1
|
Sugiyama K, Kawaguchi A, Okuwaki M, Nagata K. pp32 and APRIL are host cell-derived regulators of influenza virus RNA synthesis from cRNA. eLife 2015; 4. [PMID: 26512887 PMCID: PMC4718810 DOI: 10.7554/elife.08939] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2015] [Accepted: 10/20/2015] [Indexed: 12/02/2022] Open
Abstract
Replication of influenza viral genomic RNA (vRNA) is catalyzed by viral RNA-dependent RNA polymerase (vRdRP). Complementary RNA (cRNA) is first copied from vRNA, and progeny vRNAs are then amplified from the cRNA. Although vRdRP and viral RNA are minimal requirements, efficient cell-free replication could not be reproduced using only these viral factors. Using a biochemical complementation assay system, we found a novel activity in the nuclear extracts of uninfected cells, designated IREF-2, that allows robust unprimed vRNA synthesis from a cRNA template. IREF-2 was shown to consist of host-derived proteins, pp32 and APRIL. IREF-2 interacts with a free form of vRdRP and preferentially upregulates vRNA synthesis rather than cRNA synthesis. Knockdown experiments indicated that IREF-2 is involved in in vivo viral replication. On the basis of these results and those of previous studies, a plausible role(s) for IREF-2 during the initiation processes of vRNA replication is discussed. DOI:http://dx.doi.org/10.7554/eLife.08939.001 The influenza or “flu” virus infects millions of people each year, with young children and elderly individuals most vulnerable to infection. The influenza virus stores its genetic material in the form of segments of single-stranded viral RNA. After the virus infects a cell, it replicates this genetic material in a two-part process. First, an enzyme made by the virus – called RNA polymerase – uses the viral genomic RNA as a template to form a “complementary” RNA strand (called cRNA). This cRNA molecule is then itself used as a template to make more viral genomic RNA strands, which can go on to form new viruses. Exactly how viral genomic RNA is made from cRNA is poorly understood, although previous research had suggested that this process may also involve proteins belonging to the invaded host cell. However, these host proteins had not been identified. By mixing virus particles with extracts from uninfected human cells, Sugiyama et al. have now found that two host proteins called pp32 and APRIL help viral genomic RNA to form from a cRNA template. Both of these proteins directly interact with the viral RNA polymerase. Sugiyama et al. then reduced the amounts of pp32 and APRIL in human cells that were infected with the influenza virus. Much less viral genomic RNA – and so fewer new virus particles – formed in these cells than in normal cells. Further work is now needed to understand how the pp32 and APRIL proteins interact with viral RNA polymerase. This could eventually lead to the development of new treatments for influenza. DOI:http://dx.doi.org/10.7554/eLife.08939.002
Collapse
Affiliation(s)
- Kenji Sugiyama
- Department of Infection Biology, Faculty of Medicine, University of Tsukuba, Tsukuba, Japan
| | - Atsushi Kawaguchi
- Department of Infection Biology, Faculty of Medicine, University of Tsukuba, Tsukuba, Japan
| | - Mitsuru Okuwaki
- Department of Infection Biology, Faculty of Medicine, University of Tsukuba, Tsukuba, Japan
| | - Kyosuke Nagata
- Department of Infection Biology, Faculty of Medicine, University of Tsukuba, Tsukuba, Japan
| |
Collapse
|
2
|
Reilly PT, Yu Y, Hamiche A, Wang L. Cracking the ANP32 whips: important functions, unequal requirement, and hints at disease implications. Bioessays 2014; 36:1062-71. [PMID: 25156960 PMCID: PMC4270211 DOI: 10.1002/bies.201400058] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The acidic (leucine-rich) nuclear phosphoprotein 32 kDa (ANP32) family is composed of small, evolutionarily conserved proteins characterized by an N-terminal leucine-rich repeat domain and a C-terminal low-complexity acidic region. The mammalian family members (ANP32A, ANP32B, and ANP32E) are ascribed physiologically diverse functions including chromatin modification and remodelling, apoptotic caspase modulation, protein phosphatase inhibition, as well as regulation of intracellular transport. In addition to reviewing the widespread literature on the topic, we present a concept of the ANP32s as having a whip-like structure. We also present hypotheses that ANP32C and other intronless sequences should not currently be considered bona fide family members, that their disparate necessity in development may be due to compensatory mechanisms, that their contrasting roles in cancer are likely context-dependent, along with an underlying hypothesis that ANP32s represent an important node of physiological regulation by virtue of their diverse biochemical activities.
Collapse
Affiliation(s)
- Patrick T Reilly
- Laboratory of Inflammation Biology, National Cancer Centre Singapore, Singapore, Singapore
| | | | | | | |
Collapse
|
3
|
Buddaseth S, Göttmann W, Blasczyk R, Huyton T. Overexpression of the pp32r1 (ANP32C) oncogene or its functional mutant pp32r1Y140H confers enhanced resistance to FTY720 (Finguimod). Cancer Biol Ther 2013; 15:289-96. [PMID: 24335183 DOI: 10.4161/cbt.27307] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
pp32r1 (ANP32C) is oncogenic and has been shown to be overexpressed in tumors of the breast, prostate, and pancreas. In this work we show that pp32 family proteins are able to bind to the sphingosine analog FTY720 (Finguimod). Molecular docking studies highlight that a conserved residue F136 is likely to be a key determinant of the FTY720 binding site on the pp32 leucine-rich repeat domain. Transduction of the renal carcinoma cell line ACHN or cervical cancer cell line HeLa with lentivirus expressing the oncogenic family member pp32r1 or a pp32r1Y140H functional mutant illustrated an enhanced resistance to FTY720 induced apoptosis. These findings highlight that certain cancers overexpressing pp32r1 or pp32r1 mutants are likely to demonstrate enhanced resistance to FTY720 treatment.
Collapse
Affiliation(s)
- Salma Buddaseth
- Institute for Transfusion Medicine; Hannover Medical School; Hannover, Germany
| | - Wiebke Göttmann
- Institute for Transfusion Medicine; Hannover Medical School; Hannover, Germany
| | - Rainer Blasczyk
- Institute for Transfusion Medicine; Hannover Medical School; Hannover, Germany
| | - Trevor Huyton
- Institute for Transfusion Medicine; Hannover Medical School; Hannover, Germany
| |
Collapse
|
4
|
Li C, Ruan HQ, Liu YS, Xu MJ, Dai J, Sheng QH, Tan YX, Yao ZZ, Wang HY, Wu JR, Zeng R. Quantitative Proteomics Reveal up-regulated Protein Expression of the SET Complex Associated with Hepatocellular Carcinoma. J Proteome Res 2011; 11:871-85. [DOI: 10.1021/pr2006999] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Chen Li
- Key Laboratory of Systems Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China
| | - Hong-Qiang Ruan
- Key Laboratory of Systems Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China
| | - Yan-Sheng Liu
- Key Laboratory of Systems Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China
| | - Meng-Jie Xu
- Key Laboratory of Systems Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China
| | - Jie Dai
- Key Laboratory of Systems Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China
| | - Quan-Hu Sheng
- Key Laboratory of Systems Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China
| | - Ye-Xiong Tan
- Eastern Hepatobiliary Surgery Hospital, No. 225, Changhai Road, Shanghai 200438, China
| | - Zhen-Zhen Yao
- Department of Biochemistry & Molecular Biology, Second Military Medical University, Shanghai 200438, China
| | - Hong-Yang Wang
- Eastern Hepatobiliary Surgery Hospital, No. 225, Changhai Road, Shanghai 200438, China
| | - Jia-Rui Wu
- Key Laboratory of Systems Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China
| | - Rong Zeng
- Key Laboratory of Systems Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China
| |
Collapse
|
5
|
Williams TK, Costantino CL, Bildzukewicz NA, Richards NG, Rittenhouse DW, Einstein L, Cozzitorto JA, Keen JC, Dasgupta A, Gorospe M, Gonye GE, Yeo CJ, Witkiewicz AK, Brody JR. pp32 (ANP32A) expression inhibits pancreatic cancer cell growth and induces gemcitabine resistance by disrupting HuR binding to mRNAs. PLoS One 2010; 5:e15455. [PMID: 21152064 PMCID: PMC2994932 DOI: 10.1371/journal.pone.0015455] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2010] [Accepted: 09/26/2010] [Indexed: 01/12/2023] Open
Abstract
The expression of protein phosphatase 32 (PP32, ANP32A) is low in poorly differentiated pancreatic cancers and is linked to the levels of HuR (ELAV1), a predictive marker for gemcitabine response. In pancreatic cancer cells, exogenous overexpression of pp32 inhibited cell growth, supporting its long-recognized role as a tumor suppressor in pancreatic cancer. In chemotherapeutic sensitivity screening assays, cells overexpressing pp32 were selectively resistant to the nucleoside analogs gemcitabine and cytarabine (ARA-C), but were sensitized to 5-fluorouracil; conversely, silencing pp32 in pancreatic cancer cells enhanced gemcitabine sensitivity. The cytoplasmic levels of pp32 increased after cancer cells are treated with certain stressors, including gemcitabine. pp32 overexpression reduced the association of HuR with the mRNA encoding the gemcitabine-metabolizing enzyme deoxycytidine kinase (dCK), causing a significant reduction in dCK protein levels. Similarly, ectopic pp32 expression caused a reduction in HuR binding of mRNAs encoding tumor-promoting proteins (e.g., VEGF and HuR), while silencing pp32 dramatically enhanced the binding of these mRNA targets. Low pp32 nuclear expression correlated with high-grade tumors and the presence of lymph node metastasis, as compared to patients' tumors with high nuclear pp32 expression. Although pp32 expression levels did not enhance the predictive power of cytoplasmic HuR status, nuclear pp32 levels and cytoplasmic HuR levels associated significantly in patient samples. Thus, we provide novel evidence that the tumor suppressor function of pp32 can be attributed to its ability to disrupt HuR binding to target mRNAs encoding key proteins for cancer cell survival and drug efficacy.
Collapse
Affiliation(s)
- Timothy K. Williams
- Department of Surgery, Jefferson Pancreas, Biliary and Related Cancer Center, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
| | - Christina L. Costantino
- Department of Surgery, Jefferson Pancreas, Biliary and Related Cancer Center, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
| | - Nikolai A. Bildzukewicz
- Department of Surgery, Jefferson Pancreas, Biliary and Related Cancer Center, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
| | - Nathan G. Richards
- Department of Surgery, Jefferson Pancreas, Biliary and Related Cancer Center, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
| | - David W. Rittenhouse
- Department of Surgery, Jefferson Pancreas, Biliary and Related Cancer Center, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
| | - Lisa Einstein
- Department of Surgery, Jefferson Pancreas, Biliary and Related Cancer Center, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
| | - Joseph A. Cozzitorto
- Department of Surgery, Jefferson Pancreas, Biliary and Related Cancer Center, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
| | - Judith C. Keen
- Robert Wood Johnson Medical School, University of Medicine and Dentistry of New Jersey, Camden, New Jersey, United States of America
| | - Abhijit Dasgupta
- Department of Pathology, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
- Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
| | - Myriam Gorospe
- Laboratory of Cellular and Molecular Biology, National Institute on Aging-Intramural Research Program, National Institutes of Health, Baltimore, Maryland, United States of America
| | - Gregory E. Gonye
- Department of Pathology, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
| | - Charles J. Yeo
- Department of Surgery, Jefferson Pancreas, Biliary and Related Cancer Center, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
- Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
| | - Agnieszka K. Witkiewicz
- Department of Surgery, Jefferson Pancreas, Biliary and Related Cancer Center, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
- Department of Pathology, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
- Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
| | - Jonathan R. Brody
- Department of Surgery, Jefferson Pancreas, Biliary and Related Cancer Center, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
- Department of Pathology, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
- Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
- * E-mail:
| |
Collapse
|
6
|
Involvement of Hepatopoietin Cn in the development of human hepatocellular carcinoma. Clin Exp Metastasis 2010; 27:571-80. [DOI: 10.1007/s10585-010-9346-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2010] [Accepted: 07/15/2010] [Indexed: 01/12/2023]
|
7
|
Characterization and binding affinities of SmLANP: a new Schistosoma mansoni member of the ANP32 family of regulatory proteins. Mol Biochem Parasitol 2009; 165:95-102. [PMID: 19428656 DOI: 10.1016/j.molbiopara.2009.01.009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2008] [Revised: 01/15/2009] [Accepted: 01/16/2009] [Indexed: 11/20/2022]
Abstract
Members of the leucine-rich repeat protein family are involved in diverse functions including protein phosphatase 2-inhibition, cell cycle regulation, gene regulation and signalling pathways. A novel Schistosoma mansoni gene, called SmLANP, presenting homology to various genes coding for proteins that belong to the super family of leucine-rich repeat proteins, was characterized here. SmLANP was 1184bp in length as determined from cDNA and genomic sequences and encoded a 296 amino acid open reading frame that spanning from 6 to 894bp. The predicted amino acid sequence had a calculated molecular weight of 32kDa. Analysis of the predicted sequence indicated the presence of 3 leucine-rich domains (LRR) located in the N-terminal region and an aspartic acid rich region in the C-terminal end. SmLANP transcript is expressed in all stages of the S. mansoni life cycle analyzed, exhibiting the highest expression level in males. The SmLANP protein was expressed in a GST expression system and antibodies raised in mice against the recombinant protein. By immunolocalization assay, using adult worms, it was shown that the protein is mainly present in the cell nucleus through the whole body and strongly expressed along the tegument cell body nuclei of adult worms. As members of this family are usually involved in protein-protein interaction, a yeast two hybrid assay was conducted to identify putative binding partners for SmLANP. Thirty-six possible partners were identified, and a protein ATP synthase subunit alpha was confirmed by pull down assays, as a binding partner of the SmLANP protein.
Collapse
|
8
|
HuR interacts with human immunodeficiency virus type 1 reverse transcriptase, and modulates reverse transcription in infected cells. Retrovirology 2008; 5:47. [PMID: 18544151 PMCID: PMC2441633 DOI: 10.1186/1742-4690-5-47] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2008] [Accepted: 06/10/2008] [Indexed: 11/10/2022] Open
Abstract
Reverse transcription of the genetic material of human immunodeficiency virus type 1 (HIV-1) is a critical step in the replication cycle of this virus. This process, catalyzed by reverse transcriptase (RT), is well characterized at the biochemical level. However, in infected cells, reverse transcription occurs in a multiprotein complex - the reverse transcription complex (RTC) - consisting of viral genomic RNA associated with viral proteins (including RT) and, presumably, as yet uncharacterized cellular proteins. Very little is known about the cellular proteins interacting with the RTC, and with reverse transcriptase in particular. We report here that HIV-1 reverse transcription is affected by the levels of a nucleocytoplasmic shuttling protein - the RNA-binding protein HuR. A direct protein-protein interaction between RT and HuR was observed in a yeast two-hybrid screen and confirmed in vitro by homogenous time-resolved fluorescence (HTRF). We mapped the domain interacting with HuR to the RNAse H domain of RT, and the binding domain for RT to the C-terminus of HuR, partially overlapping the third RRM RNA-binding domain of HuR. HuR silencing with specific siRNAs greatly impaired early and late steps of reverse transcription, significantly inhibiting HIV-1 infection. Moreover, by mutagenesis and immunoprecipitation studies, we could not detect the binding of HuR to the viral RNA. These results suggest that HuR may be involved in and may modulate the reverse transcription reaction of HIV-1, by an as yet unknown mechanism involving a protein-protein interaction with HIV-1 RT.
Collapse
|
9
|
|
10
|
Cui CP, Zhang DJ, Shi BX, Du SJ, Wu DL, Wei P, Zhong GS, Guo ZK, Liu Y, Wang LS, Wu CT. Isolation and functional identification of a novel human hepatic growth factor: hepatopoietin Cn. Hepatology 2008; 47:986-95. [PMID: 18306214 DOI: 10.1002/hep.22126] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
UNLABELLED Hepatic stimulating substance (HSS) was first isolated from weanling rat liver in 1975 and found to stimulate hepatic DNA synthesis both in vitro and in vivo. Since then, mammalian and human HSS have been investigated for their potential to treat hepatic diseases. However, the essential nature in composition and structure of HSS remain puzzling because HSS has not been completely purified. Heating, ethanol precipitation, and ion-exchange chromatographies had been carried out to isolate the protein with specific stimulating activity from newborn calf liver, and [(3)H]thymidine deoxyribose (TdR)/bromodeoxyuridine (BrdU) incorporation and carboxyfluorescein diacetate succinimidyl ester (CFSE)-based proliferation assay to determine the bioactivity in vitro and in vivo. We report the purification of a novel 30-kDa protein from a crude extract of calf liver HSS. This protein is a member of the leucine-rich acidic nuclear protein family (LANP) and has been named hepatopoietin Cn (HPPCn). Studies of partially hepatectomized (PH) mice show that levels of HPPCn messenger RNA (mRNA) increase after liver injury. Furthermore, the recombinant human protein (rhHPPCn) was shown to stimulate hepatic DNA synthesis and activate signaling pathways involved in hepatocyte proliferation in vitro and in vivo. CONCLUSION HPPCn is a novel hepatic growth factor that plays a role in liver regeneration.
Collapse
Affiliation(s)
- Chun-Ping Cui
- Department of Experimental Hematology, Beijing Institute of Radiation Medicine, People's Republic of China
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
11
|
Brody JR, Witkiewicz A, Williams TK, Kadkol SS, Cozzitorto J, Durkan B, Pasternack GR, Yeo CJ. Reduction of pp32 expression in poorly differentiated pancreatic ductal adenocarcinomas and intraductal papillary mucinous neoplasms with moderate dysplasia. Mod Pathol 2007; 20:1238-44. [PMID: 17906614 DOI: 10.1038/modpathol.3800974] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Nuclear phosphoprotein 32 (pp32) inhibits K-ras induced transformation in experimental models. pp32 mRNA expression correlates with differentiation status in breast and prostate cancers. In this study, we evaluated pp32 protein expression in relation to the differentiation status of pancreatic ductal adenocarcinomas and precursor lesions of the pancreatic cancers. pp32 expression showed strong nuclear staining in normal pancreatic acini and ducts. The intensity of this staining was maintained in pancreatic intraepithelial neoplasia, intraductal papillary mucinous neoplasms with mild dysplasia, well-differentiated adenocarcinomas, and in a subset of moderately differentiated adenocarcinomas. pp32 staining was absent or reduced in poorly differentiated tumors and in intraductal papillary mucinous neoplasms with moderate dysplasia. We validated pp32 expression by a second technique, immunoblot analysis of lysates from resected pancreatic ductal adenocarcinomas and pancreatic cancer cell lines. The well-differentiated pancreatic cancer cell line HPAC expressed high amounts of pp32, as compared to the poorly differentiated pancreatic cancer cell lines MiaPaCa2, Pl19, and Pl21 cells. Artificial introduction of pp32 expression into a poorly differentiated cell line, MiaPaCa2, caused an increase in G1 arrest compared to control cells. On the basis of this study and previous functional work that shows pp32 can inhibit K-ras transformation, we propose that reduction in pp32 expression levels may be a critical event in the progression of pancreatic tumorigenesis in an aggressive subset of pancreatic ductal adenocarcinomas.
Collapse
Affiliation(s)
- Jonathan R Brody
- Department of Surgery, Thomas Jefferson University, 1015 Walnut Street, Philadelphia, PA 19107, USA.
| | | | | | | | | | | | | | | |
Collapse
|
12
|
Huyton T, Wolberger C. The crystal structure of the tumor suppressor protein pp32 (Anp32a): structural insights into Anp32 family of proteins. Protein Sci 2007; 16:1308-15. [PMID: 17567741 PMCID: PMC2206682 DOI: 10.1110/ps.072803507] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The tumor suppressor protein pp32 is highly overexpressed in many cancers of the breast and prostate, and has also been implicated in the neurodegenerative disease spinocerebellar ataxias type 1 (SCA1). Pp32 is a multifunctional protein that is involved in the regulation of transcription, apoptosis, phosphorylation, and cell cycle progression, the latter through its association with the hyperphosphorylated form of the retinoblastoma tumor suppressor. We have determined the structure of an N-terminal pp32 fragment comprising a capped leucine-rich repeat (LRR) domain, which provides insight into the structural and biochemical properties of the pp32 (Anp32) family of proteins.
Collapse
Affiliation(s)
- Trevor Huyton
- Department of Biophysics and Biophysical Chemistry, Howard Hughes Medical Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21205-2185, USA
| | | |
Collapse
|
13
|
Spector DJ. Default assembly of early adenovirus chromatin. Virology 2007; 359:116-25. [PMID: 17034827 DOI: 10.1016/j.virol.2006.09.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2006] [Revised: 08/23/2006] [Accepted: 09/06/2006] [Indexed: 11/17/2022]
Abstract
In adenovirus particles, the viral nucleoprotein is organized into a highly compacted core structure. Upon delivery to the nucleus, the viral nucleoprotein is very likely to be remodeled to a form accessible to the transcription and replication machinery. Viral protein VII binds to intra-nuclear viral DNA, as do at least two cellular proteins, SET/TAF-Ibeta and pp32, components of a chromatin assembly complex that is implicated in template remodeling. We showed previously that viral DNA-protein complexes released from infecting particles were sensitive to shearing after cross-linking with formaldehyde, presumably after transport of the genome into the nucleus. We report here the application of equilibrium-density gradient centrifugation to the analysis of the fate of these complexes. Most of the incoming protein VII was recovered in a form that was not cross-linked to viral DNA. This release of protein VII, as well as the binding of SET/TAF-Ibeta and cellular transcription factors to the viral chromatin, did not require de novo viral gene expression. The distinct density profiles of viral DNA complexes containing protein VII, compared to those containing SET/TAF-Ibeta or transcription factors, were consistent with the notion that the assembly of early viral chromatin requires both the association of SET/TAF-1beta and the release of protein VII.
Collapse
Affiliation(s)
- David J Spector
- Department of Microbiology and Immunology, Pennsylvania State University College of Hershey, PA 17033, USA.
| |
Collapse
|
14
|
Pegoraro G, Marcello A, Myers MP, Giacca M. Regulation of adeno-associated virus DNA replication by the cellular TAF-I/set complex. J Virol 2006; 80:6855-64. [PMID: 16809291 PMCID: PMC1489034 DOI: 10.1128/jvi.00383-06] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
The Rep proteins of the adeno-associated virus (AAV) are required for viral replication in the presence of adenovirus helper functions and as yet poorly characterized cellular factors. In an attempt to identify such factors, we purified Flag-Rep68-interacting proteins from human cell lysates. Several polypeptides were identified by mass spectrometry, among which was ANP32B, a member of the acidic nuclear protein 32 family which takes part in the formation of the template-activating factor I/Set oncoprotein (TAF-I/Set) complex. The N terminus of Rep was found to specifically bind the acidic domain of ANP32B; through this interaction, Rep was also able to recruit other members of the TAF-I/Set complex, including the ANP32A protein and the histone chaperone TAF-I/Set. Further experiments revealed that silencing of ANP32A and ANP32B inhibited AAV replication, while overexpression of all of the components of the TAF-I/Set complex increased de novo AAV DNA synthesis in permissive cells. Besides being the first indication that the TAF-I/Set complex participates in wild-type AAV replication, these findings have important implications for the generation of recombinant AAV vectors since overexpression of the TAF-I/Set components was found to markedly increase viral vector production.
Collapse
Affiliation(s)
- Gianluca Pegoraro
- Molecular Medicine Laboratory, International Center for Genetic Engineering and Biotechnology, Triste, Italy
| | | | | | | |
Collapse
|
15
|
Costanzo RV, Vilá-Ortíz GJ, Perandones C, Carminatti H, Matilla A, Radrizzani M. Anp32e/Cpd1 regulates protein phosphatase 2A activity at synapses during synaptogenesis. Eur J Neurosci 2006; 23:309-24. [PMID: 16420440 DOI: 10.1111/j.1460-9568.2005.04555.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Anp32e/Cpd1, a member of the acidic nuclear phosphoprotein (Anp)32 family, is characterized by the presence of an amino terminal domain containing four leucine-rich repeats and a carboxyl-terminal low-compositional complexity acidic region. In previous studies performed to understand the biological role of Anp32e/Cpd1, we showed a predominant presence of Anp32e/Cpd1 in the nucleus. However, when Anp32e/Cpd1 is in the cytoplasm, it co-localizes spatially with protein phosphatase 2A (PP2A) near cell membranes, far from the synapses. In the present work, we show that Anp32e/Cpd1 is also present as a membrane-bound 74/76-kDa protein with a widespread distribution in the brain. We reveal that the expression, synthesis and half-life of this high-molecular-weight form of Anp32e/Cpd1 are spatially and temporally correlated with the cerebellar synaptogenesis period. We demonstrate that synaptic Anp32e/Cpd1 co-localizes, interacts and inhibits PP2A activity, and that phosphorylation of Anp32/Cpd1 is required for the Anp32e-PP2A interaction. Also, subcellular localization was shown with electronic microscopy. Finally, we examine Anp32e/Cpd1 and PP2A distribution in two ataxic mutant models, weaver and staggerer, and show that their co-localization in Purkinje cell dendrites depends on parallel fibre/Purkinje cell contacts. Based on these observations, we propose that Anp32e/Cpd1 mediates synaptogenesis process by modulating PP2A activity.
Collapse
Affiliation(s)
- Roxana V Costanzo
- Centro Nacional de Genética Médica, A.N.L.I.S, Programa Nacional de Genética Médica, Avenue, Las Heras 2670 (1425), Buenos Aires, Argentina
| | | | | | | | | | | |
Collapse
|
16
|
Fan Z, Zhang H, Zhang Q. Tumor suppressor pp32 represses cell growth through inhibition of transcription by blocking acetylation and phosphorylation of histone H3 and initiating its proapoptotic activity. Cell Death Differ 2005; 13:1485-94. [PMID: 16341127 DOI: 10.1038/sj.cdd.4401825] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
pp32 belongs to a family of leucine-rich acidic nuclear proteins, which play important roles in many cellular processes including regulation of chromatin remodeling, transcription, RNA transport, transformation and apoptosis. pp32 is described as a new tumor suppressor. It is unknown as to how pp32 works in tumor suppression. We found that overexpression of pp32 in human Jurkat T cells inhibits cell growth, and silenced pp32 promotes growth. We first showed that hyperacetylation and hyperphosphorylation of histone H3 are required for T-cell activation. Phosphorylation of histone H3 precedes acetylation during T-cell activation. pp32 specifically binds to histone H3 and blocks its acetylation and phosphorylation. pp32 directly initiates caspase activity and also promotes granzyme A-mediated caspase-independent cell death. Taken together, pp32 plays a repressive role by inhibiting transcription and triggering apoptosis.
Collapse
Affiliation(s)
- Z Fan
- National Laboratory of Biomacromolecules and Center for Infection and Immunity, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China.
| | | | | |
Collapse
|
17
|
Adegbola O, Pasternack GR. A pp32–retinoblastoma protein complex modulates androgen receptor-mediated transcription and associates with components of the splicing machinery. Biochem Biophys Res Commun 2005; 334:702-8. [PMID: 16009334 DOI: 10.1016/j.bbrc.2005.06.153] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2005] [Accepted: 06/26/2005] [Indexed: 11/28/2022]
Abstract
We have previously shown pp32 and the retinoblastoma protein interact. pp32 and the retinoblastoma protein are nuclear receptor transcriptional coregulators: the retinoblastoma protein is a coactivator for androgen receptor, the major regulator of prostate cancer growth, while pp32, which is highly expressed in prostate cancer, is a corepressor of the estrogen receptor. We now show pp32 increases androgen receptor-mediated transcription and the retinoblastoma protein modulates this activity. Using affinity purification and mass spectrometry, we identify members of the pp32-retinoblastoma protein complex as PSF and nonO/p54nrb, proteins implicated in coordinate regulation of nuclear receptor-mediated transcription and splicing. We show that the pp32-retinoblastoma protein complex is modulated during TPA-induced K562 differentiation. Present evidence suggests that nuclear receptors assemble multiprotein complexes to coordinately regulate transcription and mRNA processing. Our results suggest that pp32 and the retinoblastoma protein may be part of a multiprotein complex that coordinately regulates nuclear receptor-mediated transcription and mRNA processing.
Collapse
Affiliation(s)
- Onikepe Adegbola
- Division of Molecular Pathology, Department of Pathology, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | | |
Collapse
|
18
|
Tanimukai H, Grundke-Iqbal I, Iqbal K. Up-regulation of inhibitors of protein phosphatase-2A in Alzheimer's disease. THE AMERICAN JOURNAL OF PATHOLOGY 2005; 166:1761-71. [PMID: 15920161 PMCID: PMC1602412 DOI: 10.1016/s0002-9440(10)62486-8] [Citation(s) in RCA: 171] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 03/03/2005] [Indexed: 11/23/2022]
Abstract
The activity of protein phosphatase-2A (PP2A) is compromised and is believed to be a cause of the abnormal hyperphosphorylation of tau in Alzheimer's disease (AD) brain. We investigated in AD the role of the two known endogenous PP2A inhibitors, called I1(PP2A) and I2(PP2A), which regulate the intracellular activity of PP2A in mammalian tissues. We found a significant increase in the neocortical levels of I1(PP2A) and I2(PP2A) in AD as compared to control cases by in situ hybridization. The immunohistochemical studies revealed that I2(PP2A) was translocated from neuronal nuclei to cytoplasm in AD. The 39-kd full-length I2(PP2A) was selectively cleaved into an approximately 20-kd fragment in AD brain cytosol. Digestion of the recombinant human I2(PP2A) with AD brain extract showed an increase in the generation of the approximately 20 kd and other fragments of the inhibitor as compared to control brain extract. Double-immunohistochemical studies revealed co-localization of PP2A with PP2A inhibitors in neuronal cytoplasm and co-localization of the inhibitors with abnormally hyperphosphorylated tau. These studies suggest the possible involvement of I1(PP2A) and I2(PP2A) in the abnormal hyperphosphorylation of tau in AD.
Collapse
Affiliation(s)
- Hitoshi Tanimukai
- New York State Institute for Basic Research in Developmental Disabilities, Staten Island, New York 10314-6399, USA
| | | | | |
Collapse
|
19
|
Adegbola O, Pasternack GR. Phosphorylated retinoblastoma protein complexes with pp32 and inhibits pp32-mediated apoptosis. J Biol Chem 2005; 280:15497-502. [PMID: 15716273 DOI: 10.1074/jbc.m411382200] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The retinoblastoma gene product (Rb) is a tumor suppressor that affects apoptosis paradoxically. Most sporadic cancers inactivate Rb by preferentially targeting the pathway that regulates Rb phosphorylation, resulting in resistance to apoptosis; this contrasts with Rb inactivation by mutation, which is associated with high rates of apoptosis. How phosphorylated Rb protects cells from apoptosis is not well understood, but there is evidence that Rb may sequester a pro-apoptotic nuclear factor. pp32 (ANP32A) is a pro-apoptotic nuclear phosphoprotein, the expression of which is commonly increased in cancer. We report that hyperphosphorylated Rb interacts with pp32 but not with the closely related proteins pp32r1 and pp32r2. We further demonstrate that pp32-Rb interaction inhibits the apoptotic activity of pp32 and stimulates proliferation. These results suggest a mechanism whereby cancer cells gain both a proliferative and survival advantage when Rb is inactivated by hyperphosphorylation.
Collapse
Affiliation(s)
- Onikepe Adegbola
- Division of Molecular Pathology, Department of Pathology, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA
| | | |
Collapse
|
20
|
Tanimukai H, Grundke-Iqbal I, Iqbal K. Inhibitors of protein phosphatase-2A: topography and subcellular localization. ACTA ACUST UNITED AC 2004; 126:146-56. [PMID: 15249138 DOI: 10.1016/j.molbrainres.2004.04.003] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/15/2004] [Indexed: 11/27/2022]
Abstract
The mRNA and protein expressions of I1(PP2A) and I2(PP2A), the two inhibitors of protein phosphatase 2A (PP2A) were investigated in adult rat brain. The rat brain and human brain inhibitors showed similar molecular weights by Western blots. The cDNA probes for human brain I1(PP2A) and I2(PP2A) readily hybridized with the corresponding mRNAs of rat brain inhibitors in Northern blots. We detected 3.7 and 2.1 kb transcripts of I1(PP2A) and 2.9 and 2.0 kb transcripts of I2(PP2A) in rat brain. In situ hybridization revealed that the mRNAs of the two inhibitors were mainly localized in neurons. Strong expression of both I1(PP2A) and I2(PP2A) mRNAs were observed in the olfactory bulb, hippocampal pyramidal and dentate granule cell layers, and cerebellar Purkinje cell, granular and molecular layers. Moderate expression of I1(PP2A) and I2(PP2A) mRNAs were observed in the cerebral cortex, caudate putamen, thalamus, hypothalamus, amygdala and pontine nucleus. The expression of I1(PP2A) and I2(PP2A) and as well as of PP-2A was also investigated by immunohistochemistry using antibodies to each protein. The distribution patterns of the two inhibitor proteins were similar to those of their corresponding mRNAs and to the expression of PP-2A. While PP-2A was localized to neuronal perikarya, I1(PP2A) was observed both in the neuronal cytoplasm and the nucleus. I2(PP2A) had mainly nuclear localization but it could also be seen in the neuronal cytoplasm. All three proteins were also expressed in the neuropil. These studies suggest that PP-2A activity is probably regulated by I1(PP2A) and I2(PP2A) in the adult mammalian central nervous system, and that these inhibitors are conserved between rat and human brains.
Collapse
Affiliation(s)
- Hitoshi Tanimukai
- New York State Institute for Basic Research in Developmental Disabilities, 1050 Forest Hill Road, Staten Island, NY, 10314, USA
| | | | | |
Collapse
|
21
|
Opal P, Garcia JJ, McCall AE, Xu B, Weeber EJ, Sweatt JD, Orr HT, Zoghbi HY. Generation and characterization of LANP/pp32 null mice. Mol Cell Biol 2004; 24:3140-9. [PMID: 15060138 PMCID: PMC381670 DOI: 10.1128/mcb.24.8.3140-3149.2004] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The leucine-rich acidic nuclear protein (LANP) belongs to a family of evolutionarily conserved proteins that are characterized by an amino-terminal domain rich in leucine residues followed by a carboxy-terminal acidic tail. LANP has been implicated in the regulation of a variety of cellular processes including RNA transport, transcription, apoptosis, vesicular trafficking, and intracellular signaling. Abundantly expressed in the developing cerebellum, this protein has also been hypothesized to play a role in cerebellar morphogenesis. LANP has been implicated in disease biology as well, both as a mediator of toxicity in spinocerebellar ataxia type 1 and as a tumor suppressor in cancers of the breast and prostate. To better understand the function of this multifaceted protein, we have generated mice lacking LANP. Surprisingly, these mice are viable and fertile. In addition we could not discern any derangements in any of the major organ systems, including the nervous system, which we have studied in detail. Overall our results point to a functional redundancy of LANP's function, most likely provided by its closely related family members.
Collapse
Affiliation(s)
- Puneet Opal
- Department of Neurology, Baylor College of Medicine, Houston, Texas, USA.
| | | | | | | | | | | | | | | |
Collapse
|
22
|
Harada JN, Shevchenko A, Shevchenko A, Pallas DC, Berk AJ. Analysis of the adenovirus E1B-55K-anchored proteome reveals its link to ubiquitination machinery. J Virol 2002; 76:9194-206. [PMID: 12186903 PMCID: PMC136464 DOI: 10.1128/jvi.76.18.9194-9206.2002] [Citation(s) in RCA: 182] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2002] [Accepted: 06/12/2002] [Indexed: 12/26/2022] Open
Abstract
During the early phase of infection, the E1B-55K protein of adenovirus type 5 (Ad5) counters the E1A-induced stabilization of p53, whereas in the late phase, E1B-55K modulates the preferential nucleocytoplasmic transport and translation of the late viral mRNAs. The mechanism(s) by which E1B-55K performs these functions has not yet been clearly elucidated. In this study, we have taken a proteomics-based approach to identify and characterize novel E1B-55K-associated proteins. A multiprotein E1B-55K-containing complex was immunopurified from Ad5-infected HeLa cells and found to contain E4-orf6, as well as several cellular factors previously implicated in the ubiquitin-proteasome-mediated destruction of proteins, including Cullin-5, Rbx1/ROC1/Hrt1, and Elongins B and C. We further demonstrate that a complex containing these as well as other proteins is capable of directing the polyubiquitination of p53 in vitro. These ubiquitin ligase components were found in a high-molecular-mass complex of 800 to 900 kDa. We propose that these newly identified binding partners (Cullin-5, Elongins B and C, and Rbx1) complex with E1B-55K and E4-orf6 during Ad infection to form part of an E3 ubiquitin ligase that targets specific protein substrates for degradation. We further suggest that E1B-55K functions as the principal substrate recognition component of this SCF-type ubiquitin ligase, whereas E4-orf6 may serve to nucleate the assembly of the complex. Lastly, we describe the identification and characterization of two novel E1B-55K interacting factors, importin-alpha 1 and pp32, that may also participate in the functions previously ascribed to E1B-55K and E4-orf6.
Collapse
Affiliation(s)
- Josephine N Harada
- Molecular Biology Institute, University of California, Los Angeles, Los Angeles, California 90095-1570, USA
| | | | | | | | | |
Collapse
|
23
|
Seo SB, Macfarlan T, McNamara P, Hong R, Mukai Y, Heo S, Chakravarti D. Regulation of histone acetylation and transcription by nuclear protein pp32, a subunit of the INHAT complex. J Biol Chem 2002; 277:14005-10. [PMID: 11830591 DOI: 10.1074/jbc.m112455200] [Citation(s) in RCA: 112] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Histone acetylation by p300/CBP and PCAF coactivators is considered to be a key mechanism of chromatin modification and transcriptional regulation. A multiprotein cellular complex, INHAT (inhibitor of acetyltransferases), containing the Set/TAF-Ibeta oncoprotein and pp32 strongly inhibits the HAT activity of p300/CBP and PCAF by histone masking. Here we report that the INHAT complex and its subunits have overlapping but distinct HAT inhibitory and histone binding characteristics. We provide evidence suggesting that the histone binding and INHAT activity of pp32 can be regulated by its physical association with other INHAT subunits. In vivo colocalization and transfection studies show that pp32 INHAT domains are responsible for histone binding, HAT inhibitory activity, and repression of transcription. We propose that INHAT and its subunits may function by modulating histone acetyltransferases through a histone-masking mechanism and may play important regulatory roles in the establishment and maintenance of the newly proposed "histone code" of chromatin.
Collapse
Affiliation(s)
- Sang-beom Seo
- Department of Pharmacology, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104, USA
| | | | | | | | | | | | | |
Collapse
|
24
|
Oda M, Sun W, Hattori N, Tanaka S, Shiota K. PAL31 expression in rat trophoblast giant cells. Biochem Biophys Res Commun 2001; 287:721-6. [PMID: 11563855 DOI: 10.1006/bbrc.2001.5646] [Citation(s) in RCA: 6] [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
PAL31 is a proliferation-related acidic nuclear protein that belongs to the leucine-rich protein family and is expressed cell-cycle-dependently. Trophoblasts differentiate into the trophoblast giant cells (TGCs) through the unusual type of cell cycle, namely endoreduplication. In the present study, we investigated the spatiotemporal pattern of PAL31 expression in rat placenta and Rcho-1 cell line. The PAL31 mRNA concentration varied in different areas of the placenta, and was barely detectable in the TGC layer. In Rcho-1 cells, although the level of PAL31 mRNA decreased dramatically during differentiation, PAL31 was detected even after differentiation. The site of intranuclear localization of PAL31 mostly overlapped with that of PCNA in the undifferentiated Rcho-1 cells, while they were not overlapped in differentiated cells. Thus, the subcellular localization of PAL31 in Rcho-1 cells significantly changed, and loss of cell cycle dependency after differentiation was noted. PAL31 is suggested to play a role in the endoreduplication distinct from the usual DNA duplication.
Collapse
Affiliation(s)
- M Oda
- Laboratory of Cellular Biochemistry, Animal Resource Sciences/Veterinary Medical Sciences, University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, 113-8657, Japan
| | | | | | | | | |
Collapse
|
25
|
van Leenders GJ, Schalken JA. Stem cell differentiation within the human prostate epithelium: implications for prostate carcinogenesis. BJU Int 2001; 88 Suppl 2:35-42; discussion 49-50. [PMID: 11589668 DOI: 10.1046/j.1464-410x.2001.00117.x] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Affiliation(s)
- G J van Leenders
- Department of Pathology, University Medical Centre St. Radboud, Nijmegen, The Netherlands.
| | | |
Collapse
|
26
|
Sun W, Hattori N, Mutai H, Toyoshima Y, Kimura H, Tanaka S, Shiota K. PAL31, a nuclear protein required for progression to the S phase. Biochem Biophys Res Commun 2001; 280:1048-54. [PMID: 11162633 DOI: 10.1006/bbrc.2000.4244] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
PAL31 is a nuclear protein expressed by various cell types. In the present study, the expression and function of PAL31 were examined in the cytokine-regulated growth of T and B cell lines. Treatment of the cells with mitogens [ovine PRL, recombinant rat placental lactogen-I (PL-I) and human IL-3] caused a dose-dependent increase in the expression of PAL31 mRNA in the PRL-dependent cell line Nb2, and IL-3 dependent cell line BaF3. A time-course study on synchronized Nb2 cells revealed that the expression of PAL31 is specific to the late G1 and S phases. Immunocytological studies revealed that PAL31 accumulates in the nuclei at the S phase. Furthermore, the antisense oligonucleotide for PAL31 severely inhibited the proliferation of Nb2 cells by inhibiting cells progressing to the S phase. Thus, PAL31 is a nuclear protein associated with cell cycle progression.
Collapse
Affiliation(s)
- W Sun
- Laboratory of Cellular Biochemistry, Animal Resource Sciences/Veterinary Medical Sciences, University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, 113-8657, Japan
| | | | | | | | | | | | | |
Collapse
|
27
|
Brennan CM, Gallouzi IE, Steitz JA. Protein ligands to HuR modulate its interaction with target mRNAs in vivo. J Cell Biol 2000; 151:1-14. [PMID: 11018049 PMCID: PMC2189805 DOI: 10.1083/jcb.151.1.1] [Citation(s) in RCA: 301] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2000] [Accepted: 08/15/2000] [Indexed: 02/08/2023] Open
Abstract
AU-rich elements (AREs) present in the 3' untranslated regions of many protooncogene, cytokine, and lymphokine messages target them for rapid degradation. HuR, a ubiquitously expressed member of the ELAV (embryonic lethal abnormal vision) family of RNA binding proteins, selectively binds AREs and stabilizes ARE-containing mRNAs in transiently transfected cells. Here, we identify four mammalian proteins that bind regions of HuR known to be essential for its ability to shuttle between the nucleus and the cytoplasm and to stabilize mRNA: SETalpha, SETbeta, pp32, and acidic protein rich in leucine (APRIL). Three have been reported to be protein phosphatase 2A inhibitors. All four ligands contain long, acidic COOH-terminal tails, while pp32 and APRIL share a second motif: rev-like leucine-rich repeats in their NH(2)-terminal regions. We show that pp32 and APRIL are nucleocytoplasmic shuttling proteins that interact with the nuclear export factor CRM1 (chromosomal region maintenance protein 1). The inhibition of CRM1 by leptomycin B leads to the nuclear retention of pp32 and APRIL, their increased association with HuR, and an increase in HuR's association with nuclear poly(A)+ RNA. Furthermore, transcripts from the ARE-containing c-fos gene are selectively retained in the nucleus, while the cytoplasmic distribution of total poly(A)+ RNA is not altered. These data provide evidence that interaction of its ligands with HuR modulate HuR's ability to bind its target mRNAs in vivo and suggest that CRM1 is instrumental in the export of at least some cellular mRNAs under certain conditions. We discuss the possible role of these ligands upstream of HuR in pathways that govern the stability of ARE-containing mRNAs.
Collapse
Affiliation(s)
- C M Brennan
- Department of Molecular Biophysics and Biochemistry, Howard Hughes Medical Institute, Yale University School of Medicine, New Haven, Connecticut 06536, USA
| | | | | |
Collapse
|
28
|
Mutai H, Toyoshima Y, Sun W, Hattori N, Tanaka S, Shiota K. PAL31, a novel nuclear protein, expressed in the developing brain. Biochem Biophys Res Commun 2000; 274:427-33. [PMID: 10913355 DOI: 10.1006/bbrc.2000.3133] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We cloned a cDNA encoding a novel protein (PAL31) predominantly expressed in the fetal rat brain by differential display. PAL31 contains leucine-rich repeat domains, a highly acidic region and a putative nuclear localization signal. PAL31 has 50-70% similarity to SSP29, APRIL, LANP, PHAP I, and PP32. Expression of PAL31 mRNA in the brain was high during the fetal period and decreased after birth. Immunohistochemical studies showed that PAL31 is expressed in the entire embryonic brain, whereas in the adult brain its expression is restricted to the subventricular zone where there are neural progenitor cells. It was also revealed that PAL31 is colocalized with PCNA in the nucleus, indicating that the PAL31 expression is developmentally regulated. Considering the primary structure of PAL31 and its spatiotemporal expression pattern, PAL31 is a novel nuclear protein related to the development of the brain through the proliferation of neuronal cells.
Collapse
Affiliation(s)
- H Mutai
- Laboratory of Cellular Biochemistry, University of Tokyo, Tokyo, 113-8657, Japan
| | | | | | | | | | | |
Collapse
|
29
|
Brody JR, Kadkol SS, Mahmoud MA, Rebel JM, Pasternack GR. Identification of sequences required for inhibition of oncogene-mediated transformation by pp32. J Biol Chem 1999; 274:20053-5. [PMID: 10400610 DOI: 10.1074/jbc.274.29.20053] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Oncogenic potential in prostate cancer is modulated in part by alternative use of genes of the pp32 family. This family includes the tumor suppressor pp32, expressed in normal tissue, and the pro-oncogenic genes pp32r1 and pp32r2 that are found principally in neoplastic cells. At the protein level, pp32, pp32r1, and pp32r2 are approximately 90% identical, yet they subsume opposite functions. In this study, we identify the region of pp32 associated with the ability to inhibit oncogene-mediated transformation in a rat embryo fibroblast system, an in vitro correlate of tumor-suppressive activity. Deletion and truncation analysis define a region spanning pp32 amino acids 150-174 as absolutely required for inhibition of transformed foci elicited by RAS and MYC. Comparison of pp32 with the pp32r1 sequence by moving averages of sequence identity reveals divergence over this region; pp32r2 also differs in this region through truncation after pp32 amino acid 131. The deletion experiments and the experiments of nature therefore converge to demonstrate that tumor-suppressive functions of pp32 reside in amino acids 150-174. Identification of this minimal tumor-suppressive region should help elaborate the pathways and mechanisms through which pp32 family members exert their functions.
Collapse
Affiliation(s)
- J R Brody
- Division of Molecular Pathology, Department of Pathology, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA
| | | | | | | | | |
Collapse
|
30
|
|
31
|
Kadkol SS, Brody JR, Pevsner J, Bai J, Pasternack GR. Modulation of oncogenic potential by alternative gene use in human prostate cancer. Nat Med 1999; 5:275-9. [PMID: 10086381 DOI: 10.1038/6488] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Only a small percentage of primary prostate cancers have genetic changes. In contrast, nearly 90% of clinically significant human prostate cancers seems to express high levels of the nuclear phosphoprotein pp32 by in situ hybridization. Because pp32 inhibits oncogene-mediated transformation, we investigated its paradoxical expression in cancer by comparing the sequence and function of pp32 species from paired benign prostate tissue and adjacent prostatic carcinoma from three patients. Here we demonstrate that pp32 is expressed in benign prostatic tissue, but pp32r1 and pp32r2, closely-related genes located on different chromosomes, are expressed in prostate cancer. Although pp32 is a tumor suppressor, pp32r1 and pp32r2 are tumorigenic. Alternative use of the pp32, pp32r1 and pp32r2 genes may modulate the oncogenic potential of human prostate cancer.
Collapse
Affiliation(s)
- S S Kadkol
- Department of Pathology, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA
| | | | | | | | | |
Collapse
|
32
|
De Marzo AM, Nelson WG, Meeker AK, Coffey DS. Stem cell features of benign and malignant prostate epithelial cells. J Urol 1998; 160:2381-92. [PMID: 9817389 DOI: 10.1097/00005392-199812020-00004] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
PURPOSE We present a new hypothesis suggesting that the different malignant potential of benign prostatic hyperplasia (BPH) and high grade prostatic intraepithelial neoplasia may be explained by distinct alterations in stem cell-like properties. MATERIALS AND METHODS We used our results and the recent literature to develop this hypothesis in the context of an updated prostate stem cell model. RESULTS While high grade prostatic intraepithelial neoplasia is a likely precursor lesion to many prostatic adenocarcinomas, BPH rarely if ever progresses directly to carcinoma. Prostate epithelium contains basal and secretory compartments. Secretory cells appear to differentiate from basal cells. Thus, prostatic stem cells most likely reside in the basal compartment. In BPH there is a slight increase in epithelial proliferation, yet most replicating epithelial cells within BPH maintain their normal restriction to the basal compartment. In high grade prostatic intraepithelial neoplasia there is a marked increase in cell proliferation. In contrast to BPH, the majority of proliferating cells in high grade prostatic intraepithelial neoplasia reside in the secretory compartment. The biological significance of this topographic infidelity of proliferation in high grade prostatic intraepithelial neoplasia remains unclear but may relate mechanistically to down regulation of the cyclin dependent kinase inhibitor, p27kip1. Normal basal cells express GSTP1, an enzyme that inactivates reactive electrophiles and organic hydroperoxides, and that may protect cells from deoxyribonucleic acid damaging agents. In contrast, normal secretory cells and high grade prostatic intraepithelial neoplasia cells do not express this enzyme. CONCLUSIONS We propose that topographic infidelity of proliferation produces a population of secretory cells replicating in the absence of key genome protective mechanisms, thus setting the stage for an accumulation of genomic alterations and instability in high grade prostatic intraepithelial neoplasia. This action occurs along with activation of telomerase, resulting in an immortal clone capable of developing into invasive carcinoma. The model predicts that genome protection remains intact in BPH, minimizing its malignant potential.
Collapse
Affiliation(s)
- A M De Marzo
- Department of Pathology, James Buchanan Brady Urological Institute, The Johns Hopkins University Medical Institutions, Baltimore, Maryland, USA
| | | | | | | |
Collapse
|
33
|
DE MARZO ANGELOM, NELSON WILLIAMG, MEEKER ALANK, COFFEY DONALDS. STEM CELL FEATURES OF BENIGN AND MALIGNANT PROSTATE EPITHELIAL CELLS. J Urol 1998. [DOI: 10.1016/s0022-5347(01)62196-7] [Citation(s) in RCA: 73] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
|
34
|
Wirth PJ, Luo LD, Hoang T, Benjamin T. Two-dimensional polyacrylamide gel electrophoresis of cancer-associated proteins. Recent Results Cancer Res 1997; 143:145-60. [PMID: 8912417 DOI: 10.1007/978-3-642-60393-8_10] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Affiliation(s)
- P J Wirth
- Biopolymer Chemistry Section, National Cancer Institute, Bethesda, MD 20893, USA
| | | | | | | |
Collapse
|
35
|
Gusev Y, Romantsev FE, Chen TT, Kayler AE, Kuhajda FP, Dooley WC, Pasternack GR. pp32 overexpression induces nuclear pleomorphism in rat prostatic carcinoma cells. Cell Prolif 1996; 29:643-53. [PMID: 9146727 DOI: 10.1111/j.1365-2184.1996.tb00978.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Nuclear pleomorphism is an important diagnostic factor in tumour pathology. Traditionally, nuclear pleomorphism is evaluated qualitatively or semiquantitatively, often as a component of tumour grade; the molecular basis of nuclear pleomorphism, however, remains unclear. In this study, we investigated the quantitative effects on nuclear morphology of overexpressing pp32, a recently described nuclear phosphoprotein highly expressed in self-renewing and neoplastic cell populations. Assessment of Feulgen-stained transfected and control lines of AT3.1, a rat prostatic carcinoma cell line, using a computerized Cellular Image Analysis System (BD CAS-200) showed that stable overexpression of human pp32 in AT3.1 cells is accompanied by marked increases in the coefficient of variation of nuclear shape, nuclear size and chromatin textures but not in DNA content. In contrast, stable transfection with control vector, with ras, or with bcl-2 failed to affect nuclear morphology. Cell cycle analysis further showed that pp32-related increases in variation of nuclear structure manifested principally in G1. These studies suggest that pp32 plays a role either directly or indirectly in the control of nuclear shape of G1 cells.
Collapse
Affiliation(s)
- Y Gusev
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA
| | | | | | | | | | | | | |
Collapse
|
36
|
Wirth PJ. Two-dimensional polyacrylamide gel electrophoresis in experimental hepatocarcinogenesis studies. Electrophoresis 1994; 15:358-71. [PMID: 8055866 DOI: 10.1002/elps.1150150155] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
High resolution two-dimensional polyacrylamide gel electrophoresis (2-D PAGE) in combination with computer-assisted densitometry was used to analyze sequential changes in polypeptide expression during chemically (aflatoxin Bl; AFB), spontaneously, and oncogene (v-Ha-ras, v-raf, and v-raflv-myc)-induced experimental rat hepatocarcinogenesis. Two-dimensional mapping of [35S]methionine and [32P]orthophosphate-labeled whole cell lysate and nuclear polypeptides revealed subsets of polypeptides specific for each transformation modality in the in vitro rat liver epithelial (RLE) transformation model. Many of the observed changes in whole cell lysate preparations were localized to specific subcellular organelles. Significant alterations in the expression of the extracellular matrix protein, fibronectin, as well as tropomyosin- and intermediate filament-related polypeptides (vimentin, beta-tubulin, cytokeratins 8, 14, and 18, and actin) were observed among the various transformant cell lines. Whereas alterations in the tropomyosin isoforms appeared to be transformation specific, concomitant modulation of intermediate filament expression was related more to the differentiation state of the individual cell lines than to the transformed phenotype. To integrate protein and DNA information of polypeptides believed to be critically involved during cellular transformation, N-terminal amino acid microsequencing of selected nuclear polypeptides was performed. Preliminary results suggest that N-terminal blockage of rat liver epithelial nuclear proteins to be minor (approximately 20%) with sequencing sensitivity of one pmol. These studies extend our on-going efforts toward the establishment of computerized database of rat liver epithelial cellular proteins (Wirth et al., Electrophoresis, 1991, 12, 931-954) to aid in the delineation of polypeptides critically involved in cellular growth and differentiation as well as transformation.
Collapse
Affiliation(s)
- P J Wirth
- Biopolymer Chemistry Section, National Cancer Institute, Bethesda, MD 20892
| |
Collapse
|
37
|
Wirth PJ, Luo LD, Benjamin T, Hoang TN, Olson AD, Parmelee DC. The rat liver epithelial (RLE) cell nuclear protein database. Electrophoresis 1993; 14:1199-215. [PMID: 7508859 DOI: 10.1002/elps.11501401180] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The master two-dimensional computer database of rat liver epithelial (RLE) cellular proteins (Wirth et al., Electrophoresis 1991, 12, 931-954) has been expanded to include detailed information concerning 1100 nucleoplasmic (cytosolic) and 850 particulate associated [35S]methionine labeled as well as 215 nucleoplasmic and 269 particulate associated [32P]orthophosphate labeled RLE nuclear polypeptides, respectively. The RLE nuclear protein database developed using the Elsie 5 gel analysis system contains both qualitative and quantitative annotations including polypeptide identification number, protein name (if known), molecular weight and pI information, quantitation and polypeptide spot shape, subcellular location, as well as specific information regarding transformation (chemical and spontaneous) and growth-related characteristics. Microsequencing of polypeptides directly from two-dimensional (2-D) blotted membranes has recently been established in our laboratory and provides a highly efficient and rapid means of polypeptide identification in the absence of specific antibodies. At present the RLE protein database is still in the developmental stage and is continually being updated as additional information is obtained. Nonetheless, it is anticipated that knowledge obtained concerning the identification and characterization of specific transformation and/or growth regulatory proteins in the RLE in vitro cell system will not only have direct application to other rodent and human 2-D protein databases currently under development but will also complement them.
Collapse
Affiliation(s)
- P J Wirth
- Biopolymer Chemistry Section, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892
| | | | | | | | | | | |
Collapse
|
38
|
Abstract
The present review on casein kinases focuses mainly on the possible metabolic role of CK-2, with special emphasis on its behavior in pathological tissues. From these data at least three ways to regulate CK-2 activity emerge: (i) CK-2 activity changes during embryogenesis, being high at certain stages of development and showing basal activity values at others; (ii) CK-2 activity can be enhanced in vitro by treatment of tissue culture cells with various growth factors and serum and (iii) CK-2 activity is constitutively enhanced in rapidly proliferating cells. The regulated CK-2 activity changes during embryogenesis cannot be explained as yet. In the case of the constitutive high expression of CK-2 in tumors, genetic changes may be responsible, e.g. through alterations of the regulatory genetic elements and/or regulation by specific transcription factors. In the case of serum induction, no genetic changes are necessarily involved; the observed changes may be entirely due to a signal transduction pathway where CK-2 could be phosphorylated by another kinase(s). CK-2 cDNAs from various organisms have been isolated and characterized. From the deduced amino acid sequence it turns out that CK-2 subunits are highly conserved during evolution. The relationship between CK-2 alpha from humans and plants is still 73%. Similar relationships are reported for the beta-subunit. Chromosomal assignment of CK-2 alpha shows two gene loci, one of which is a pseudogene. They are located on different chromosomes. Expression of the CK-2 subunits in Escherichia coli and the Baculo expression system is shown. The recombinant subunits can self-assemble to a functional holoenzyme in vitro. Biochemical and biophysical analysis of the recombinant beta-subunit suggests it to be trifunctional in association with the alpha-subunit affecting: (i) stability, (ii) enzyme specificity and (iii) enzyme activity. The question where CK-2 and its subunits are located throughout the cell cycle has also been addressed, mainly because of the large discrepancies that still exist between results obtained by different investigators. Tissue-specific expression of CK-2 at the mRNA and at the protein level has also been given attention. The fact that the enzyme activity is surprisingly high in brain and low in heart and lung may be indicative of involvement of CK-2 in processes other than proliferation.(ABSTRACT TRUNCATED AT 400 WORDS)
Collapse
Affiliation(s)
- O G Issinger
- Medizinische Fakultät, Universität des Saarlandes, Homburg (Saar), Germany
| |
Collapse
|
39
|
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.
Collapse
Affiliation(s)
- M G Barcia
- Departamento de Bioquímica e Bioloxía Molecular, Facultade de Bioloxía, Universidade de Santiago, Galicia, Spain
| | | | | | | | | |
Collapse
|