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Wang Y, Zhang S, Sun Q, Yuan F, Zhao L, Ye Z, Li Y, Wang R, Jiang H, Hu P, Tian D, Liu B. WAC, a novel GBM tumor suppressor, induces GBM cell apoptosis and promotes autophagy. Med Oncol 2021; 38:132. [PMID: 34581882 DOI: 10.1007/s12032-021-01580-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2021] [Accepted: 09/12/2021] [Indexed: 10/20/2022]
Abstract
WAC is closely related to the occurrence and development of tumors. However, its role in human glioblastoma (GBM) and its potential regulatory mechanisms have not been investigated. This study demonstrated that WAC is downregulated in GBM, and its low expression predicts a poor prognosis. We investigated the effect of WAC on the proliferation of glioma cells through a CCK-8 assay, EdU incorporation, and cell formation. The effects of WAC on apoptosis and autophagy in glioma were determined by flow cytometry, TUNEL detection, immunofluorescence, q-PCR, WB, and scanning electron microscopy. We found that overexpression of WAC inhibited the proliferation of glioma cells, promoted apoptosis, and induced autophagy. Therefore, WAC is likely to play a role as a new regulatory molecule in glioma.
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Affiliation(s)
- Yixuan Wang
- Department of Neurosurgery, Renmin Hospital of Wuhan University, 238 Jiefang Street, Wuhan, 430060, Hubei, China.,Central Laboratory, Renmin Hospital of Wuhan University, Wuhan, 430060, Hubei, China
| | - Si Zhang
- Department of Neurosurgery, Renmin Hospital of Wuhan University, 238 Jiefang Street, Wuhan, 430060, Hubei, China.,Central Laboratory, Renmin Hospital of Wuhan University, Wuhan, 430060, Hubei, China
| | - Qian Sun
- Department of Neurosurgery, Renmin Hospital of Wuhan University, 238 Jiefang Street, Wuhan, 430060, Hubei, China.,Central Laboratory, Renmin Hospital of Wuhan University, Wuhan, 430060, Hubei, China
| | - Fan'en Yuan
- Department of Neurosurgery, Renmin Hospital of Wuhan University, 238 Jiefang Street, Wuhan, 430060, Hubei, China.,Central Laboratory, Renmin Hospital of Wuhan University, Wuhan, 430060, Hubei, China
| | - Linyao Zhao
- Department of Neurosurgery, Renmin Hospital of Wuhan University, 238 Jiefang Street, Wuhan, 430060, Hubei, China.,Central Laboratory, Renmin Hospital of Wuhan University, Wuhan, 430060, Hubei, China
| | - Zhang Ye
- Department of Neurosurgery, Renmin Hospital of Wuhan University, 238 Jiefang Street, Wuhan, 430060, Hubei, China.,Central Laboratory, Renmin Hospital of Wuhan University, Wuhan, 430060, Hubei, China
| | - Yong Li
- Department of Neurosurgery, Renmin Hospital of Wuhan University, 238 Jiefang Street, Wuhan, 430060, Hubei, China.,Central Laboratory, Renmin Hospital of Wuhan University, Wuhan, 430060, Hubei, China
| | - Ronggui Wang
- Department of Neurosurgery, Renmin Hospital of Wuhan University, 238 Jiefang Street, Wuhan, 430060, Hubei, China.,Central Laboratory, Renmin Hospital of Wuhan University, Wuhan, 430060, Hubei, China
| | - Hongxiang Jiang
- Department of Neurosurgery, Renmin Hospital of Wuhan University, 238 Jiefang Street, Wuhan, 430060, Hubei, China.,Central Laboratory, Renmin Hospital of Wuhan University, Wuhan, 430060, Hubei, China
| | - Ping Hu
- Department of Neurosurgery, Renmin Hospital of Wuhan University, 238 Jiefang Street, Wuhan, 430060, Hubei, China.,Central Laboratory, Renmin Hospital of Wuhan University, Wuhan, 430060, Hubei, China
| | - Daofeng Tian
- Department of Neurosurgery, Renmin Hospital of Wuhan University, 238 Jiefang Street, Wuhan, 430060, Hubei, China. .,Central Laboratory, Renmin Hospital of Wuhan University, Wuhan, 430060, Hubei, China.
| | - Baohui Liu
- Department of Neurosurgery, Renmin Hospital of Wuhan University, 238 Jiefang Street, Wuhan, 430060, Hubei, China. .,Central Laboratory, Renmin Hospital of Wuhan University, Wuhan, 430060, Hubei, China.
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2
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Zannini A, Rustighi A, Campaner E, Del Sal G. Oncogenic Hijacking of the PIN1 Signaling Network. Front Oncol 2019; 9:94. [PMID: 30873382 PMCID: PMC6401644 DOI: 10.3389/fonc.2019.00094] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2018] [Accepted: 02/01/2019] [Indexed: 12/18/2022] Open
Abstract
Cellular choices are determined by developmental and environmental stimuli through integrated signal transduction pathways. These critically depend on attainment of proper activation levels that in turn rely on post-translational modifications (PTMs) of single pathway members. Among these PTMs, post-phosphorylation prolyl-isomerization mediated by PIN1 represents a unique mechanism of spatial, temporal and quantitative control of signal transduction. Indeed PIN1 was shown to be crucial for determining activation levels of several pathways and biological outcomes downstream to a plethora of stimuli. Of note, studies performed in different model organisms and humans have shown that hormonal, nutrient, and oncogenic stimuli simultaneously affect both PIN1 activity and the pathways that depend on PIN1-mediated prolyl-isomerization, suggesting the existence of evolutionarily conserved molecular circuitries centered on this isomerase. This review focuses on molecular mechanisms and cellular processes like proliferation, metabolism, and stem cell fate, that are regulated by PIN1 in physiological conditions, discussing how these are subverted in and hijacked by cancer cells. Current status and open questions regarding the use of PIN1 as biomarker and target for cancer therapy as well as clinical development of PIN1 inhibitors are also addressed.
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Affiliation(s)
- Alessandro Zannini
- National Laboratory CIB, Trieste, Italy.,Department of Life Sciences, University of Trieste, Trieste, Italy
| | - Alessandra Rustighi
- National Laboratory CIB, Trieste, Italy.,Department of Life Sciences, University of Trieste, Trieste, Italy
| | | | - Giannino Del Sal
- National Laboratory CIB, Trieste, Italy.,Department of Life Sciences, University of Trieste, Trieste, Italy.,IFOM - Istituto FIRC Oncologia Molecolare, Milan, Italy
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3
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Kang SW, Lee E, Cho E, Seo JH, Ko HW, Kim EY. Drosophila peptidyl-prolyl isomerase Pin1 modulates circadian rhythms via regulating levels of PERIOD. Biochem Biophys Res Commun 2015; 463:235-40. [PMID: 25998391 DOI: 10.1016/j.bbrc.2015.05.033] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2015] [Accepted: 05/10/2015] [Indexed: 12/13/2022]
Abstract
In animal circadian clock machinery, the phosphorylation program of PERIOD (PER) leads to the spatio-temporal regulation of diverse PER functions, which are crucial for the maintenance of ~24-hr circadian rhythmicity. The peptidyl-prolyl isomerase PIN1 modulates the diverse functions of its substrates by inducing conformational changes upon recognizing specific phosphorylated residues. Here, we show that overexpression of Drosophila pin1, dodo (dod), lengthens the locomotor behavioral period. Using Drosophila S2 cells, we demonstrate that Dod associates preferentially with phosphorylated species of PER, which delays the phosphorylation-dependent degradation of PER. Consistent with this, PER protein levels are higher in flies overexpressing dod. Taken together, we suggest that Dod plays a role in the maintenance of circadian period by regulating PER metabolism.
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Affiliation(s)
- So Who Kang
- Neuroscience Graduate Program, Department of Biomedical Sciences, Ajou University School of Medicine, 164 Worldcup-ro, Yeongtong-gu, Suwon, Kyunggi-do, 443-380, Republic of Korea; Department of Brain Science, Ajou University School of Medicine, 164 Worldcup-ro, Yeongtong-gu, Suwon, Kyunggi-do, 443-380, Republic of Korea
| | - Euna Lee
- Neuroscience Graduate Program, Department of Biomedical Sciences, Ajou University School of Medicine, 164 Worldcup-ro, Yeongtong-gu, Suwon, Kyunggi-do, 443-380, Republic of Korea; Department of Brain Science, Ajou University School of Medicine, 164 Worldcup-ro, Yeongtong-gu, Suwon, Kyunggi-do, 443-380, Republic of Korea
| | - Eunjoo Cho
- Department of Brain Science, Ajou University School of Medicine, 164 Worldcup-ro, Yeongtong-gu, Suwon, Kyunggi-do, 443-380, Republic of Korea; Chronic Inflammatory Disease Research Center, Ajou University School of Medicine, 164 Worldcup-ro, Yeongtong-gu, Suwon, Kyunggi-do, 443-380, Republic of Korea
| | - Ji Hye Seo
- Department of Brain Science, Ajou University School of Medicine, 164 Worldcup-ro, Yeongtong-gu, Suwon, Kyunggi-do, 443-380, Republic of Korea
| | - Hyuk Wan Ko
- College of Pharmacy, Dongguk University, 32 Donggukro, Ilsandonggu, Goyangsi, Gyeonggido, 410-820, Republic of Korea
| | - Eun Young Kim
- Neuroscience Graduate Program, Department of Biomedical Sciences, Ajou University School of Medicine, 164 Worldcup-ro, Yeongtong-gu, Suwon, Kyunggi-do, 443-380, Republic of Korea; Department of Brain Science, Ajou University School of Medicine, 164 Worldcup-ro, Yeongtong-gu, Suwon, Kyunggi-do, 443-380, Republic of Korea; Chronic Inflammatory Disease Research Center, Ajou University School of Medicine, 164 Worldcup-ro, Yeongtong-gu, Suwon, Kyunggi-do, 443-380, Republic of Korea.
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4
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Kianianmomeni A, Ong CS, Rätsch G, Hallmann A. Genome-wide analysis of alternative splicing in Volvox carteri. BMC Genomics 2014; 15:1117. [PMID: 25516378 PMCID: PMC4378016 DOI: 10.1186/1471-2164-15-1117] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2014] [Accepted: 12/11/2014] [Indexed: 11/15/2022] Open
Abstract
Background Alternative splicing is an essential mechanism for increasing transcriptome and proteome diversity in eukaryotes. Particularly in multicellular eukaryotes, this mechanism is involved in the regulation of developmental and physiological processes like growth, differentiation and signal transduction. Results Here we report the genome-wide analysis of alternative splicing in the multicellular green alga Volvox carteri. The bioinformatic analysis of 132,038 expressed sequence tags (ESTs) identified 580 alternative splicing events in a total of 426 genes. The predominant type of alternative splicing in Volvox is intron retention (46.5%) followed by alternative 5′ (17.9%) and 3′ (21.9%) splice sites and exon skipping (9.5%). Our analysis shows that in Volvox at least ~2.9% of the intron-containing genes are subject to alternative splicing. Considering the total number of sequenced ESTs, the Volvox genome seems to provide more favorable conditions (e.g., regarding length and GC content of introns) for the occurrence of alternative splicing than the genome of its close unicellular relative Chlamydomonas. Moreover, many randomly chosen alternatively spliced genes of Volvox do not show alternative splicing in Chlamydomonas. Since the Volvox genome contains about the same number of protein-coding genes as the Chlamydomonas genome (~14,500 protein-coding genes), we assumed that alternative splicing may play a key role in generation of genomic diversity, which is required to evolve from a simple one-cell ancestor to a multicellular organism with differentiated cell types (Mol Biol Evol 31:1402-1413, 2014). To confirm the alternative splicing events identified by bioinformatic analysis, several genes with different types of alternatively splicing have been selected followed by experimental verification of the predicted splice variants by RT-PCR. Conclusions The results show that our approach for prediction of alternative splicing events in Volvox was accurate and reliable. Moreover, quantitative real-time RT-PCR appears to be useful in Volvox for analyses of relationships between the appearance of specific alternative splicing variants and different kinds of physiological, metabolic and developmental processes as well as responses to environmental changes. Electronic supplementary material The online version of this article (doi:10.1186/1471-2164-15-1117) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Arash Kianianmomeni
- Department of Cellular and Developmental Biology of Plants, University of Bielefeld, Universitätsstr, 25, D-33615 Bielefeld, Germany.
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5
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Sami F, Smet-Nocca C, Khan M, Landrieu I, Lippens G, Brautigan DL. Molecular basis for an ancient partnership between prolyl isomerase Pin1 and phosphatase inhibitor-2. Biochemistry 2011; 50:6567-78. [PMID: 21714498 DOI: 10.1021/bi200553e] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Pin1 is a prolyl isomerase that recognizes phosphorylated Ser/Thr-Pro sites, and phosphatase inhibitor-2 (I-2) is phosphorylated during mitosis at a PSpTP site that is expected to be a Pin1 substrate. However, we previously discovered I-2, but not phospho-I-2, bound to Pin1 as an allosteric modifier of Pin1 substrate specificity [Li, M., et al. (2008) Biochemistry 47, 292]. Here, we use binding assays and NMR spectroscopy to map the interactions on Pin1 and I-2 to elucidate the organization of this complex. Despite having sequences that are ∼50% identical, human, Xenopus, and Drosophila I-2 proteins all exhibited identical, saturable binding to GST-Pin1 with K(0.5) values of 0.3 μM. The (1)H-(15)N heteronuclear single-quantum coherence spectra for both the WW domain and isomerase domain of Pin1 showed distinctive shifts upon addition of I-2. Conversely, as shown by NMR spectroscopy, specific regions of I-2 were affected by addition of Pin1. A single-residue I68A substitution in I-2 weakened binding to Pin1 by half and essentially eliminated binding to the isolated WW domain. On the other hand, truncation of I-2 to residue 152 had a minimal effect on binding to the WW domain but eliminated binding to the isomerase domain. Size exclusion chromatography revealed that wild-type I-2 and Pin1 formed a large (>300 kDa) complex and I-2(I68A) formed a complex of half the size that we propose are a heterotetramer and a heterodimer, respectively. Pin1 and I-2 are conserved among eukaryotes from yeast to humans, and we propose they make up an ancient partnership that provides a means for regulating Pin1 specificity and function.
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Affiliation(s)
- Furqan Sami
- Center for Cell Signaling and Department of Microbiology, University of Virginia School of Medicine, Box 800577-MSB7225, Charlottesville, Virginia 22908, United States
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6
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Pemberton TJ, Kay JE. Identification and comparative analysis of the peptidyl-prolyl cis/trans isomerase repertoires of H. sapiens, D. melanogaster, C. elegans, S. cerevisiae and Sz. pombe. Comp Funct Genomics 2010; 6:277-300. [PMID: 18629211 PMCID: PMC2447506 DOI: 10.1002/cfg.482] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2005] [Revised: 05/01/2005] [Accepted: 05/26/2005] [Indexed: 11/11/2022] Open
Abstract
The peptidyl-prolyl cis/trans isomerase (PPIase) class of proteins comprises three
member families that are found throughout nature and are present in all the major
compartments of the cell. Their numbers appear to be linked to the number of genes in
their respective genomes, although we have found the human repertoire to be smaller
than expected due to a reduced cyclophilin repertoire. We show here that whilst the
members of the cyclophilin family (which are predominantly found in the nucleus
and cytoplasm) and the parvulin family (which are predominantly nuclear) are
largely conserved between different repertoires, the FKBPs (which are predominantly
found in the cytoplasm and endoplasmic reticulum) are not. It therefore appears
that the cyclophilins and parvulins have evolved to perform conserved functions,
while the FKBPs have evolved to fill ever-changing niches within the constantly
evolving organisms. Many orthologous subgroups within the different PPIase families
appear to have evolved from a distinct common ancestor, whereas others, such as the
mitochondrial cyclophilins, appear to have evolved independently of one another. We
have also identified a novel parvulin within Drosophila melanogaster that is unique to
the fruit fly, indicating a recent evolutionary emergence. Interestingly, the fission yeast
repertoire, which contains no unique cyclophilins and parvulins, shares no PPIases
solely with the budding yeast but it does share a majority with the higher eukaryotes
in this study, unlike the budding yeast. It therefore appears that, in comparison with
Schizosaccharomyces pombe, Saccharomyces cerevisiae is a poor representation of the
higher eukaryotes for the study of PPIases.
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Affiliation(s)
- Trevor J Pemberton
- The Brighton and Sussex Medical School, University of Sussex, Falmer, Brighton ,East Sussex BN1 9PX, United Kingdom.
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7
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Kromina KA, Ignatov AN, Abdeeva IA. Role of peptidyl-prolyl-cis/trans-isomerases in pathologic processes. BIOCHEMISTRY MOSCOW SUPPLEMENT SERIES A-MEMBRANE AND CELL BIOLOGY 2008. [DOI: 10.1134/s199074780803001x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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8
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Wildemann D, Hernandez Alvarez B, Stoller G, Zhou XZ, Lu KP, Erdmann F, Ferrari D, Fischer G. An essential role for Pin1 in Xenopus laevis embryonic development revealed by specific inhibitors. Biol Chem 2008; 388:1103-11. [PMID: 17937625 DOI: 10.1515/bc.2007.127] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The peptidyl prolyl cis/trans isomerase (PPIase) Pin1 plays an important role in phosphorylation-dependent events of the cell cycle. This function is linked to its display of two phosphothreonine/phosphoserine-proline binding motifs, one within the type IV WW domain and a second within the parvulin-like catalytic domain. By microinjection of the compound Ac-Phe-D-Thr(PO3H2)-Pip-Nal-Gln-NH2, which inhibits Xenopus laevis Pin1 with a Ki value of 19.4+/-1.5 nM, into the animal pole of X. laevis embryos at the two-cell stage, the impact of Pin1 PPIase activity on cell cycle progression and embryonic development could be analysed, independent of WW domain-mediated phosphoprotein binding. Injected embryos showed a dramatically decreased survival rate at late stages of development that could only be partially compensated by co-injection with mRNAs of enzymatically active Pin1 variants, demonstrating that the phosphorylation-specific PPIase activity of Pin1 is essential for cell division and development in X. laevis.
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Affiliation(s)
- Dirk Wildemann
- Max Planck Research Unit for Enzymology of Protein Folding, Weinbergweg 22, D-06120 Halle/Saale, Germany
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9
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Abstract
PIN1 is a peptidyl-prolyl isomerase that can alter the conformation of phosphoproteins and so affect protein function and/or stability. PIN1 regulates a number of proteins important for cell-cycle progression and, based on gain- and loss-of-function studies, is presumed to operate as a molecular timer of this important process. Therefore, it seems logical that alterations in the level of PIN1 can influence hyperproliferative diseases such as cancer. However, the precise role of PIN1 in cancer remains controversial.
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Affiliation(s)
- Elizabeth S Yeh
- Department of Cancer Biology, Abramson Family Cancer Research Institute, University of Pennsylvania, 421 Curie Boulevard, Philadelphia, PA 19104-6160, USA
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10
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Laxa M, König J, Dietz KJ, Kandlbinder A. Role of the cysteine residues in Arabidopsis thaliana cyclophilin CYP20-3 in peptidyl-prolyl cis-trans isomerase and redox-related functions. Biochem J 2007; 401:287-97. [PMID: 16928193 PMCID: PMC1698676 DOI: 10.1042/bj20061092] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Cyps (cyclophilins) are ubiquitous proteins of the immunophilin superfamily with proposed functions in protein folding, protein degradation, stress response and signal transduction. Conserved cysteine residues further suggest a role in redox regulation. In order to get insight into the conformational change mechanism and functional properties of the chloroplast-located CYP20-3, site-directed mutagenized cysteine-->serine variants were generated and analysed for enzymatic and conformational properties under reducing and oxidizing conditions. Compared with the wild-type form, elimination of three out of the four cysteine residues decreased the catalytic efficiency of PPI (peptidyl-prolyl cis-trans isomerase) activity of the reduced CYP20-3, indicating a regulatory role of dithiol-disulfide transitions in protein function. Oxidation was accompanied by conformational changes with a predominant role in the structural rearrangement of the disulfide bridge formed between Cys(54) and Cys(171). The rather negative E(m) (midpoint redox potential) of -319 mV places CYP20-3 into the redox hierarchy of the chloroplast, suggesting the activation of CYP20-3 in the light under conditions of limited acceptor availability for photosynthesis as realized under environmental stress. Chloroplast Prx (peroxiredoxins) were identified as interacting partners of CYP20-3 in a DNA-protection assay. A catalytic role in the reduction of 2-Cys PrxA and 2-Cys PrxB was assigned to Cys(129) and Cys(171). In addition, it was shown that the isomerization and disulfide-reduction activities are two independent functions of CYP20-3 that both are regulated by the redox state of its active centre.
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Affiliation(s)
- Miriam Laxa
- *Biochemistry and Physiology of Plants, Faculty of Biology, W5, Bielefeld University, 33501 Bielefeld, Germany
| | - Janine König
- *Biochemistry and Physiology of Plants, Faculty of Biology, W5, Bielefeld University, 33501 Bielefeld, Germany
- †Division of Biological Chemistry and Molecular Microbiology, The Wellcome Trust Biocentre, University of Dundee, Dundee DD1 5EH, U.K
| | - Karl-Josef Dietz
- *Biochemistry and Physiology of Plants, Faculty of Biology, W5, Bielefeld University, 33501 Bielefeld, Germany
- To whom correspondence should be addressed (email )
| | - Andrea Kandlbinder
- *Biochemistry and Physiology of Plants, Faculty of Biology, W5, Bielefeld University, 33501 Bielefeld, Germany
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11
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Behrsin CD, Bailey ML, Bateman KS, Hamilton KS, Wahl LM, Brandl CJ, Shilton BH, Litchfield DW. Functionally Important Residues in the Peptidyl-prolyl Isomerase Pin1 Revealed by Unigenic Evolution. J Mol Biol 2007; 365:1143-62. [PMID: 17113106 DOI: 10.1016/j.jmb.2006.10.078] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2006] [Revised: 10/20/2006] [Accepted: 10/24/2006] [Indexed: 01/23/2023]
Abstract
Pin1 is a phosphorylation-dependent member of the parvulin family of peptidyl-prolyl isomerases exhibiting functional conservation between yeast and man. To perform an unbiased analysis of the regions of Pin1 essential for its functions, we generated libraries of randomly mutated forms of the human Pin1 cDNA and identified functional Pin1 alleles by their ability to complement the Pin1 homolog Ess1 in Saccharomyces cerevisiae. We isolated an extensive collection of functional mutant Pin1 clones harboring a total of 356 amino acid substitutions. Surprisingly, many residues previously thought to be critical in Pin1 were found to be altered in this collection of functional mutants. In fact, only 17 residues were completely conserved in these mutants and in Pin1 sequences from other eukaryotic organisms, with only two of these conserved residues located within the WW domain of Pin1. Examination of invariant residues provided new insights regarding a phosphate-binding loop that distinguishes a phosphorylation-dependent peptidyl-prolyl isomerase such as Pin1 from other parvulins. In addition, these studies led to an investigation of residues involved in catalysis including C113 that was previously implicated as the catalytic nucleophile. We demonstrate that substitution of C113 with D does not compromise Pin1 function in vivo nor does this substitution abolish catalytic activity in purified recombinant Pin1. These findings are consistent with the prospect that the function of residue 113 may not be that of a nucleophile, thus raising questions about the model of nucleophilic catalysis. Accordingly, an alternative catalytic mechanism for Pin1 is postulated.
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Affiliation(s)
- C D Behrsin
- Department of Biochemistry, University of Western Ontario, London, Ontario, Canada N6A 5C1
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12
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Abstract
Designed peptidyl-prolyl isomerase (PPIase) inhibitors of Pin1, cyclophilin (CyP), and FK506 binding protein (FKBP) are reviewed. Emphasis is placed on the design, structure, and biological activity of the inhibitors. While CyP and FKBP inhibitors have been explored fairly thoroughly, inhibitors of the relatively new Pin1 cell cycle regulator are in their infancy. Ligands designed for Pin1 and CyP have primarily been ground state analogues: alkenes and bicyclic compounds. For FKBP, more of the focus has been on analogues of bonds at the reactive center, the prolyl amide, because of the idea that the alpha-ketoamide of FK506 is an analogue of the twisted amide in the transition state.
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Affiliation(s)
- Xiaodong J Wang
- Department of Chemistry, Virginia Tech, Blacksburg, VA 24060, USA
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13
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Fujiyama S, Yanagida M, Hayano T, Miura Y, Isobe T, Fujimori F, Uchida T, Takahashi N. Isolation and proteomic characterization of human Parvulin-associating preribosomal ribonucleoprotein complexes. J Biol Chem 2002; 277:23773-80. [PMID: 11960984 DOI: 10.1074/jbc.m201181200] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Human parvulin (hParvulin; Par14/EPVH) belongs to the third family of peptidylprolyl cis-trans isomerases that exhibit an enzymatic activity of interconverting the cis-trans conformation of the prolyl peptide bond, and shows sequence similarity to the regulator enzyme for cell cycle transitions, human Pin1. However, the cellular function of hParvulin is entirely unknown. Here, we demonstrate that hParvulin associates with the preribosomal ribonucleoprotein (pre-rRNP) complexes, which contain preribosomal RNAs, at least 26 ribosomal proteins, and 26 trans-acting factors involved in rRNA processing and assembly at an early stage of ribosome biogenesis. Since an amino-terminal domain of hParvulin, which is proposed to be a putative DNA-binding domain, was alone sufficient to associate in principle with the pre-rRNP complexes, the association is probably through protein-RNA interaction. In addition, hParvulin co-precipitated at least 10 proteins not previously known to be involved in ribosome biogenesis. Coincidentally, most of these proteins are implicated in regulation of microtubule assembly or nucleolar reformation during the mitotic phase of the cell. Thus, these results, coupled with the preferential nuclear localization of hParvulin, suggest that hParvulin may be involved in ribosome biogenesis and/or nucleolar re-assembly of mammalian cells.
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Affiliation(s)
- Sally Fujiyama
- Department of Biotechnology, United Graduate School of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu-shi, Tokyo 183-8509, Japan
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14
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Abstract
Peptidyl-prolyl isomerases (PPIs) catalyse the cis-trans isomerisation of peptide bonds N-terminal to proline residues in polypeptide chains. They have roles in the folding of newly synthesised proteins and in the function of the immune system. In addition, members of the parvulin-like family of PPIs have been implicated in cell cycle control. Their activity is directed by the prior phosphorylation of target proteins in both yeast and mammalian cells. More recent data have illustrated that they may also influence other nuclear events. This review examines PPI activity in the context of eukaryotic transcriptional regulation. The findings are consistent with a two-step model of conformational control, in which the outcome depends on the transcription factor involved.
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Affiliation(s)
- Peter E Shaw
- School of Biomedical Sciences and Institute of Cell Signalling, University of Nottingham, Queen's Medical Centre, Nottingham NG7 2UH, UK.
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15
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Xu GM, Arnaout MA. WAC, a novel WW domain-containing adapter with a coiled-coil region, is colocalized with splicing factor SC35. Genomics 2002; 79:87-94. [PMID: 11827461 DOI: 10.1006/geno.2001.6684] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
WW domains mediate protein-protein interactions in many intracellular processes. In pre-mRNA splicing, WW domains participate in cross-intron bridging. These WW domains are characterized by a central aromatic block of three tyrosine residues. We identified a novel protein containing the same type of WW domain. The gene encoding the protein, named WAC, is located in human chromosome 10p11.2-10p12.1. A Drosophila melanogaster WAC homolog (CG8949) was identified as a Rosetta stone protein. Domain fusion analysis of the Rosetta stone protein linked WAC to splicing factor SNRP70. WAC existed mainly in a tyrosine-phosphorylated form. Immunofluorescence analysis colocalized WAC with SC35, the marker for pre-mRNA splicing machinery. Our analysis suggests that WAC represents a novel member of WW-domain-containing proteins for RNA processing.
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Affiliation(s)
- G Mark Xu
- Polycystic Kidney Disease Program, Renal Unit, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129, USA.
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16
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Devasahayam G, Chaturvedi V, Hanes SD. The Ess1 prolyl isomerase is required for growth and morphogenetic switching in Candida albicans. Genetics 2002; 160:37-48. [PMID: 11805043 PMCID: PMC1461953 DOI: 10.1093/genetics/160.1.37] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Prolyl-isomerases (PPIases) are found in all organisms and are important for the folding and activity of many proteins. Of the 13 PPIases in Saccharomyces cerevisiae only Ess1, a parvulin-class PPIase, is essential for growth. Ess1 is required to complete mitosis, and Ess1 and its mammalian homolog, Pin1, interact directly with RNA polymerase II. Here, we isolate the ESS1 gene from the pathogenic fungus Candida albicans and show that it is functionally homologous to the S. cerevisiae ESS1. We generate conditional-lethal (ts) alleles of C. albicans ESS1 and use these mutations to demonstrate that ESS1 is essential for growth in C. albicans. We also show that reducing the dosage or activity of ESS1 blocks morphogenetic switching from the yeast to the hyphal and pseudohyphal forms under certain conditions. Analysis of double mutants of ESS1 and TUP1 or CPH1, two genes known to be involved in morphogenetic switching, suggests that ESS1 functions in the same pathway as CPH1 and upstream of or in parallel to TUP1. Given that switching is important for virulence of C. albicans, inhibitors of Ess1 might be useful as antifungal agents.
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Affiliation(s)
- Gina Devasahayam
- Molecular Genetics Program, Wadsworth Center, New York State Department of Health, Albany, New York 12208, USA
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17
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Fujimori F, Gunji W, Kikuchi J, Mogi T, Ohashi Y, Makino T, Oyama A, Okuhara K, Uchida T, Murakami Y. Crosstalk of prolyl isomerases, Pin1/Ess1, and cyclophilin A. Biochem Biophys Res Commun 2001; 289:181-90. [PMID: 11708797 DOI: 10.1006/bbrc.2001.5925] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Previous studies have indicated that Ess1/Pin1, a gene in the parvulin family of peptidyl-prolyl isomerases (PPIases), plays an important role in regulating the G(2)/M transition of the cell cycle by binding cell-cycle-regulating proteins in eukaryotic cells. Although the ess1 gene has been considered to be essential in yeast, we have isolated viable ess1 deletion mutants and demonstrated, via analysis of yeast gene expression profiles using microarray techniques, a novel regulatory role for ESS1 in the G(1) phase. Although the overall expression profiles in the tested strains (C110-1, W303, S288c, and RAY-3AD) were similar, marked changes were detected for a number of genes involved in the molecular action of ESS1. Among these, the expression levels of a cyclophilin A gene, also a member of the PPIase family, increased in the ess1 null mutant derived from C110-1. Subsequent treatment with cyclosporin A significantly retarded growth, which suggests that ESS1 and cyclophilin A are functionally linked in yeast cells and play important roles at the G(1) phase of the cell cycle.
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Affiliation(s)
- F Fujimori
- Department of Biological Science & Technology, Faculty of Industrial Science & Technology, Science University of Tokyo, Japan
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18
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Ideno A, Yoshida T, Iida T, Furutani M, Maruyama T. FK506-binding protein of the hyperthermophilic archaeum, Thermococcus sp. KS-1, a cold-shock-inducible peptidyl-prolyl cis-trans isomerase with activities to trap and refold denatured proteins. Biochem J 2001; 357:465-71. [PMID: 11439096 PMCID: PMC1221973 DOI: 10.1042/0264-6021:3570465] [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: 11/17/2022]
Abstract
The FK506 (tacrolimus)-binding protein (FKBP) type peptidyl-prolyl cis-trans isomerase (PPIase) in the hyperthermophilic archaeum Thermococcus sp. KS-1 was shown to be induced by temperature downshift to growth temperatures lower than the optimum. This PPIase (TcFKBP18) showed chaperone-like protein refolding activity in addition to PPIase activity in vitro. It refolded unfolded citrate synthase (CS) and increased the yield of the refolded protein. At a molar ratio of 15:1 ([TcFKBP18] to [CS]) in the refolding mixture, the recovered yield of folded CS was maximal at 62%, whereas that of spontaneous refolding was 11%. Increasing FKBP above a 15:1 ratio decreased the final yield, whereas the aggregation of unfolded CS was suppressed. A cross-linking analysis showed the formation of a complex between TcFKBP18 and unfolded CS (1:1 complex) at molar ratios of 3:1 to 15:1. However, molar ratios of 15:1 or 60:1 induced the binding of multiple FKBP molecules to an unfolded CS molecule (multimeric complex). Disrupting hydrophobic interaction by adding ethylene glycol at a molar ratio of 60:1 ([TcFKBP18] to [CS]) suppressed the formation of this multimeric complex, simultaneously enhancing CS refolding. FK506 also suppressed the formation of the multimeric complex while increasing the chaperone-like activity. These results suggest that the hydrophobic region of TcFKBP18, probably the FK506-binding pocket, was important for the interaction with unfolded proteins. No cross-linked product was detected between TcFKBP18 and native dimeric CS. TcFKBP18 probably traps the unfolded protein, then refolds and releases it in a native form. This FKBP might be important at growth temperatures lower than the optimum in Thermococcus sp. KS-1 cells.
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Affiliation(s)
- A Ideno
- Marine Biotechnology Institute Co. Ltd., 3-75-1 Heita, Kamaishi, Iwate 026-0001, Japan.
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19
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Hsu T, McRackan D, Vincent TS, Gert de Couet H. Drosophila Pin1 prolyl isomerase Dodo is a MAP kinase signal responder during oogenesis. Nat Cell Biol 2001; 3:538-43. [PMID: 11389437 DOI: 10.1038/35078508] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The mammalian cis-trans prolyl isomerase Pin1 and its yeast orthologue Ess1/Ptf1 have been implicated in cell cycle control but a correlation between biochemical and physiological functions has not been established conclusively. Pin1 targets the proline residue carboxy-terminal to the phosphorylated threonine or serine residue, which constitutes part of the phosphorylated mitogen-activated protein kinase (MAPK) site PXpT/SP. Here we show that the Drosophila Pin1 homologue, the Dodo protein, is involved in dorsoventral patterning of the follicular epithelium in the egg chamber. Its function is to facilitate the degradation of transcription factor CF2, which requires, a priori, activated epidermal growth factor receptor-MAPK signalling.
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Affiliation(s)
- T Hsu
- Laboratory of Cancer Genomics, Hollings Cancer Center, Medical University of South Carolina, 86 Jonathan Lucas Street, Charleston, South Carolina 29425, USA.
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20
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21
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Metzner M, Stoller G, Rücknagel KP, Lu KP, Fischer G, Luckner M, Küllertz G. Functional replacement of the essential ESS1 in yeast by the plant parvulin DlPar13. J Biol Chem 2001; 276:13524-9. [PMID: 11118437 DOI: 10.1074/jbc.m007005200] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
A functionally Pin1-like peptidyl-prolyl cis/trans isomerase (PPIase(1)) was isolated from proembryogenic masses (PEMs) of Digitalis lanata according to its enzymatic activity. Partial sequence analysis of the purified enzyme (DlPar13) revealed sequence homology to members of the parvulin family of PPIases. Similar to human Pin1 and yeast Ess1, it exhibits catalytic activity toward substrates containing (Thr(P)/Ser(P))-Pro peptide bonds and comparable inhibition kinetics with juglone. Unlike Pin1-type enzymes it lacks the phosphoserine or phosphothreonine binding WW domain. Western blotting with anti-DlPar13 serum recognized the endogenous form in nucleic and cytosolic fractions of the plant cells. Since the PIN1 homologue ESS1 is an essential gene, complementation experiments in yeast were performed. When overexpressed in Saccharomyces cerevisiae DlPar13 is almost as effective as hPin1 in rescuing the temperature-sensitive phenotype caused by a mutation in ESS1. In contrast, the human parvulin hPar14 is not able to rescue the lethal phenotype of this yeast strain at nonpermissive temperatures. These results suggest a function for DlPar13 rather similar to parvulins of the Pin1-type.
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Affiliation(s)
- M Metzner
- Institut für Pharmazeutische Biologie, Martin-Luther-Universität Halle-Wittenberg, Hoher Weg 8, D-06120 Halle/Saale, Germany
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22
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Chao SH, Greenleaf AL, Price DH. Juglone, an inhibitor of the peptidyl-prolyl isomerase Pin1, also directly blocks transcription. Nucleic Acids Res 2001; 29:767-73. [PMID: 11160900 PMCID: PMC30403 DOI: 10.1093/nar/29.3.767] [Citation(s) in RCA: 118] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The C-terminal domain (CTD) of the large subunit of RNA polymerase II plays a role in transcription and RNA processing. Yeast ESS1, a peptidyl-prolyl cis/trans isomerase, is involved in RNA processing and can associate with the CTD. Using several types of assays we could not find any evidence of an effect of Pin1, the human homolog of ESS1, on transcription by RNA polymerase II in vitro or on the expression of a reporter gene in vivo. However, an inhibitor of Pin1, 5-hydroxy-1,4-naphthoquinone (juglone), blocked transcription by RNA polymerase II. Unlike N-ethylmaleimide, which inhibited all phases of transcription by RNA polymerase II, juglone disrupted the formation of functional preinitiation complexes by modifying sulfhydryl groups but did not have any significant effect on either initiation or elongation. Both RNA polymerases I and III, but not T7 RNA polymerase, were inhibited by juglone. The primary target of juglone has not been unambiguously identified, although a site on the polymerase itself is suggested by inhibition of RNA polymerase II during factor-independent transcription of single-stranded DNA. Because of its unique inhibitory properties juglone should prove useful in studying transcription in vitro.
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Affiliation(s)
- S H Chao
- Molecular Biology Program, University of Iowa, Iowa City, IA 52242, USA
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23
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Sekerina E, Rahfeld JU, Müller J, Fanghänel J, Rascher C, Fischer G, Bayer P. NMR solution structure of hPar14 reveals similarity to the peptidyl prolyl cis/trans isomerase domain of the mitotic regulator hPin1 but indicates a different functionality of the protein. J Mol Biol 2000; 301:1003-17. [PMID: 10966801 DOI: 10.1006/jmbi.2000.4013] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The 131-amino acid residue parvulin-like human peptidyl-prolyl cis/trans isomerase (PPIase) hPar14 was shown to exhibit sequence similarity to the regulator enzyme for cell cycle transitions human hPin1, but specificity for catalyzing pSer(Thr)-Pro cis/trans isomerizations was lacking. To determine the solution structure of hPar14 the (1)H, (13)C, and (15)N chemical shifts of this protein have been assigned using heteronuclear two and three-dimensional NMR experiments on unlabeled and uniformly (15)N/(13)C-labeled recombinant protein isolated from Escherichia coli cells that overexpress the protein. The chemical shift assignments were used to interpret the NOE data, which resulted in a total of 1042 NOE restraints. The NOE restraints were used along with 71 dihedral angle restraints and 38 hydrogen bonding restraints to produce 50 low-energy structures. The hPar14 folds into a betaalpha(3)betaalphabeta(2) structure, and contains an unstructured 35-amino acid basic tail N-terminal to the catalytic core that replaces the WW domain of hPin1 homologs. The three-dimensional structures of hPar14 and the PPIase domain of human hPin1 reveal a high degree of conservation. The root-mean-square deviations of the mean atomic coordinates of the heavy atoms of the backbone between residues 38 to 45, 50 to 58, 64 to 70, 81 to 86, 115 to 119 and 122 to 128 of hPar14 were 0.81(+/-0.07) A. The hPar14 model structure provides insight into how this class of PPIases may select preferential secondary catalytic sites, and also allows identification of a putative DNA-binding motif in parvulin-like PPIases.
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Affiliation(s)
- E Sekerina
- Max-Planck-Stelle for Enzymology of Protein Folding, 06120 Halle/Saale, Weinberg 22, Germany
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24
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Pancio HA, Vander Heyden N, Ratner L. The C-terminal proline-rich tail of human immunodeficiency virus type 2 Vpx is necessary for nuclear localization of the viral preintegration complex in nondividing cells. J Virol 2000; 74:6162-7. [PMID: 10846100 PMCID: PMC112115 DOI: 10.1128/jvi.74.13.6162-6167.2000] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Human immunodeficiency virus type 2 (HIV-2), like other lentiviruses, is capable of infecting nondividing T cells and macrophages. The present work shows that in HIV-2-infected cells, Vpx is necessary for efficient nuclear import of the preintegration complex. In agreement with this finding, the subcellular localization of a GFP-Vpx fusion protein was found to be predominantly nuclear. However, deletion of the proline-rich C-terminal 11 residues of Vpx resulted in a shift of the fusion protein to the cytoplasm. Furthermore, the same deletion in the context of the provirus resulted in a decrease in nuclear import of the preintegration complex and attenuated replication in macrophages.
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Affiliation(s)
- H A Pancio
- Departments of Medicine, Pathology, and Molecular Microbiology, Washington University School of Medicine, St. Louis, MO 63110, USA
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25
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Ideno A, Yoshida T, Furutani M, Maruyama T. The 28.3 kDa FK506 binding protein from a thermophilic archaeum, Methanobacterium thermoautotrophicum, protects the denaturation of proteins in vitro. EUROPEAN JOURNAL OF BIOCHEMISTRY 2000; 267:3139-49. [PMID: 10824098 DOI: 10.1046/j.1432-1327.2000.01332.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Two families of FK506 binding protein (FKBP) type peptidyl-prolyl cis-trans isomerase (PPIase) have been found in Archaea. One is the 16-18 kDa short type FKBP family, and another is the 26-30 kDa long type FKBP family. The latter has a longer C-terminal region than the former. In this study, the 28.3 kDa long type FKBP gene from a thermophilic archaeum, Methanobacterium thermoautotrophicum, was expressed in Escherichia coli, and its gene product (MbFK) was characterized. The PPIase activity of MbFK was much lower than those of other FKBPs reported against oligopeptidyl substrates. MbFK protected green fluorescent protein (GFP) and rhodanese from thermal denaturation. Furthermore, MbFK suppressed the aggregation of chemically unfolded rhodanese and elevated the yield of its refolding although this activity was weaker than that of GroEL/ES. We made two deletion mutants, MbFK-N which lacked the C-terminal region, and MbFK-C which had only the C-terminal region. Far-UV CD spectra of these mutants showed that their secondary structures did not change from that of the wild-type. Whereas the PPIase activity of MbFK-N was low but detectable, that of MbFK-C was undetectable. The MbFK-C protected the thermal protein aggregation, and possessed a weak but significant aggregation suppressing activity against chemically unfolded protein. However, the MbFK-N did not suppress the aggregation of chemically unfolded rhodanese while it protected heat induced aggregation of rhodanese. These results may indicate that aggregation suppressing activity of MbFK-W against chemically unfolded protein are exerted mainly by its C-terminal domain while both domains contribute to thermal protein aggregation suppression.
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Affiliation(s)
- A Ideno
- Marine Biotechnology Institute Co., Ltd, Kamaishi, Iwate, Japan; Sekisui Chemical Co., Ltd, Minase Research Institute, Osaka, Japan.
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26
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Abstract
The tetratricopeptide repeat (TPR) motif is a protein-protein interaction module found in multiple copies in a number of functionally different proteins that facilitates specific interactions with a partner protein(s). Three-dimensional structural data have shown that a TPR motif contains two antiparallel alpha-helices such that tandem arrays of TPR motifs generate a right-handed helical structure with an amphipathic channel that might accommodate the complementary region of a target protein. Most TPR-containing proteins are associated with multiprotein complexes, and there is extensive evidence indicating that TPR motifs are important to the functioning of chaperone, cell-cycle, transcription, and protein transport complexes. The TPR motif may represent an ancient protein-protein interaction module that has been recruited by different proteins and adapted for specific functions. BioEssays 1999;21:932-939.
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Affiliation(s)
- G L Blatch
- Protein-Structure-Function Research Programme, Department of Cell Biology, University of the Witwatersrand, Johannesburg, South Africa
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27
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Abstract
The tetratricopeptide repeat (TPR) motif is a protein-protein interaction module found in multiple copies in a number of functionally different proteins that facilitates specific interactions with a partner protein(s). Three-dimensional structural data have shown that a TPR motif contains two antiparallel alpha-helices such that tandem arrays of TPR motifs generate a right-handed helical structure with an amphipathic channel that might accommodate the complementary region of a target protein. Most TPR-containing proteins are associated with multiprotein complexes, and there is extensive evidence indicating that TPR motifs are important to the functioning of chaperone, cell-cycle, transcription, and protein transport complexes. The TPR motif may represent an ancient protein-protein interaction module that has been recruited by different proteins and adapted for specific functions. BioEssays 1999;21:932-939.
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Affiliation(s)
- G L Blatch
- Protein-Structure-Function Research Programme, Department of Cell Biology, University of the Witwatersrand, Johannesburg, South Africa
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28
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Rulten S, Thorpe J, Kay J. Identification of eukaryotic parvulin homologues: a new subfamily of peptidylprolyl cis-trans isomerases. Biochem Biophys Res Commun 1999; 259:557-62. [PMID: 10364457 DOI: 10.1006/bbrc.1999.0828] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We report here the existence of a subfamily of eukaryotic parvulin proteins that have strong sequence homology with E. coli parvulin, but lack the WW domain found in previously described eukarytoic parvulins. We hence term members of this subfamily EPVH (eukaryotic parvulin homologue). We describe the characterisation of hEPVH (human eukaryotic parvulin homologue). Immunogold labelling transmission electron microscopy reveals that hEPVH is preferentially localised in the mitochondrial matrix. The homology of hEPVH with its prokaryotic ancestor supports the hypothesis that this protein may have a mitochondrial function. An essential role in this organelle may explain the need for a high degree of conservation of this protein between distantly related species.
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Affiliation(s)
- S Rulten
- Department of Biological Sciences, University of Sussex, Falmer, Brighton, BN1 9QG, United Kingdom
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29
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Hani J, Schelbert B, Bernhardt A, Domdey H, Fischer G, Wiebauer K, Rahfeld JU. Mutations in a peptidylprolyl-cis/trans-isomerase gene lead to a defect in 3'-end formation of a pre-mRNA in Saccharomyces cerevisiae. J Biol Chem 1999; 274:108-16. [PMID: 9867817 DOI: 10.1074/jbc.274.1.108] [Citation(s) in RCA: 87] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
In a genetic screen aimed at the identification of trans-acting factors involved in mRNA 3'-end processing of budding yeast, we have previously isolated two temperature-sensitive mutants with an apparent defect in the 3'-end formation of a plasmid-derived pre-mRNA. Surprisingly, both mutants were rescued by the essential gene ESS1/PTF1 that encoded a putative peptidylprolyl-cis/trans-isomerase (PPIase) (Hani, J., Stumpf, G., and Domdey, H. (1995) FEBS Lett. 365, 198-202). Such enzymes, which catalyze the cis/trans-interconversion of peptide bonds N-terminal of prolines, are suggested to play a role in protein folding or trafficking. Here we report that Ptf1p shows PPIase activity in vitro, displaying an unusual substrate specificity for peptides with phosphorylated serine and threonine residues preceding proline. Both mutations were found to result in amino acid substitutions of highly conserved residues within the PPIase domain, causing a marked decrease in PPIase activity of the mutant enzymes. Our results are suggestive of a so far unknown involvement of a PPIase in mRNA 3'-end formation in Saccharomyces cerevisiae.
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Affiliation(s)
- J Hani
- Genzentrum der Ludwig-Maximilians-Universität München, Feodor-Lynen Strasse 25, 81377 München, Germany
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30
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Abstract
Cloning of the Huntington's disease gene uncovered huntingtin, which is remarkable for its lack of similarity with known proteins despite its large size, approximately 350 kDa. Subsequent experiments established that huntingtin has an as yet unknown function, crucial for embryonic development and neurogenesis. Recent protein trapping to identify huntingtin interactors now reveals that many different prey fall victim to huntingtin bait.
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Affiliation(s)
- J F Gusella
- Molecular Neurogenetics Unit, Massachusetts General Hospital, Charlestown 02129, USA.
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31
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Maleszka R, de Couet HG, Miklos GL. Data transferability from model organisms to human beings: insights from the functional genomics of the flightless region of Drosophila. Proc Natl Acad Sci U S A 1998; 95:3731-6. [PMID: 9520435 PMCID: PMC19905 DOI: 10.1073/pnas.95.7.3731] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
At what biological levels are data from single-celled organisms akin to a Rosetta stone for multicellular ones? To examine this question, we characterized a saturation-mutagenized 67-kb region of the Drosophila genome by gene deletions, transgenic rescues, phenotypic dissections, genomic and cDNA sequencing, bio-informatic analysis, reverse transcription-PCR studies, and evolutionary comparisons. Data analysis using cDNA/genomic DNA alignments and bio-informatic algorithms revealed 12 different predicted proteins, most of which are absent from bacterial databases, half of which are absent from Saccharomyces cerevisiae, and nearly all of which have relatives in Caenorhabditis elegans and Homo sapiens. Gene order is not evolutionarily conserved; the closest relatives of these genes are scattered throughout the yeast, nematode, and human genomes. Most gene expression is pleiotropic, and deletion studies reveal that a morphological phenotype is seldom observed when these genes are removed from the genome. These data pinpoint some general bottlenecks in functional genomics, and they reveal the acute emerging difficulties with data transferability above the levels of genes and proteins, especially with complex human phenotypes. At these higher levels the Rosetta stone analogy has almost no applicability. However, newer transgenic technologies in Drosophila and Mus, combined with coherency pattern analyses of gene networks, and synthetic neural modeling, offer insights into organismal function. We conclude that industrially scaled robogenomics in model organisms will have great impact if it can be realistically linked to epigenetic analyses of human variation and to phenotypic analyses of human diseases in different genetic backgrounds.
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Affiliation(s)
- R Maleszka
- Research School of Biological Sciences, Australian National University, Canberra ACT 2600, Australia
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