ubiquitously expressed in almost all mammalian cells and tissues and consisting of 109 amino acids in humans. ProTα is known to act both, intracellularly, as an anti-apoptotic and proliferation mediator, and extracellularly, as a biologic response modifier mediating immune responses similar to molecules termed as "alarmins". Antibodies and immunochemical techniques for ProTα have played a leading role in the investigation of the biological role of ProTα, several aspects of which still remain unknown and contributed to unraveling the diagnostic and therapeutic potential of the polypeptide. This review deals with the so far reported antibodies along with the related immunodetection methodology for ProTα (immunoassays as well as immunohistochemical, immunocytological, immunoblotting, and immunoprecipitation techniques) and its application to biological samples of interest (tissue extracts and sections, cells, cell lysates and cell culture supernatants, body fluids), in health and disease states. In this context, literature information is critically discussed, and some concluding remarks are presented.
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Affiliation(s)
- Chrysoula-Evangelia Karachaliou
- Institute of Nuclear & Radiological Sciences and Technology, Energy & Safety (INRASTES), National Centre for Scientific Research "Demokritos", 15310 Agia Paraskevi, Athens, Greece
| | - Hubert Kalbacher
- Interfaculty Institute of Biochemistry, University of Tuebingen, 72076 Tuebingen, Germany
| | - Wolfgang Voelter
- Interfaculty Institute of Biochemistry, University of Tuebingen, 72076 Tuebingen, Germany
| | - Ourania E Tsitsilonis
- Department of Biology, National and Kapodistrian University of Athens, 15701 Athens, Greece
| | - Evangelia Livaniou
- Institute of Nuclear & Radiological Sciences and Technology, Energy & Safety (INRASTES), National Centre for Scientific Research "Demokritos", 15310 Agia Paraskevi, Athens, Greece
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2
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Prothymosin α interacts with SET, ANP32A and ANP32B and other cytoplasmic and mitochondrial proteins in proliferating cells. Arch Biochem Biophys 2017; 635:74-86. [DOI: 10.1016/j.abb.2017.10.014] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Revised: 10/23/2017] [Accepted: 10/24/2017] [Indexed: 12/11/2022]
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3
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Freire M, Sarandeses CS, Covelo G, Díaz-Jullien C. Phosphorylation of Prothymosin α. An Approach to Its Biological Significance. VITAMINS AND HORMONES 2016; 102:73-99. [PMID: 27450731 DOI: 10.1016/bs.vh.2016.04.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Prothymosin α (ProTα), the precursor of the thymosin α1 and thymosin α11, is a 109-111 amino acids protein widely distributed in the mammalian tissues that is essential for the cell proliferation and survival through its implication on chromatin remodeling and in the proapoptotic activity. ProTα is phosphorylated at Thr residues by the M2 isoenzyme of the pyruvate kinase in a process that is dependent on the cell proliferation activity, which constitutes a novel dual functionality of this enzyme. The Thr residues phosphorylated are apparently dependent on the carcinogenic transformation of the cells. Thus, in normal lymphocytes residues Thr11 or Thr12 are phosphorylated in addition to a Thr7 residue, while in tumor cells Thr7 is the only residue phosphorylated. Phosphorylation of ProTα seems to be related to its antiapoptotic activity, although other possibilities cannot be discarded.
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Affiliation(s)
- M Freire
- Facultad de Biología, Universidade de Santiago de Compostela, Santiago de Compostela, Spain.
| | - C S Sarandeses
- Facultad de Biología, Universidade de Santiago de Compostela, Santiago de Compostela, Spain
| | - G Covelo
- Facultad de Biología, Universidade de Santiago de Compostela, Santiago de Compostela, Spain
| | - C Díaz-Jullien
- Facultad de Biología, Universidade de Santiago de Compostela, Santiago de Compostela, Spain
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Ferrara D, Pariante P, Di Matteo L, Serino I, Oko R, Minucci S. First evidence of prothymosin alpha localization in the acrosome of mammalian male gametes. J Cell Physiol 2013; 228:1629-37. [DOI: 10.1002/jcp.24332] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2012] [Accepted: 01/16/2013] [Indexed: 12/27/2022]
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Intracellular and extracellular cytokine-like functions of prothymosin α: implications for the development of immunotherapies. Future Med Chem 2012; 3:1199-208. [PMID: 21806381 DOI: 10.4155/fmc.11.72] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Prothymosin α (ProTα) is a 12.5-kDa, highly acidic protein widely distributed in different cell types expressed intracellularly and extracellularly. ProTα does not contain a secretion-signal sequence and is released by a nonclassical secretory pathway with a cargo protein. New findings on the extracellular function of ProTα have yielded exciting insights into the cytokine-like functions of this host protein that stimulates type I interferon via Toll-like receptor 4. Here, we discuss the intracellular function of ProTα, how new findings of cytokine-like activities of ProTα aid our understanding of mechanisms that direct ProTα functions, and the potential application of these new insights to the development of immunotherapies.
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Ueda H, Matsunaga H, Uchida H, Ueda M. Prothymosin α as robustness molecule against ischemic stress to brain and retina. Ann N Y Acad Sci 2010; 1194:20-6. [DOI: 10.1111/j.1749-6632.2010.05466.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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Prothymosin α and cell death mode switch, a novel target for the prevention of cerebral ischemia-induced damage. Pharmacol Ther 2009; 123:323-33. [DOI: 10.1016/j.pharmthera.2009.05.007] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2009] [Accepted: 05/11/2009] [Indexed: 12/17/2022]
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8
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Osman AM, Kol SV, Peijnenburg A, Blokland M, Pennings JLA, Kleinjans JCS, Loveren HV. Proteomic analysis of mouse thymoma EL4 cells treated with bis(tri-n-butyltin)oxide (TBTO). J Immunotoxicol 2009. [DOI: 10.1080/15476910903051723] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
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9
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Ueda H, Fujita R, Yoshida A, Matsunaga H, Ueda M. Identification of prothymosin-alpha1, the necrosis-apoptosis switch molecule in cortical neuronal cultures. ACTA ACUST UNITED AC 2007; 176:853-62. [PMID: 17353361 PMCID: PMC2064059 DOI: 10.1083/jcb.200608022] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
We initially identified a nuclear protein, prothymosin-α1 (ProTα), as a key protein inhibiting necrosis by subjecting conditioned media from serum-free cultures of cortical neurons to a few chromatography steps. ProTα inhibited necrosis of cultured neurons by preventing rapid loss of cellular adenosine triphosphate levels by reversing the decreased membrane localization of glucose transporters but caused apoptosis through up-regulation of proapoptotic Bcl2-family proteins. The apoptosis caused by ProTα was further inhibited by growth factors, including brain-derived neurotrophic factor. The ProTα-induced cell death mode switch from necrosis to apoptosis was also reproduced in experimental ischemia-reperfusion culture experiments, although the apoptosis level was markedly reduced, possibly because of the presence of growth factors in the reperfused serum. Knock down of PKCβII expression prevented this cell death mode switch. Collectively, these results suggest that ProTα is an extracellular signal protein that acts as a cell death mode switch and could be a promising candidate for preventing brain strokes with the help of known apoptosis inhibitors.
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Affiliation(s)
- Hiroshi Ueda
- Division of Molecular Pharmacology and Neuroscience, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki 852-8521, Japan.
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Jin Y, Cao C, Li P, Liu X, Huang W, Li C, Ma Q. Boosting immune response to hepatitis B DNA vaccine by coadministration of Prothymosin alpha-expressing plasmid. CLINICAL AND DIAGNOSTIC LABORATORY IMMUNOLOGY 2006; 12:1364-9. [PMID: 16339058 PMCID: PMC1317068 DOI: 10.1128/cdli.12.12.1364-1369.2005] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
DNA vaccines induce protective humoral and cell-mediated immune responses in several animal models. However, compared to conventional vaccines, DNA vaccines usually induce poor antibody responses. In this study, we report that coadministration of a hepatitis B virus (HBV) DNA vaccine with prothymosin alpha as an adjuvant improves antibody responses to HBV S antigen. We also observed higher seroconversion rates and higher antibody titers. Prothymosin alpha appears to increase the number and affinity of hepatitis B surface antigen-specific, gamma interferon-secreting T cells and to enhance cellular immune response to the PreS2S DNA vaccine. Interestingly, administering the DNA separately from the prothymosin alpha plasmid abrogated the enhancement of DNA vaccine potency. The results suggest that prothymosin alpha may be a promising adjuvant for DNA vaccines.
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Affiliation(s)
- Yanwen Jin
- P.O. Box 130(8), 27 Taiping Rd., Beijing 100850, China.
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Okamoto K, Isohashi F. Macromolecular translocation inhibitor II (Zn(2+)-binding protein, parathymosin) interacts with the glucocorticoid receptor and enhances transcription in vivo. J Biol Chem 2005; 280:36986-93. [PMID: 16150697 DOI: 10.1074/jbc.m506056200] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Macromolecular translocation inhibitor II (MTI-II), which was first identified as an in vitro inhibitor of binding between the highly purified glucocorticoid receptor (GR) and isolated nuclei, is an 11.5-kDa Zn(2+)-binding protein that is also known as ZnBP or parathymosin. MTI-II is a small nuclear acidic protein that is highly conserved in rats, cows, and humans and widely distributed in mammalian tissues, yet its physiological function is unknown. To elucidate its in vivo function in relation to GR, we transiently transfected mammalian cells with an expression plasmid encoding MTI-II. Unexpectedly, we found that the expression of MTI-II enhances the transcriptional activity of GR. The magnitude of the transcriptional enhancement induced by MTI-II is comparable with that induced by the steroid receptor coactivator SRC-1. In contrast, MTI-II had little effect on the transcriptional activity of estrogen receptor. Immunoprecipitation analysis showed that in the presence of glucocorticoid hormone, GR coprecipitates with MTI-II, and, vice versa, MTI-II coprecipitates with GR. The expression of various deletion mutants of MTI-II revealed that the central acidic domain is essential for the enhancement of GR-dependent transcription. Microscopic analysis of MTI-II fused to green fluorescent protein and GR fused to red fluorescent protein in living HeLa cells showed that MTI-II colocalizes with GR in discrete subnuclear domains in a hormone-dependent manner. Coexpression of MTI-II with the coactivator SRC-1 or p300 further enhances GR-dependent transcription. Immunoprecipitation analysis showed that in the presence of glucocorticoid hormone, p300 and CREB-binding protein are coprecipitated with MTI-II. Furthermore, the knockdown of endogenous MTI-II by RNAi reduces the transcriptional activity of GR in cells. Moreover, expression of MTI-II enhances the glucocorticoid-dependent transcription of the endogenous glucocorticoid-inducible enzyme in cells. Taken together, these results indicate that MTI-II enhances GR-dependent transcription via a direct interaction with GR in vivo. Thus, MTI-II is a new member of the GR-coactivator complex.
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Affiliation(s)
- Kazuki Okamoto
- Department of Biochemistry, St. Marianna University School of Medicine, Sugao, Miyamae-ku, Kawasaki, Kanagawa 216-8511, Japan.
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New Functions of a Well-Known Protein: Prothymosin α Is Involved in Protecting Cells from Apoptosis and Oxidative Stress. Mol Biol 2005. [DOI: 10.1007/s11008-005-0079-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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13
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Shiau AL, Chen CC, Yo YT, Chu CY, Wang SY, Wu CL. Enhancement of humoral and cellular immune responses by an oral Salmonella choleraesuis vaccine expressing porcine prothymosin alpha. Vaccine 2005; 23:5563-71. [PMID: 16125286 DOI: 10.1016/j.vaccine.2005.07.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2005] [Revised: 05/09/2005] [Accepted: 07/04/2005] [Indexed: 10/25/2022]
Abstract
Previously, we showed that murine prothymosin alpha (ProT) enhances the efficacy of a pseudorabies DNA vaccine delivered by bacterial vectors. In this study, we cloned and sequenced the cDNA for porcine ProT. The deduced amino acid sequence of porcine ProT exhibited high homology to ProT from other mammals. Oral Salmonella choleraesuis vaccine carrying the ProT eukaryotic expression plasmid protected mice against virulent S. choleraesuis challenge. The adjuvant effect of ProT on humoral and cellular immune responses enhanced protective efficacy of the vaccine. Furthermore, both humoral and cellular immune responses played roles in the protective immune responses induced by the vaccine. Collectively, our results show that delivery of the ProT gene carried by attenuated S. choleraesuis augmented the immunogenicity of oral S. choleraesuis vaccine.
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Affiliation(s)
- Ai-Li Shiau
- Department of Microbiology and Immunology, National Cheng Kung University Medical College, Tainan 701, Taiwan
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Chen C, Li M, Yang H, Chai H, Fisher W, Yao Q. Roles of thymosins in cancers and other organ systems. World J Surg 2005; 29:264-70. [PMID: 15706436 DOI: 10.1007/s00268-004-7817-2] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Thymosins are small peptides, originally identified from the thymus, but now known to be more widely distributed in many tissues and cells. Thymosins are divided into three main groups, alpha-, beta-, : and gamma-thymosins, based on their isoelectric points. alpha-thymosins (ProTalpha, Talphal) have nuclear localization and are involved in transcription and/or DNA replications; whereas beta-thymosins (Tbeta4, Tbeta10, Tbetal5) have cytoplasmic localization and show high affinity to G-actin for cell mobility. Furthermore, it is well known that both alpha- and beta-thymosins play important roles in modulating immune response, vascular biology, and cancer pathogenesis. More importantly, thymosins may have significant clinical applications. They may serve as molecular markers for the diagnosis and prognosis of certain diseases. In addition, they could be molecular targets of certain diseases or be used as therapeutic agents to treat certain diseases. However, the molecular mechanisms of action of thymosins are largely unknown. This review not only presents recent advances of basic science research of thymosins and their clinical applications but provides thoughtful views for future directions of investigation on thymosins.
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Affiliation(s)
- Changyi Chen
- Molecular Surgeon Research Center, Michael E. DeBakey Department of Surgery, Baylor College of Medicine, Houston, Texas 77030, USA,
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Li KJ, Shiau AL, Chiou YY, Yo YT, Wu CL. Transgenic overexpression of prothymosin α induces development of polycystic kidney disease11See Editorial by Gattone, p. 2063. Kidney Int 2005; 67:1710-22. [PMID: 15840017 DOI: 10.1111/j.1523-1755.2005.00268.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Polycystic kidney disease (PKD) is a genetic disorder characterized by development of renal cysts and progressive renal dysfunction. Renal tissues from both PKD patients and rodent models of PKD show elevated c-myc expression. Prothymosin alpha (ProT) is positively regulated by c-myc through binding to the E box of its promoter. Through creating transgenic mice and clinical studies, we sought to investigate whether ProT overexpression contributes to PKD development. METHODS ProT heterozygous and homozygous transgenic mice were generated and characterized. Morphologic, histologic, immunohistochemical, and biochemical analyses of the transgenic mice were performed. RESULTS Two transgenic lines that represented integration at two different loci of the chromosomes were generated. ProT overexpression in the kidneys of homozygous transgenic mice induced a PKD phenotype, which included polycystic kidneys, elevated blood urea nitrogen (BUN), and lethality at about 10 days of age. Similar overexpression pattern of ProT was noted in cystic kidneys of the transgenic mice as well as in human autosomal-recessive PKD (ARPKD) and autosomal-dominant PKD (ADPKD) kidneys. ProT protein levels in the kidneys and urine as well as renal mRNA level of epithelial growth factor receptor (EGFR) of homozygous ProT transgenic mice were significantly higher than heterozygous or nontransgenic littermates. Furthermore, the heterozygous transgenic mice at 17 months of age also developed mild cystic kidneys. CONCLUSION Transgenic mice overexpressing ProT represent a novel model for PKD and may provide insights into PKD development. ProT, like c-myc and EGFR, may contribute to the development of renal cysts and may be a potential noninvasive diagnostic molecule of PKD.
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Affiliation(s)
- Kuo-Jung Li
- Institute of Basic Medical Sciences, National Cheng Kung University Medical College, Tainan, Taiwan
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Yang CH, Murti A, Baker SJ, Frangou-Lazaridis M, Vartapetian AB, Murti KG, Pfeffer LM. Interferon induces the interaction of prothymosin-alpha with STAT3 and results in the nuclear translocation of the complex. Exp Cell Res 2004; 298:197-206. [PMID: 15242774 DOI: 10.1016/j.yexcr.2004.04.008] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2003] [Revised: 03/05/2004] [Indexed: 11/21/2022]
Abstract
Interferons (IFNs) play critical roles in host defense by modulating the expression of various genes via tyrosine phosphorylation of STAT transcription factors. Many cytokines including IFNs induce tyrosine phosphorylation of the STAT3 transcription factor, which regulates acute phase gene expression. Using the yeast two-hybrid interaction trap, in which a tyrosine kinase is introduced into the yeast to allow tyrosine phosphorylation of bait proteins, prothymosin-alpha (ProTalpha) was identified to interact with the amino terminal half of tyrosine-phosphorylated STAT3. ProTalpha is a small, acidic, extremely abundant, and essential protein that may play a role in chromatin remodeling, and has been implicated in regulating the growth and survival of mammalian cells. Besides the interaction of tyrosine-phosphorylated STAT3 with ProTalpha in yeast cells, IFN induced the interaction of ProTalpha with STAT3 in mammalian cells, and this interaction was dependent on the tyrosine phosphorylation of STAT3. Moreover, IFNalpha induces the translocation of STAT3 and ProTalpha from the cytoplasm to the nucleus where these proteins colocalize. Since ProTalpha has an extremely strong nuclear localization and STAT proteins apparently lack any nuclear localization signals, the association of STAT3 with ProTalpha may provide a mechanism to result in STAT localization in the nucleus.
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Affiliation(s)
- Chuan He Yang
- Department of Pathology and Laboratory Medicine, University of Tennessee Health Science Center, Memphis 38103, USA
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Hannappel E, Huff T. The thymosins. Prothymosin alpha, parathymosin, and beta-thymosins: structure and function. VITAMINS AND HORMONES 2003; 66:257-96. [PMID: 12852257 DOI: 10.1016/s0083-6729(03)01007-0] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The studies on thymosins were initiated in 1965, when the group of A. White searched for thymic factors responsible for the physiological functions of thymus. To restore thymic functions in thymic-deprived or immunodeprived animals, as well as in humans with primary immuno-deficiency diseases and in immunosuppressed patients, a standardized extract from bovine thymus gland called thymosin fraction 5 was prepared. Thymosin fraction 5 indeed improved immune response. It turned out that thymosin fraction 5 consists of a mixture of small polypeptides. Later on, several of these peptides (polypeptide beta 1, thymosin alpha 1, prothymosin alpha, parathymosin, and thymosin beta 4) were isolated and tested for their biological activity. The research of many groups has indicated that none of the isolated peptides is really a thymic hormone; nevertheless, they are biologically important peptides with diverse intracellular and extracellular functions. Studies on these functions are still in progress. The current status of knowledge of structure and functions of the thymosins is discussed in this review.
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Affiliation(s)
- Ewald Hannappel
- Institute for Biochemistry/Faculty of Medicine, University of Erlangen-Nürnberg, 91054 Erlangen, Germany
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Sarandeses CS, Covelo G, Díaz-Jullien C, Freire M. Prothymosin alpha is processed to thymosin alpha 1 and thymosin alpha 11 by a lysosomal asparaginyl endopeptidase. J Biol Chem 2003; 278:13286-93. [PMID: 12554742 DOI: 10.1074/jbc.m213005200] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Thymosin alpha(1) (T alpha(1)) and thymosin T alpha(11) (T alpha(11)) are polypeptides with immunoregulatory properties first isolated from thymic extracts, corresponding to the first 28 and 35 amino acid residues, respectively, of prothymosin alpha (ProT alpha), a protein involved in chromatin remodeling. It has been widely supposed that these polypeptides are not natural products of the in vivo processing of ProT alpha, since neither was found in extracts in which proteolysis was prevented. Here we show that a lysosomal asparaginyl endopeptidase is able to process ProT alpha to generate T alpha(1) and T alpha(11). In view of its catalytic properties and structural and immunological analyses, this protease was identified as mammalian legumain. It selectively cleaves some of the asparaginyl-glycine residues in the ProT alpha sequence; specifically, Asn(28)-Gly(29) and Asn(35)-Gly(36) residues are cleaved with similar efficiency in vitro to generate T alpha(1) and T alpha(11), respectively. By contrast T alpha(1) is the main product detected in vivo, free in the cytosol, at concentrations similar to that of ProT alpha. The data here reported demonstrate that T alpha(1) is not an artifact but rather is naturally present in diverse mammalian tissues and raise the possibility that it has a functional role.
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Affiliation(s)
- Concepción S Sarandeses
- Departamento de Bioquímica y Biología Molecular, Facultad de Biología, Universidad de Santiago de Compostela, Santiago de Compostela 15782, Spain
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Evstafieva AG, Belov GA, Rubtsov YP, Kalkum M, Joseph B, Chichkova NV, Sukhacheva EA, Bogdanov AA, Pettersson RF, Agol VI, Vartapetian AB. Apoptosis-related fragmentation, translocation, and properties of human prothymosin alpha. Exp Cell Res 2003; 284:211-23. [PMID: 12651154 DOI: 10.1016/s0014-4827(02)00047-2] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Human prothymosin alpha is a proliferation-related nuclear protein undergoing caspase-mediated fragmentation in apoptotic cells. We show here that caspase-3 is the principal executor of prothymosin alpha fragmentation in vivo. In apoptotic HeLa cells as well as in vitro, caspase-3 cleaves prothymosin alpha at one major carboxy terminal (DDVD(99)) and several suboptimal sites. Prothymosin alpha cleavage at two amino-terminal sites (AAVD(6) and NGRD(31)) contributes significantly to the final pattern of prothymosin alpha fragmentation in vitro and could be detected to occur in apoptotic cells. The major caspase cleavage at D(99) disrupts the nuclear localization signal of prothymosin alpha, which leads to a profound alteration in subcellular localization of the truncated protein. By using a set of anti-prothymosin alpha monoclonal antibodies, we were able to observe nuclear escape and cell surface exposure of endogenous prothymosin alpha in apoptotic, but not in normal, cells. We demonstrate also that ectopic production of human prothymosin alpha and its mutants with nuclear or nuclear-cytoplasmic localization confers increased resistance of HeLa cells toward the tumor necrosis factor-induced apoptosis.
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Affiliation(s)
- Alexandra G Evstafieva
- Belozersky Institute of Physico-Chemical Biology, Moscow State University, 119992, Moscow, Russia
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Sukhacheva EA, Evstafieva AG, Fateeva TV, Shakulov VR, Efimova NA, Karapetian RN, Rubtsov YP, Vartapetian AB. Sensing prothymosin alpha origin, mutations and conformation with monoclonal antibodies. J Immunol Methods 2002; 266:185-96. [PMID: 12133636 DOI: 10.1016/s0022-1759(02)00098-4] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
To overcome poor immunogenicity of prothymosin alpha, a small and highly acidic nuclear protein involved in cell proliferation, production of anti-prothymosin alpha antibodies in mice immunized with free human prothymosin alpha, with prothymosin alpha coupled to different carriers and with prothymosin alpha fused to green fluorescent protein was assessed. Fusing prothymosin alpha to green fluorescent protein turned out to be the superior approach resulting in production of high titer anti-prothymosin alpha antibodies. From these studies, two highly specific anti-prothymosin alpha monoclonal antibodies recognizing epitopes within the amino terminal (2F11) and middle (4F4) portions of the human prothymosin alpha molecule were obtained and characterized. As expected, the 2F11 antibody displayed broad species specificity, whereas the 4F4 antibody appeared to be species-specific permitting discrimination of human versus rat protein. Furthermore, a combination of point mutations in prothymosin alpha that alter the properties of the protein precluded recognition by the 4F4 antibody. Intramolecular masking of the 4F4 epitope in prothymosin alpha fused to the Tat transduction peptide of human immunodeficiency virus type 1 was observed. The anti-prothymosin alpha antibodies obtained were suitable for precipitation of human prothymosin alpha from HeLa cell lysates and for immunolocalization of the endogenous prothymosin alpha within the cells. Fusion with green fluorescent protein may thus be helpful in raising antibodies against 'problematic' proteins.
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Affiliation(s)
- Elena A Sukhacheva
- Shemiakin and Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
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Aniello F, Branno M, De Rienzo G, Ferrara D, Palmiero C, Minucci S. First evidence of prothymosin alpha in a non-mammalian vertebrate and its involvement in the spermatogenesis of the frog Rana esculenta. Mech Dev 2002; 110:213-7. [PMID: 11744386 DOI: 10.1016/s0925-4773(01)00569-x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
A cDNA clone encoding for a Prothymosin alpha (Prot-alpha) has been isolated and characterized from the testis of the frog Rana esculenta. Frog Prothymosin alpha (fProt-alpha) predicted a 109 amino acid protein with a high homology to the mammalian Prot-alpha. fProt-alpha contains 28 aspartic and 25 glutamic acid residues and presents the typical basic KKQK amino acid sequence in the close carboxyl terminal region. Northern blot analysis revealed that fProt-alpha is highly expressed in the testis. A different expression of fProt-alpha transcript was found during the frog reproductive cycle with a peak in September/October in concomitance with germ cell maturation, strongly suggesting a role for this protein in the testicular activity. In situ hybridization evidenced that the only germ cells expressing fProt-alpha are the primary and secondary spermatocytes; in addition, the hybridization signal was stronger in the October testis. Taken together, our findings indicate that fProt-alpha might contribute to the efficiency of frog spermatogenesis with a role during the meiosis. This study is the first report on the isolation and characterization of a Prot-alpha in a non-mammalian vertebrate. In addition, our results indicate that the testis of the frog R. esculenta may be a useful model to increase the knowledge concerning the physiological role of Prot-alpha in vertebrates.
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Affiliation(s)
- Francesco Aniello
- Dipartimento di Genetica, Biologia Generale e Molecolare Università degli Studi di Napoli Federico II - Via Mezzocannone 8, 80138 Naples, Italy
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22
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Piñeiro A, Begoña Bugia M, Pilar Arias M, Cordero OJ, Nogueira M. Identification of receptors for prothymosin alpha on human lymphocytes. Biol Chem 2001; 382:1473-82. [PMID: 11727831 DOI: 10.1515/bc.2001.181] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Prothymosin alpha (ProTalpha) is a highly conserved and widely distributed protein whose physiological functions remain elusive. In previous work we identified high and low affinity-binding sites for ProTalpha in lymphoid cells. Here we demonstrate, by affinity cross-linking and affinity chromatography, the existence of three binding partners (31, 29, and 19 kDa) for ProTalpha in the membrane of PHA-activated lymphoblasts. These surface molecules possess the expected affinity and specificity for a ProTalpha receptor. Examination of the expression of this complex of molecules by flow cytometry reveals that they bind ProTalpha in a specific and saturable way. In addition, the distribution of the receptor on the cell surface was studied by fluorescence microscopy; a cap-like structure at one of the poles of the cells was identified. These results represent a new and promising approach in the research on ProTalpha, opening the way toward the understanding of the molecular mechanism of action of this protein.
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Affiliation(s)
- A Piñeiro
- Department of Biochemistry and Molecular Biology, Faculty of Biology, University of Santiago de Compostela, Spain
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23
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Shiau AL, Chu CY, Su WC, Wu CL. Vaccination with the glycoprotein D gene of pseudorabies virus delivered by nonpathogenic Escherichia coli elicits protective immune responses. Vaccine 2001; 19:3277-84. [PMID: 11312026 DOI: 10.1016/s0264-410x(00)00542-9] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Attenuated intracellular bacteria, such as Salmonella and Shigella, have been exploited to act as gene delivery vectors. In this study, we report that nonpathogenic, live Escherichia coli can be used for the delivery of DNA vaccines in vivo, leading to generation of immune responses against plasmid-encoded foreign antigens. The pseudorabies virus (PrV) DNA vaccine carrying the glycoprotein D (gD) gene delivered by E. coli was able to induce protective immune responses in mice against a lethal PrV challenge. Co-delivery of E. coli carrying plasmid DNA encoding prothymosin alpha enhanced cellular immune responses to the PrV DNA vaccine delivered by E. coli. Our results suggest that nonpathogenic E. coli may be used as a vector for DNA vaccines in veterinary uses.
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MESH Headings
- 3T3 Cells
- Adjuvants, Immunologic/administration & dosage
- Animals
- Escherichia coli/genetics
- Escherichia coli/pathogenicity
- Female
- Genes, Viral
- Genetic Vectors
- Herpesvirus 1, Suid/genetics
- Herpesvirus 1, Suid/immunology
- Herpesvirus 1, Suid/pathogenicity
- Lymphocyte Activation
- Mice
- Mice, Inbred BALB C
- Protein Precursors/genetics
- Protein Precursors/immunology
- Pseudorabies/immunology
- Pseudorabies/prevention & control
- Pseudorabies Vaccines/administration & dosage
- Pseudorabies Vaccines/genetics
- Pseudorabies Vaccines/immunology
- Swine
- Swine Diseases/immunology
- Swine Diseases/prevention & control
- T-Lymphocytes, Cytotoxic/immunology
- Thymosin/analogs & derivatives
- Thymosin/genetics
- Thymosin/immunology
- Vaccines, DNA/administration & dosage
- Vaccines, DNA/genetics
- Vaccines, DNA/immunology
- Viral Envelope Proteins/genetics
- Viral Envelope Proteins/immunology
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Affiliation(s)
- A L Shiau
- Department of Microbiology, National Cheng Kung University Medical College, 701, Tainan, Taiwan
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24
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Freire J, Covelo G, Sarandeses C, Díaz-Jullien C, Freire M. Identification of nuclear-import and cell-cycle regulatory proteins that bind to prothymosin α. Biochem Cell Biol 2001. [DOI: 10.1139/o00-098] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Prothymosin α (ProTα) is a nuclear protein that is widely distributed in mammalian tissues, and is thought to play a role in cell proliferation. In an attempt to shed light on this role, affinity chromatography on ProTα-Sepharose columns was used to identify proteins in subcellular extracts of transformed human lymphocytes (NC37 cells) that interact with ProTα in vitro, and thus may interact with ProTα in vivo. Immunoblotting techniques were used to screen the ProTα-binding fractions for histones and other proteins involved in nuclear transport and cell-cycle control. The most abundant ProTα-binding proteins were histones H2A, H2B, H3, and H4. Of the nuclear-transport proteins, karyopherin β1, Rch-1, Ran, and RCC1 were detected at high concentrations; NTF2, nucleoporin p62, and Hsp70 were detected at low concentrations; while tranportin, CAS, and Ran BP1 were not detected. Of the cell-cycle control proteins, PCNA, Cdk2, and cyclin A were detected at high concentrations; cdc2, Cdk4, and cyclin B were detected at very low concentrations; while cyclin D1, cyclin D3, Cip1, and Kip1 were not detected. These results suggest (i) that ProTα is transported into the nucleus by the karyopherin β1 - Rch-1 complex, and (ii) that ProTα may interact in the nucleus with proteins involved in DNA metabolism and cell-cycle control.Key words: prothymosin α, histone-binding proteins, nuclear transport proteins, cell-cycle proteins, chromatin remodeling.
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25
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Enkemann SA, Ward RD, Berger SL. Mobility within the nucleus and neighboring cytosol is a key feature of prothymosin-alpha. J Histochem Cytochem 2000; 48:1341-55. [PMID: 10990488 DOI: 10.1177/002215540004801005] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Prothymosin alpha is a small, unfolded, negatively charged, poorly antigenic mammalian protein with a potent nuclear localization signal. Although it is apparently essential for growth, its precise function is unknown. We examined the location and behavior of the protein bearing different epitope tags using in situ immunolocalization in COS-1 and NIH3T3 cells. Tagged prothymosin alpha appeared to be punctate and widely dispersed throughout the nucleus, with the exception of the nucleolus. A tiny cytoplasmic component, which persisted in the presence of cycloheximide and actinomycin D during interphase, became pronounced immediately before, during, and after mitosis. When nuclear uptake was abrogated, small tagged prothymosin alpha molecules, but not prothymosin alpha fused to beta-galactosidase, accumulated significantly in the cytoplasm. Tagged prothymosin alpha shared domains with mobile proteins such as Ran, transportin, and karyopherin beta, which also traverse the nuclear membrane, and co-localized with active RNA polymerase II. Mild digitonin treatment resulted in nuclei devoid of prothymosin alpha. The data do not support tight binding to any nuclear component. Therefore, we propose that prothymosin alpha is a highly diffusible bolus of salt and infer that it facilitates movement of charged molecules in highly charged environments within and near the nucleus.
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Affiliation(s)
- S A Enkemann
- Section on Genes and Gene Products, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA
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26
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Abstract
Prothymosin alpha (ProTalpha) is a highly acidic and small protein of only 111 amino acids with an unusual primary structure. One would expected it to play an essential role in the organism, as it has a wide distribution and is high conserved among mammals, yet its exact function remains elusive. Despite the number of effects described for ProTalpha, intracellular and extracellular, none are accepted as its physiological role. Furthermore, many other aspects of its biology still remain obscure. In this review, we discuss the structural properties, location, gene family, functions and immunomodulatory activities of and cellular receptors for ProTalpha. These topics are addressed in an attempt to reconcile opposing outlooks while emphasizing those points where scant investigations do exist. We have also re-evaluated some previous results in light of the structural properties of ProTalpha and have found that molecular mimetism could be the underlying basis. This molecular mimicry hypothesis provides a clue that must not be overlooked for a realistic appraisal of future results.
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Affiliation(s)
- A Piñeiro
- Department of Biochemistry and Molecular Biology, Faculty of Biology, University of Santiago de Compostela. 15706, Santiago de Compostela, Spain
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27
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Shakulov VR, Vorobjev IA, Rubtsov YP, Chichkova NV, Vartapetian AB. Interaction of yeast importin alpha with the NLS of prothymosin alpha is insufficient to trigger nuclear uptake of cargos. Biochem Biophys Res Commun 2000; 274:548-52. [PMID: 10913375 DOI: 10.1006/bbrc.2000.3183] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
A proliferation-related human protein prothymosin alpha displays exclusively nuclear localization when produced in human and Saccharomyces cerevisiae cells, whereas its isolated bipartite NLS confers nuclear targeting of the GFP reporter in human but not in yeast cells. To test whether this observation is indicative of the existence of specific requirements for nuclear targeting of proteins in yeast, a set of prothymosin alpha deletion mutants was constructed. Subcellular localization of these mutants fused to GFP was determined in yeast and compared with their ability to bind yeast importin alpha (Srp1p) in vitro. The NLS of prothymosin alpha turned out to be both necessary and sufficient to provide protein recognition by importin alpha. However, the NLS-importin alpha interaction did not ensure nuclear targeting of prothymosin alpha derivatives. This defect could be complemented by adding distinct prothymosin alpha sequences to the NLS-containing import substrate, possibly by providing binding site(s) for additional components of the yeast nuclear import machinery.
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Affiliation(s)
- V R Shakulov
- Belozersky Institute of Physico-Chemical Biology and Center of Molecular Medicine, Moscow State University, Moscow, 119899, Russia
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28
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Evstafieva AG, Belov GA, Kalkum M, Chichkova NV, Bogdanov AA, Agol VI, Vartapetian AB. Prothymosin alpha fragmentation in apoptosis. FEBS Lett 2000; 467:150-4. [PMID: 10675528 DOI: 10.1016/s0014-5793(00)01139-x] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
We observed fragmentation of an essential proliferation-related human nuclear protein prothymosin alpha in the course of apoptosis induced by various stimuli. Prothymosin alpha cleavage occurred at the DDVD(99) motif. In vitro, prothymosin alpha could be cleaved at D(99) by caspase-3 and -7. Caspase hydrolysis disrupted the nuclear localization signal of prothymosin alpha and abrogated the ability of the truncated protein to accumulate inside the nucleus. Prothymosin alpha fragmentation may therefore be proposed to disable intranuclear proliferation-related function of prothymosin alpha in two ways: by cleaving off a short peptide containing important determinants, and by preventing active nuclear uptake of the truncated protein.
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Affiliation(s)
- A G Evstafieva
- Belozersky Institute of Physico-Chemical Biology, Center of Molecular Medicine, Moscow State University, Moscow, Russia
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29
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Enkemann SA, Wang RH, Trumbore MW, Berger SL. Functional discontinuities in prothymosin alpha caused by caspase cleavage in apoptotic cells. J Cell Physiol 2000; 182:256-68. [PMID: 10623890 DOI: 10.1002/(sici)1097-4652(200002)182:2<256::aid-jcp15>3.0.co;2-n] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Our study examines the effect of apoptosis on prothymosin alpha, an abundant, nuclear protein intimately involved with proliferation of all mammalian cells. When HeLa cells were treated with actinomycin D, with etoposide, or with staurosporine following synchronization with hydroxyurea, they underwent apoptosis based on several specific criteria, including fragmentation of DNA and activation of specific caspases. Similarly treated NIH3T3 cells arrested and displayed no indicators of apoptosis. In HeLa, but not in NIH3T3 cells, prothymosin alpha levels declined precipitously and a truncated version of the protein was formed. The following observations implicate caspase activity: (1) The truncated polypeptide arose only in the treated HeLa cell cultures. (2) The appearance of the truncated polypeptide coincided with the activation of caspase 3 and the cleavage of poly(ADP-ribose) polymerase, a known caspase substrate. (3) Carbobenzoxy-DEVD-fluoromethylketone, a cell-permeable caspase 3 inhibitor, blocked cleavage and degradation of prothymosin alpha. (4) The same inhibitor, when added to mixed extracts of apoptotic and normal cells, prevented cleavage of intact prothymosin alpha. (5) Recombinant caspase 3 and, to a much lesser extent, caspase 7 truncated purified prothymosin alpha. (6) In HeLa cells, cleavage occurred at three overlapping caspase 3-like sites with the consensus sequence D-X-X-D and released 10 to 14 residues from the carboxyl terminus, including the core nuclear localization signal. Two immediate consequences of the cleavage were observed: truncated prothymosin alpha was no longer confined to the nucleus and it was deficient in phosphate. These data suggest that the disabling of prothymosin alpha is a significant event in apoptosis. J. Cell. Physiol. 182:256-268, 2000. Published 2000 Wiley-Liss, Inc.
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Affiliation(s)
- S A Enkemann
- Section on Genes and Gene Products, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
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30
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Okamoto K, Isohashi F. Purification and primary structure of a macromolecular-translocation inhibitor II of glucocorticoid-receptor binding to nuclei from rat liver. Inhibitor II is the 11.5-kDa Zn2+-binding protein (parathymosin). EUROPEAN JOURNAL OF BIOCHEMISTRY 2000; 267:155-62. [PMID: 10601862 DOI: 10.1046/j.1432-1327.2000.00987.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The nuclear binding of the activated glucocorticoid-receptor (GR) is inhibited by endogenous macromolecules in vitro. Previously, we have separated the inhibitors into three species (MTI-I, MTI-II and MTI-III). In this study, we purified the most potent of the three species (MTI-II) from the livers of adrenalectomized rats to apparent homogeneity as judged by two-dimensional PAGE. Purified MTI-II inhibits GR binding to DNA containing glucocorticoid-response elements. To obtain the amino acid sequence of MTI-II, we digested the MTI-II with endopeptidases. The N-terminal amino acid sequences of the four digested fragments indicated that MTI-II is an 11.5-kDa Zn2+-binding protein (ZnBP, also known as parathymosin). Furthermore, we purified ZnBP to apparent homogeneity and found that it also inhibits GR binding to nuclei. ZnBP is known to be an abundant acidic protein involved in cell proliferation, and interacts with histone H1 or key enzymes of carbohydrate metabolism via its acidic domain. We also showed that the inhibition of GR binding to nuclei is mediated by the acidic domain of MTI-II (ZnBP, parathymosin) and that GR binds to the MTI-II affinity matrix. Our findings add a new biological function, i.e. the inhibition of GR binding to nuclei and DNA, to this ZnBP. Moreover, our findings suggest that the abundant acidic protein is involved in glucocorticoid action.
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Affiliation(s)
- K Okamoto
- Department of Biochemistry, St. Marianna University School of Medicine, Kanagawa, Japan
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31
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Enkemann SA, Pavur KS, Ryazanov AG, Berger SL. Does prothymosin alpha affect the phosphorylation of elongation factor 2? J Biol Chem 1999; 274:18644-50. [PMID: 10373476 DOI: 10.1074/jbc.274.26.18644] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Prothymosin alpha is a small, acidic, essential nuclear protein that plays a poorly defined role in the proliferation and survival of mammalian cells. Recently, Vega et al. proposed that exogenous prothymosin alpha can specifically increase the phosphorylation of eukaryotic elongation factor 2 (eEF-2) in extracts of NIH3T3 cells (Vega, F. V., Vidal, A., Hellman, U., Wernstedt, C., and Domínguez, F. (1998) J. Biol. Chem. 273, 10147-10152). Using similar lysates prepared by four methods (detergent lysis, Dounce homogenization, digitonin permeabilization, and sonication) and three preparations of prothymosin alpha, one of which was purified by gentle means (the native protein, and a histidine-tagged recombinant prothymosin alpha expressed either in bacteria or in COS cells), we failed to find a response. A reconstituted system composed of eEF-2, recombinant eEF-2 kinase, calmodulin, and calcium was also unaffected by prothymosin alpha. However, unlike our optimized buffer, Vega's system included a phosphatase inhibitor, 50 mM fluoride, which when evaluated in our laboratories severely reduced phosphorylation of all species. Under these conditions, any procedure that decreases the effective fluoride concentration will relieve the inhibition and appear to activate. Our data do not support a direct relationship between the function of prothymosin alpha and the phosphorylation of eEF-2.
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Affiliation(s)
- S A Enkemann
- Section on Genes and Gene Products, NCI, National Institutes of Health, Bethesda, Maryland 20892, USA
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32
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Costopoulou D, Leondiadis L, Czarnecki J, Ferderigos N, Ithakissios DS, Livaniou E, Evangelatos GP. Direct ELISA method for the specific determination of prothymosin alpha in human specimens. JOURNAL OF IMMUNOASSAY 1998; 19:295-316. [PMID: 9840299 DOI: 10.1080/01971529808005487] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
An enzyme linked immunosorbent assay, specific for prothymosin alpha (ProT alpha) was developed using an antibody against the synthetic C-terminal peptide ProT alpha[101-109] and isolated bovine ProT alpha for the preparation of standard solutions and immunoplates. Due to the antibody used, the ELISA developed was capable of fully discriminating between ProT alpha, the naturally occuring and partially homologous peptide parathymosin alpha (ParaT alpha) and the peptide thymosin alpha1 (T alpha1), whose sequence is identical to the [1-28] sequence of ProT alpha, and its in vivo occurrence is under question. Moreover, due to its improved sensitivity, the ELISA was capable of directly determining ProT alpha concentration in human serum and tissue extracts, without any pretreatment of the samples. ProT alpha levels were directly measured in sera obtained from 48 apparently healthy individuals and 27 patients with diagnosed breast cancer and found to range from 0.67 to 2.34 microg/ml (mean value 1.27 +/- 0.49 microg/ml) and from 0.47 to 1.74 microg/ml (mean value 1.02 +/- 0.29 microg/ml), respectively. ProT alpha levels were also measured in four breast tumor and adjacent normal breast tissue extracts and found to be elevated in the tumor extracts.
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Affiliation(s)
- D Costopoulou
- NCSR Demokritos, R.-R.P. Institute, Radioimmunochemistry Lab., Athens, Greece
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33
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Vega FV, Vidal A, Hellman U, Wernstedt C, Domínguez F. Prothymosin alpha stimulates Ca2+-dependent phosphorylation of elongation factor 2 in cellular extracts. J Biol Chem 1998; 273:10147-52. [PMID: 9553062 DOI: 10.1074/jbc.273.17.10147] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Prothymosin alpha (PTA) stimulates in a dose-dependent manner the phosphorylation of a 105-kDa protein (p105) in cell extracts from different cell types. Protein sequencing and immunological analysis indicated that this protein is elongation factor 2 (EF-2). We propose that calcium/calmodulin-dependent protein kinase III is responsible for the PTA-dependent EF-2 phosphorylation based on the following lines of evidence: (a) Ca2+ is required for the effect; (b) calmodulin enhances the reaction, and calmodulin inhibitors block the phosphorylation; and (c) no phosphorylation is seen in cell extracts depleted of calmodulin-binding proteins. To obtain a strong phosphorylated EF-2 band, we found it necessary to add PTA to cytosolic extracts from synchronized dividing cells in various phases of the cell cycle except in mitosis. Since PTA is a nuclear protein everywhere in the cell cycle except in mitosis, when it is found in the cytoplasm, we hypothesize that, if PTA activates EF-2 phosphorylation in vivo, as present data suggest, its presence in the cytoplasm during mitosis could explain why EF-2 phosphorylation is mainly restricted to that phase of the cell cycle. Moreover, other bands in addition to EF-2 were phosphorylated in a calmodulin- and PTA-dependent manner, and several of them (in a range between 50 and 60 kDa) have similar Mr to those that conform to the holoenzyme calcium/calmodulin dependent protein kinase II, suggesting that PTA could have a more general function modulating the activity of various Ca2+/CaM-dependent enzymes along the cell cycle.
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Affiliation(s)
- F V Vega
- Departamento de Fisiología, Facultad de Veterinaria, Lugo, 15705 Santiago de Compostela, Spain
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34
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Wang RH, Tao L, Trumbore MW, Berger SL. Turnover of the acyl phosphates of human and murine prothymosin alpha in vivo. J Biol Chem 1997; 272:26405-12. [PMID: 9334215 DOI: 10.1074/jbc.272.42.26405] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Prothymosin alpha is a small, highly acidic, abundant, nuclear, mammalian protein which is essential for cell growth. Our laboratory has recently shown that primate prothymosin alpha contains stoichiometric amounts of phosphate on the glutamyl groups of the protein and that in vitro the phosphate undergoes rapid hydrolysis or transfer to a nearby serine residue. Here an assay for the presence of acyl phosphates in vivo has been developed by measuring stable phosphoserine and phosphothreonine in vitro. The assay was used to determine the half-life of the acyl phosphates on prothymosin alpha in vivo by pulse-labeling HeLa cells with [32P]orthophosphate and chasing using three different techniques: permeabilization with digitonin to allow extracellular ATP to equilibrate with the intracellular pool; electroporation in the presence of ATP to reduce the specific activity of [32P]ATP by expansion of the pool; and incubation with inorganic phosphate. Regardless of the method, the phosphate turned over with a half-life of 75-90 min. The ability of cells to phosphorylate old prothymosin alpha molecules was established by demonstrating equivalent labeling of the protein with [32P]orthophosphate in the presence and absence of cycloheximide. The half-life of the acyl phosphates was also studied in resting and growing NIH3T3 cells, with measured values of 30-35 and 70 min, respectively. Our data suggest that the "activity" of prothymosin alpha involves the turnover of its acyl phosphates and that it participates in a function common to all nucleated mammalian cells regardless of whether they are quiescent or undergoing rapid proliferation. This is the first measurement of the stability of protein-bound acyl phosphates in vivo.
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Affiliation(s)
- R H Wang
- Section on Genes and Gene Products, NCI, National Institutes of Health, Bethesda, Maryland 20892, USA
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35
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Trumbore MW, Wang RH, Enkemann SA, Berger SL. Prothymosin alpha in vivo contains phosphorylated glutamic acid residues. J Biol Chem 1997; 272:26394-404. [PMID: 9334214 DOI: 10.1074/jbc.272.42.26394] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Human and monkey prothymosin alpha contain activated carbonyl groups on glutamic acid residues. Three lines of evidence indicate the existence of unusual phosphates. 1) Prothymosin alpha continued to be metabolically labeled with [32P]orthophosphoric acid despite a mutation at Ser1, the sole site of phosphate in purified bovine prothymosin alpha (Sburlati, A. R., De La Rosa, A., Batey, D. W., Kurys, G. L., Manrow, R. E., Pannell, L. K., Martin, B. M., Sheeley, D. M., and Berger, S. L. (1993) Biochemistry 32, 4587-4596). 2) Immediately upon cell lysis, the pH stability curves of metabolically labeled native [32P]prothymosin alpha or a [32P]histidine-tagged variant resembled the pH stability curve of acetyl phosphate. 3) After a brief incubation at pH 7, these curves changed from a pattern diagnostic for an acyl phosphate to that characteristic of a serine or threonine phosphate, an observation consistent with transfer of phosphate in vitro. Our data indicate that most of prothymosin alpha's phosphates are subject instantaneously to hydrolysis, based on the observation that greater than 90% of the phosphate initially found at pH 7 disappeared at the extremes of pH. Rapid loss of phosphate was not affected by the presence of phosphatase inhibitors including 50 mM sodium fluoride, 1 mM okadaic acid, and 0.5 mM calyculin A. The amount of phosphate missing could not be ascertained, but the trifling amount recovered on Ser or Thr depended heavily on conditions favoring the transient survival of labile phosphate. Further analysis using COS cells lysed in the presence of sodium borohydride showed that: 1) phosphate recovered on prothymosin alpha decreased 8-fold when lysates were treated with borohydride; 2) the reagent caused 4-8 glutamic acid residues/molecule to vanish; 3) using [3H]NaBH4, label was introduced into proline, a product derived from reductive cleavage of phosphoglutamate; and 4) [3H]proline was localized almost exclusively to a peptide with pronounced homology to the histone binding site of nucleoplasmin, a chromatin remodeling protein found in Xenopus laevis. Our data demonstrate that prothymosin alpha is energy-rich by virtue of stoichiometric amounts of glutamyl phosphate.
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Affiliation(s)
- M W Trumbore
- Section on Genes and Gene Products, NCI, National Institutes of Health, Bethesda, Maryland 20892, USA
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36
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Pérez-Estévez A, Díaz-Jullien C, Covelo G, Salgueiro MT, Freire M. A 180-kDa protein kinase seems to be responsible for the phosphorylation of prothymosin alpha observed in proliferating cells. J Biol Chem 1997; 272:10506-13. [PMID: 9099694 DOI: 10.1074/jbc.272.16.10506] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Prothymosin alpha (ProTalpha) is an acidic protein involved in cell proliferation. Its phosphorylation status is correlated with proliferative activity. Here we report the isolation and characterization of a ProTalpha-phosphorylating kinase (ProTalphaK) from mouse splenocytes that seems to be responsible for the in vivo phosphorylation of ProTalpha and that differs from other protein kinases reported to date. This enzyme, mainly located in the cytosol, has an molecular mass of 180 kDa and appears to be made up of two proteins of 64 and 60 kDa. Its activity was markedly enhanced by mitogenic activation of cells. The ProTalpha residues phosphorylated by the enzyme in vitro are a Thr at position 7 and another Thr at positions 12 or 13, both located within casein kinase 2 (CK-2) consensus motifs; these are the same residues as are phosphorylated in vivo. The new enzyme shows a number of clear structural and catalytic differences from CK-2. It phosphorylates histones H2B and H3, although with weaker activity than ProTalpha. An enzyme with the same characteristics was also found in other murine tissues and cell lines.
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Affiliation(s)
- A Pérez-Estévez
- Departamento de Bioquímica y Biología Molecular, Facultad de Biología, Universidad de Santiago, Santiago de Compostela, Spain
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37
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Abstract
Prothymosin alpha is an acidic nuclear protein that is expressed at high levels in a wide variety of cell types. Accumulating data correlate prothymosin expression with alterations in the proliferative state of cells. Some data indicates that prothymosin may actually be necessary, if not sufficient, for proliferation, and that prothymosin may function in a c-myc associated pathway. Prothymosin is highly conserved through evolution suggesting a key function, however, that function remains unknown.
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Affiliation(s)
- M R Smith
- Department of Medical Oncology, Fox Chase Cancer Center, Philadelphia, Pennsylvania 19111, USA
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38
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Barja P, Freire M. Prothymosin alpha and factors from calf thymic cells decrease expression of Thy 1.2 antigen among small thymocytes from C57BL/6 mice. Immunopharmacol Immunotoxicol 1994; 16:403-18. [PMID: 7798593 DOI: 10.3109/08923979409007101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
In this work we studied the effect of Prothymosin alpha (ProT alpha) and other thymic factors on the expression of Thy 1.2 antigen (a T-cell marker) and the activities of adenosine deaminase (ADA, E.C. 3.5.4.4), N-acetyl-beta-D-glucosaminidase (NABG, E.C. 3.2.1.30), beta-glucuronidase (BG, E.C. 3.1.1.1) and serine-esterase (SE, E.C. 3.4.21)., the levels of which change during the T-cell differentiation process among small thymocytes obtained from C57BL/6 mice. Incubation of small thymocytes in the presence of ProT alpha, Thymus Extracts (TE) or supernatants prepared from thymic stromal cells (TSCS) or thymocytes (TS) reduced the proportion of cells killed by anti-Thy 1.2 monoclonal antibodies but did not affect the enzymatic activities studied. This is the first evidence that ProT alpha affects Thy 1.2 expression in vitro.
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Affiliation(s)
- P Barja
- Departamento de Bioquímica y Biología Molecular, Facultad de Biología, Universidad de Santiago, Santiago de Compostela, Spain
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39
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Sburlati AR, De La Rosa A, Batey DW, Kurys GL, Manrow RE, Pannell LK, Martin BM, Sheeley DM, Berger SL. Phosphorylation of human and bovine prothymosin alpha in vivo. Biochemistry 1993; 32:4587-96. [PMID: 8485135 DOI: 10.1021/bi00068a015] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Prothymosin alpha is post-translationally modified. When human myeloma cells were metabolically labeled with [32P]orthophosphoric acid, they synthesized [32P]prothymosin alpha. The incorporated radioactivity was resistant to DNase and RNases A, T1, and T2, but could be completely removed by alkaline phosphatase. No evidence was found for an RNA adduct as postulated by Vartapetian et al. [Vartapetian, A., Makarova, T., Koonin, E. V., Agol, V. I., & Bogdanov, A. (1988) FEBS Lett. 232, 35-38]. Thin-layer electrophoresis of partially hydrolyzed [32P]prothymosin alpha indicated that serine residues were phosphorylated. Analysis of peptides derived from bovine prothymosin alpha and human [32P]prothymosin alpha by treatment with endoproteinase Lys-C revealed that the amino-terminal 14-mer, with serine residues at positions 1, 8, and 9, was phosphorylated at a single position. Approximately 2% of the peptide in each case contained phosphate. Further digestion of the phosphopeptide with Asp-N followed by C18 reversed-phase column chromatography produced two peptides: a phosphate-free 9-mer containing amino acids 6-14 and a labeled peptide migrating slightly faster than the N-terminal 5-mer derived from the unmodified 14-mer. Positive identification of the phosphorylated amino acid was obtained by colliding the 14-residue phosphopeptide with helium in the mass spectrometer and finding phosphate only in a nested set of phosphorylated fragments composed of the first three, four, and five amino acids. The results prove that prothymosin alpha contains N-terminal acetylserine phosphate. In a synchronized population of human myeloma cells, phosphorylation occurred throughout the cell cycle. Furthermore, prothymosin alpha appeared to be stable, with a half-life slightly shorter than the generation time. Although prothymosin alpha is known to be essential for cell division, the constancy of both the amount of the protein and the degree of its phosphorylation suggests that prothymosin alpha does not directly govern mitosis.
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Affiliation(s)
- A R Sburlati
- Section on Genes and Gene Products, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892
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40
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Barcia M, Castro J, Jullien C, Freire M. Prothymosin alpha is phosphorylated in proliferating stimulated cells. J Biol Chem 1993. [DOI: 10.1016/s0021-9258(18)53453-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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41
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Szabo P, Panneerselvam C, Clinton M, Frangou-Lazaridis M, Weksler D, Whittington E, Macera MJ, Grzeschik KH, Selvakumar A, Horecker BL. Prothymosin alpha gene in humans: organization of its promoter region and localization to chromosome 2. Hum Genet 1993; 90:629-34. [PMID: 7916742 DOI: 10.1007/bf00202480] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
A genomic clone encoding prothymosin alpha (gene symbol: PTMA), a nuclear-targeted protein associated with cell proliferation, was isolated and the 5'-regulatory region subcloned and sequenced. Because of previously reported discrepancies between several cDNA clones and a genomic clone for prothymosin alpha, we determined the sequence of the first exon and of a 1.7-kb region 5' to the first exon. The sequence of the genomic clone reported here corresponds to the published cDNA sequences, suggesting that the previously noted discrepancies may be due to genetic polymorphism in this region. In addition, our sequence data extend the known 5'-upstream sequence by an additional 1.5 kb allowing the identification of numerous, potential cis-acting regulatory sites. This 5'-flanking cloned probe permitted us to localize the prothymosin gene to chromosome 2 in humans.
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Affiliation(s)
- P Szabo
- Department of Medicine, Cornell University Medical College, New York, NY 10021
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42
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Vartapetian A, Chichkova N, Lyakhov I, Makarova T, Evstafieva A, Bogdanov A. Segments of Escherichia coli genome similar to the exons of human prothymosin alpha gene. FEBS Lett 1992; 313:95-7. [PMID: 1426289 DOI: 10.1016/0014-5793(92)81420-q] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Identification of the putative prothymosin alpha homolog in Escherichia coli cells prompted the search for a prothymosin alpha-coding gene in the E. coli genome. A set of interspersed DNA segments was identified, which match various parts of the human prothymosin alpha molecule. Their location in the E. coli genome and high degree of similarity with the appropriate regions of the human prothymosin alpha gene suggest that some kind of trans-splicing should exist in E. coli, which could be responsible for bringing these putative bacterial prothymosin alpha-coding exons together.
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Affiliation(s)
- A Vartapetian
- Belozersky Institute of Physico-Chemical Biology, Moscow State University, Russia
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43
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Barcia MG, Castro JM, Jullien CD, González CG, Freire M. Prothymosin alpha is phosphorylated by casein kinase-2. FEBS Lett 1992; 312:152-6. [PMID: 1426245 DOI: 10.1016/0014-5793(92)80924-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Prothymosin alpha (ProT alpha) is a 12.5 kDa acidic polypeptide that is considered to have a nuclear function related to cell proliferation. Inspection of its amino acid sequence revealed the presence of sequences that may serve as targets for phosphorylation by casein kinase-2 (CK-2). ProT alpha isolated from calf thymocytes was phosphorylated in vitro by CK-2. The phosphorylation sites are Ser and Thr residues located among the first 14 amino acid residues in the ProT alpha sequence. Another site that is theoretically suitable for phosphorylation by CK-2, at the C-terminus of the polypeptide, is not, in fact, phosphorylated. Thymosin alpha 1 (T alpha 1), a peptide whose sequence corresponds to the first 28 amino acids of ProT alpha, is also phosphorylated by CK-2 at the same phosphorylation sites as ProT alpha. In cultured splenic lymphocytes ProT alpha was phosphorylated at Thr residues located at positions 7, 12 and/or 13. Based on these observations we conclude that CK-2, or another cellular kinase with similar sequence specificity, is responsible for phosphorylation of ProT alpha in vivo.
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Affiliation(s)
- M G Barcia
- Departamento de Bioquímica e Bioloxía Molecular, Facultade de Bioloxía, Universidade de Santiago, Galicia, Spain
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44
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Sanders MC, Goldstein AL, Wang YL. Thymosin beta 4 (Fx peptide) is a potent regulator of actin polymerization in living cells. Proc Natl Acad Sci U S A 1992; 89:4678-82. [PMID: 1584803 PMCID: PMC49146 DOI: 10.1073/pnas.89.10.4678] [Citation(s) in RCA: 115] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Thymosin beta 4 (beta 4) is a 5-kDa polypeptide originally identified in calf thymus. Although numerous activities have been attributed to beta 4, its physiological role remains elusive. Recently, beta 4 was found to bind actin in human platelet extracts and to inhibit actin polymerization in vitro, raising the possibility that it may be a physiological regulator of actin assembly. To examine this potential function, we have increased the cellular beta 4 concentration by microinjecting synthetic beta 4 into living epithelial cells and fibroblasts. The injection induced a diminution of stress fibers and a dose-dependent depolymerization of actin filaments as indicated by quantitative image analysis of phalloidin binding. Our results show that beta 4 is a potent regulator of actin assembly in living cells.
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Affiliation(s)
- M C Sanders
- Cell Biology Group, Worcester Foundation for Experimental Biology, Shrewsbury, MA 01545
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45
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Tsitsiloni OE, Yialouris PP, Echner H, Voelter W, Haritos AA. Evidence for the extranuclear localization of thymosins in thymus. EXPERIENTIA 1992; 48:398-402. [PMID: 1582498 DOI: 10.1007/bf01923441] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
A new radioimmunoassay has been developed for thymosin beta 4 by generating rabbit polyclonal antibodies against the synthetic N-terminal peptide fragment 1-15 coupled to KLH. The synthetic analogue [Tyr12]-thymosin beta 4 (1-15) was used as tracer. This radioimmunoassay, with a useful range of 10-1000 pmoles, showed cross-reactivity with the second homologous beta-thymosin of man and rat (thymosin beta 10) but not of calf (thymosin beta 9). This radioimmunoassay, together with an improved radioimmunoassay for the N-terminus of parathymosin alpha, was employed for the measurement of the levels of thymosin beta 4 and parathymosin alpha in nuclear and extranuclear extracts of calf thymus. The bulk of these polypeptides was found in the extranuclear material whereas only traces were observed in the nuclear environment, which indicates the extranuclear localisation of alpha- and beta-thymosins.
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46
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Frillingos S, Tsolas O. Age- and sex-related differences in the content of prothymosin alpha in rat tissues. EXPERIENTIA 1992; 48:236-9. [PMID: 1547851 DOI: 10.1007/bf01930463] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Differences in the tissue content of prothymosin alpha during the early postnatal development of male and female rats are reported. Thymus and spleen have been found to contain significantly higher amounts of prothymosin alpha in the newborn and prepubertal animals, as compared to adults, whereas liver has been found to contain low levels of prothymosin alpha throughout development. These findings indicate a functional association of prothymosin alpha with the proliferating lymphoid tissues of the young rat.
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Affiliation(s)
- S Frillingos
- Laboratory of Biological Chemistry, University of Ioannina Medical School, Greece
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47
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Papanastasiou M, Baxevanis CN, Papamichail M. Promotion of murine antitumor activity by prothymosin alpha treatment: I. Induction of tumoricidal peritoneal cells producing high levels of tumour necrosis factor alpha. Cancer Immunol Immunother 1992; 35:145-50. [PMID: 1596938 PMCID: PMC11038346 DOI: 10.1007/bf01741862] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/1991] [Accepted: 01/15/1992] [Indexed: 12/27/2022]
Abstract
The effect of prothymosin alpha (ProT alpha) on the survival of DBA/2 mice inoculated with syngeneic tumour cells was studied. DBA/2 mice inoculated intraperitoneally (i.p.) with 2 x 10(5) syngeneic leukaemic L1210 cells developed ascites within 8-12 days and died 10-14 days later. Treatment with ProT alpha consistently inhibited the development of ascites in 20% of the treated animals and prolonged the survival of 40%-60% of the animals up to 70 days. The most effective treatment schedule of ProT alpha was 300 ng/mouse given i.p. at 2-day intervals for 3 weeks followed by a rest period of 7 days, prior to tumour cell inoculation. Peritoneal exudate (PE) cells collected from mice treated with the optimal dose of ProT alpha produced, in the absence of exogenous stimulus, six- to eightfold higher levels of tumour necrosis factor alpha (TNF alpha) than PE cells from control mice. Furthermore these cells exhibited cytotoxic activity against several tumour cell lines including the syngeneic L1210, the TNF-insensitive P815 mastocytoma, the human MOLT-4 lymphoblastic leukaemia, as well as the murine TNF-sensitive L929 fibroblast cell line. Kinetic studies revealed that both production of TNF alpha and tumoricidal activity peaked 7 days after the last injection of ProT alpha and were maintained at high levels over a period of 1 month. Injections with 150 ng ProT alpha slightly improved the survival of mice whereas higher (500 ng and 1000 ng) doses of ProT alpha and a wide range of thymosin alpha 1 doses remained without any effect. PE cells collected from these mice produced extremely low levels of TNF alpha and exhibited negligible tumoricidal activity. Our data demonstrate that ProT alpha has a protective effect in vivo against the growth of adoptively transferred tumour cells and suggest that this effect is, at least in part, mediated by ProT alpha-activated PE cells. These cells were demonstrated to produce high levels of TNF alpha in vitro and to exhibit activity against both TNF-sensitive and TNF-resistant cell lines.
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Affiliation(s)
- M Papanastasiou
- Department of Immunology, Hellenic Anticancer Institute, Athens, Greece
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48
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Frillingos S, Frangou-Lazaridis M, Seferiadis K, Hulmes JD, Pan YC, Tsolas O. Isolation and partial sequence of goat spleen prothymosin alpha. Mol Cell Biochem 1991; 108:85-94. [PMID: 1770947 DOI: 10.1007/bf00239545] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Goat prothymosin alpha, a highly acidic polypeptide of pI3.5, 109 amino acid residues, has been isolated from lymphoid and non-lymphoid tissues of young female goats. Unlike rat, murine and porcine prothymosins alpha, goat prothymosin alpha appears at a higher concentration in the spleen compared with the thymus. The sequence of segments of the polypeptide involving known mutations has been determined, by automatic sequencing of its tryptic peptide fragments. The acidic amino acid-rich segment in the middle of the molecule, including residues 49-83, has not been sequenced. Goat prothymosin alpha closely resembles bovine prothymosin alpha, with only one substitution, proline for alanine at position 85. It also resembles human prothymosin alpha, with only three substitutions. It differs more significantly from rat and murine prothymosins alpha, by two deletions and three substitutions. The results show the highly conserved nature of the molecule, with substitutions at given positions only.
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Affiliation(s)
- S Frillingos
- Laboratory of Biological Chemistry, University of Ioannina Medical School, Greece
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49
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Marić D, Veljić J, Ranin J, Janković BD. In vivo effect of prothymosin-alpha 1 on humoral and cell-mediated immune responses in the young rat. Int J Neurosci 1991; 59:135-42. [PMID: 1837789 DOI: 10.3109/00207459108985456] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
There is a large body of evidence for the role of thymosin peptides in immunogenesis and immunity. In this paper we report on the influence of prothymosin alpha 1 (ProT-alpha 1), a hormone-like peptide derived from the calf thymus, on humoral and cellular immune reactions in the rat. Young adults received intraperitoneal injections of ProT-alpha 1 in the periods before and after immunization with cellular and soluble antigens. ProT-alpha-treatment produced a dose-dependent increase of both humoral and cell-mediated immune responses. The thymus weight increased but not that of spleen. Treatment of nonimmunized rats with this polypeptide significantly elevated the number of CD4+ and decreased the number of CD8+ cells in the peripheral blood. The results suggest a potent immunostimulatory activity of ProT-alpha 1 and imply direct action of this polypeptide on T lymphocytes.
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Affiliation(s)
- D Marić
- Immunology Research Center, Yugoslavia
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50
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