1
|
Shin G, Lim SI. Site-specific proximity ligation provides molecular insights into biologically relevant interfaces of protein-protein interaction. Biochem Biophys Res Commun 2020; 533:932-937. [PMID: 33008597 DOI: 10.1016/j.bbrc.2020.09.097] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Revised: 09/10/2020] [Accepted: 09/23/2020] [Indexed: 11/30/2022]
Abstract
Dynamic protein-protein interactions (PPIs) are fundamental to spatiotemporal control of protein functions in biological systems. Dissecting binding interfaces in aqueous solution (i.e., biological interfaces) is of great importance for identifying molecular determinants that contribute to the affinity and specificity of PPIs. Herein, we describe a biochemical method, termed site-specific proximity ligation (SPL), that enables the identification and reconstruction of native binding interfaces distinct from those present in crystal structures and models from computational prediction. SPL involves the strategic incorporation of an aryl azide-containing unnatural amino acid (AZF) into residues of interest in a particular protein that forms a multiprotein complex. Depending on the interfacial role of a targeted residue, a photo-inducible highly reactive incorporated AZF moiety may react with neighboring functional groups to covalently capture an otherwise non-covalent or weak interaction with a specific partner protein, thereby revealing the landscape of biological interfaces. Using a heterotrimeric nuclear pore protein as a model, we show that the biological interfaces of the complex mapped by SPL provide new insight into dynamic molecular recognition that is missed by, or even in conflict with, static models.
Collapse
Affiliation(s)
- Goeun Shin
- Department of Chemical Engineering, Pukyong National University, Yongso-ro 45, Nam-gu, Busan, Republic of Korea
| | - Sung In Lim
- Department of Chemical Engineering, Pukyong National University, Yongso-ro 45, Nam-gu, Busan, Republic of Korea.
| |
Collapse
|
2
|
Palopoli N, Marchetti J, Monzon AM, Zea DJ, Tosatto SCE, Fornasari MS, Parisi G. Intrinsically Disordered Protein Ensembles Shape Evolutionary Rates Revealing Conformational Patterns. J Mol Biol 2020; 433:166751. [PMID: 33310020 DOI: 10.1016/j.jmb.2020.166751] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Revised: 12/01/2020] [Accepted: 12/05/2020] [Indexed: 10/22/2022]
Abstract
Intrinsically disordered proteins (IDPs) lack stable tertiary structure under physiological conditions. The unique composition and complex dynamical behaviour of IDPs make them a challenge for structural biology and molecular evolution studies. Using NMR ensembles, we found that IDPs evolve under a strong site-specific evolutionary rate heterogeneity, mainly originated by different constraints derived from their inter-residue contacts. Evolutionary rate profiles correlate with the experimentally observed conformational diversity of the protein, allowing the description of different conformational patterns possibly related to their structure-function relationships. The correlation between evolutionary rates and contact information improves when structural information is taken not from any individual conformer or the whole ensemble, but from combining a limited number of conformers. Our results suggest that residue contacts in disordered regions constrain evolutionary rates to conserve the dynamic behaviour of the ensemble and that evolutionary rates can be used as a proxy for the conformational diversity of IDPs.
Collapse
Affiliation(s)
- Nicolas Palopoli
- Departamento de Ciencia y Tecnología, Universidad Nacional de Quilmes, CONICET, Bernal, Buenos Aires, Argentina
| | - Julia Marchetti
- Departamento de Ciencia y Tecnología, Universidad Nacional de Quilmes, CONICET, Bernal, Buenos Aires, Argentina
| | | | - Diego J Zea
- Sorbonne Université, CNRS, IBPS, Laboratoire de Biologie Computationnelle et Quantitative (LCQB), Paris, France
| | | | - Maria S Fornasari
- Departamento de Ciencia y Tecnología, Universidad Nacional de Quilmes, CONICET, Bernal, Buenos Aires, Argentina
| | - Gustavo Parisi
- Departamento de Ciencia y Tecnología, Universidad Nacional de Quilmes, CONICET, Bernal, Buenos Aires, Argentina.
| |
Collapse
|
3
|
Understanding serine proteases implications on Leishmania spp lifecycle. Exp Parasitol 2018; 184:67-81. [DOI: 10.1016/j.exppara.2017.11.008] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2017] [Revised: 11/14/2017] [Accepted: 11/20/2017] [Indexed: 12/14/2022]
|
4
|
Abstract
Exchange of macromolecules between the nucleus and cytoplasm is a key regulatory event in the expression of a cell's genome. This exchange requires a dedicated transport system: (1) nuclear pore complexes (NPCs), embedded in the nuclear envelope and composed of proteins termed nucleoporins (or "Nups"), and (2) nuclear transport factors that recognize the cargoes to be transported and ferry them across the NPCs. This transport is regulated at multiple levels, and the NPC itself also plays a key regulatory role in gene expression by influencing nuclear architecture and acting as a point of control for various nuclear processes. Here we summarize how the yeast Saccharomyces has been used extensively as a model system to understand the fundamental and highly conserved features of this transport system, revealing the structure and function of the NPC; the NPC's role in the regulation of gene expression; and the interactions of transport factors with their cargoes, regulatory factors, and specific nucleoporins.
Collapse
|
5
|
Sampathkumar P, Kim SJ, Manglicmot D, Bain KT, Gilmore J, Gheyi T, Phillips J, Pieper U, Fernandez-Martinez J, Franke JD, Matsui T, Tsuruta H, Atwell S, Thompson DA, Emtage JS, Wasserman SR, Rout MP, Sali A, Sauder JM, Almo SC, Burley SK. Atomic structure of the nuclear pore complex targeting domain of a Nup116 homologue from the yeast, Candida glabrata. Proteins 2012; 80:2110-6. [PMID: 22544723 PMCID: PMC3686472 DOI: 10.1002/prot.24102] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2012] [Revised: 04/05/2012] [Accepted: 04/11/2012] [Indexed: 01/07/2023]
Abstract
The nuclear pore complex (NPC), embedded in the nuclear envelope, is a large, dynamic molecular assembly that facilitates exchange of macromolecules between the nucleus and the cytoplasm. The yeast NPC is an eightfold symmetric annular structure composed of ~456 polypeptide chains contributed by ~30 distinct proteins termed nucleoporins. Nup116, identified only in fungi, plays a central role in both protein import and mRNA export through the NPC. Nup116 is a modular protein with N-terminal "FG" repeats containing a Gle2p-binding sequence motif and a NPC targeting domain at its C-terminus. We report the crystal structure of the NPC targeting domain of Candida glabrata Nup116, consisting of residues 882-1034 [CgNup116(882-1034)], at 1.94 Å resolution. The X-ray structure of CgNup116(882-1034) is consistent with the molecular envelope determined in solution by small-angle X-ray scattering. Structural similarities of CgNup116(882-1034) with homologous domains from Saccharomyces cerevisiae Nup116, S. cerevisiae Nup145N, and human Nup98 are discussed.
Collapse
|
6
|
Abstract
In eukaryotic cells, the spatial segregation of replication and transcription in the nucleus and translation in the cytoplasm imposes the requirement of transporting thousands of macromolecules between these two compartments. Nuclear pore complexes (NPCs) are the sole gateways that facilitate this macromolecular exchange across the nuclear envelope with the help of soluble transport receptors. Whereas the mobile transport machinery is reasonably well understood at the atomic level, a commensurate structural characterization of the NPC has only begun in the past few years. Here, we describe the recent progress toward the elucidation of the atomic structure of the NPC, highlight emerging concepts of its underlying architecture, and discuss key outstanding questions and challenges. The applied structure determination as well as the described design principles of the NPC may serve as paradigms for other macromolecular assemblies.
Collapse
Affiliation(s)
- André Hoelz
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, USA.
| | | | | |
Collapse
|
7
|
Structural and functional analysis of an essential nucleoporin heterotrimer on the cytoplasmic face of the nuclear pore complex. Proc Natl Acad Sci U S A 2011; 108:16571-6. [PMID: 21930948 DOI: 10.1073/pnas.1112846108] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
So far, only a few of the interactions between the ≈ 30 nucleoporins comprising the modular structure of the nuclear pore complex have been defined at atomic resolution. Here we report the crystal structure, at 2.6 Å resolution, of a heterotrimeric complex, composed of fragments of three cytoplasmically oriented nucleoporins of yeast: Nup82, Nup116, and Nup159. Our data show that the Nup82 fragment, representing more than the N-terminal half of the molecule, folds into an extensively decorated, seven-bladed β-propeller that forms the centerpiece of this heterotrimeric complex and anchors both a C-terminal fragment of Nup116 and the C-terminal tail of Nup159. Binding between Nup116 and Nup82 is mutually reinforced via two loops, one emanating from the Nup82 β-propeller and the other one from the β-sandwich fold of Nup116, each contacting binding pockets in their counterparts. The Nup82-Nup159 interaction occurs through an amphipathic α-helix of Nup159, which is cradled in a large hydrophobic groove that is generated from several large surface decorations of the Nup82 β-propeller. Although Nup159 and Nup116 fragments bind to the Nup82 β-propeller in close vicinity, there are no direct contacts between them, consistent with the noncooperative binding that was detected biochemically. Extensive mutagenesis delineated hot-spot residues for these interactions. We also showed that the Nup82 β-propeller binds to other yeast Nup116 family members, Nup145N, Nup100 and to the mammalian homolog, Nup98. Notably, each of the three nucleoporins contains additional nuclear pore complex binding sites, distinct from those that were defined here in the heterotrimeric Nup82•Nup159•Nup116 complex.
Collapse
|
8
|
Cross MK, Powers MA. Nup98 regulates bipolar spindle assembly through association with microtubules and opposition of MCAK. Mol Biol Cell 2011; 22:661-72. [PMID: 21209315 PMCID: PMC3046062 DOI: 10.1091/mbc.e10-06-0478] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
During mitosis, the nuclear pore complex is disassembled and, increasingly, nucleoporins are proving to have mitotic functions when released from the pore. We find a contribution of the nucleoporin Nup98 to mitotic spindle assembly through regulation of microtubule dynamics. When added to Xenopus extract spindle assembly assays, the C-terminal domain of Nup98 stimulates uncontrolled growth of microtubules. Conversely, inhibition or depletion of Nup98 leads to formation of stable monopolar spindles. Spindle bipolarity is restored by addition of purified, recombinant Nup98 C-terminus. The minimal required region of Nup98 corresponds to a portion of the C-terminal domain lacking a previously characterized function. We show association between this region of the C-terminus of Nup98 and both Taxol-stabilized microtubules and the microtubule-depolymerizing mitotic centromere-associated kinesin (MCAK). Importantly, we demonstrate that this domain of Nup98 inhibits MCAK depolymerization activity in vitro. These data support a model in which Nup98 interacts with microtubules and antagonizes MCAK activity, thus promoting bipolar spindle assembly.
Collapse
Affiliation(s)
- Marie K Cross
- Department of Cell Biology and Developmental Biology Graduate Program, Emory University School of Medicine, Atlanta, GA 30322, USA
| | | |
Collapse
|
9
|
Sampathkumar P, Ozyurt SA, Do J, Bain KT, Dickey M, Rodgers LA, Gheyi T, Sali A, Kim SJ, Phillips J, Pieper U, Fernandez-Martinez J, Franke JD, Martel A, Tsuruta H, Atwell S, Thompson DA, Emtage JS, Wasserman SR, Rout MP, Sauder JM, Burley SK. Structures of the autoproteolytic domain from the Saccharomyces cerevisiae nuclear pore complex component, Nup145. Proteins 2010; 78:1992-8. [PMID: 20310066 DOI: 10.1002/prot.22707] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Affiliation(s)
- Parthasarathy Sampathkumar
- New York SGX Research Center for Structural Genomics (NYSGXRC), Eli Lilly and Company, Lilly Biotechnology Center, San Diego, California 92121, USA.
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
10
|
Abstract
The spatial separation between the cytoplasm and the cell nucleus necessitates the continuous exchange of macromolecular cargo across the double-membraned nuclear envelope. Being the only passageway in and out of the nucleus, the nuclear pore complex (NPC) has the principal function of regulating the high throughput of nucleocytoplasmic transport in a highly selective manner so as to maintain cellular order and function. Here, we present a retrospective review of the evidence that has led to the current understanding of both NPC structure and function. Looking towards the future, we contemplate on how various outstanding effects and nanoscopic characteristics ought to be addressed, with the goal of reconciling structure and function into a single unified picture of the NPC.
Collapse
|
11
|
Lim RYH, Ullman KS, Fahrenkrog B. Biology and biophysics of the nuclear pore complex and its components. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2008; 267:299-342. [PMID: 18544502 DOI: 10.1016/s1937-6448(08)00632-1] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Nucleocytoplasmic exchange of proteins and ribonucleoprotein particles occurs via nuclear pore complexes (NPCs) that reside in the double membrane of the nuclear envelope (NE). Significant progress has been made during the past few years in obtaining better structural resolution of the three-dimensional architecture of NPC with the help of cryo-electron tomography and atomic structures of domains from nuclear pore proteins (nucleoporins). Biophysical and imaging approaches have helped elucidate how nucleoporins act as a selective barrier in nucleocytoplasmic transport. Nucleoporins act not only in trafficking of macromolecules but also in proper microtubule attachment to kinetochores, in the regulation of gene expression and signaling events associated with, for example, innate and adaptive immunity, development and neurodegenerative disorders. Recent research has also been focused on the dynamic processes of NPC assembly and disassembly that occur with each cell cycle. Here we review emerging results aimed at understanding the molecular arrangement of the NPC and how it is achieved, defining the roles of individual nucleoporins both at the NPC and at other sites within the cell, and finally deciphering how the NPC serves as both a barrier and a conduit of active transport.
Collapse
Affiliation(s)
- Roderick Y H Lim
- M.E. Müller Institute for Structural Biology, Biozentrum, University of Basel, Klingelbergstrasse 70, 4056 Basel, Switzerland
| | | | | |
Collapse
|
12
|
Ratner GA, Hodel AE, Powers MA. Molecular determinants of binding between Gly-Leu-Phe-Gly nucleoporins and the nuclear pore complex. J Biol Chem 2007; 282:33968-76. [PMID: 17897945 DOI: 10.1074/jbc.m707911200] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
The vertebrate nucleoporin Nup98 can be expressed in two distinct forms from differentially spliced mRNAs, either as a 98-kDa protein or as the 195-kDa Nup98/Nup96 polyprotein. Both forms undergo autoproteolytic processing to generate the 90-kDa Nup98 and either an 8-kDa tail or the nucleoporin Nup96. An equivalent cleavage event occurs in one yeast ortholog, Nup145, to produce Nup145N and Nup145C. We previously proposed that Nup145N, and possibly the other orthologs Nup116 and Nup100, might bind to Nup145C as demonstrated for Nup98 and Nup96. Here we have further investigated the interaction of both yeast and vertebrate Gly-Leu-Phe-Gly nucleoporins with the nuclear pore. We find that dynamic Nup98 binding can be recapitulated in vitro and that simultaneous translation and folding as a polyprotein are not required to allow subsequent binding between Nup98 and Nup96. We show that Nup145N and Nup145C do indeed bind to each other, and we have determined the dissociation constants for these interactions in vitro. Additionally, we characterize two sites of molecular interaction for each binding pair. Of the yeast orthologs, Nup116 binds far less robustly to Nup145C than does Nup145N, and Nup100 binding is barely detectable. Thus, we conclude that Nup116 and Nup100 likely use means of incorporation into the nuclear pore complex that are distinct from those used by Nup145N.
Collapse
Affiliation(s)
- Gary A Ratner
- Department of Cell Biology and Biochemistry, Emory University School of Medicine, 615 Michael Street, Atlanta, GA 30322, USA
| | | | | |
Collapse
|
13
|
Denning DP, Rexach MF. Rapid Evolution Exposes the Boundaries of Domain Structure and Function in Natively Unfolded FG Nucleoporins. Mol Cell Proteomics 2007; 6:272-82. [PMID: 17079785 DOI: 10.1074/mcp.m600309-mcp200] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Nucleoporins with phenylalanine-glycine repeats (FG Nups) function at the nuclear pore complex (NPC) to facilitate nucleocytoplasmic transport. In Saccharomyces cerevisiae, each FG Nup contains a large natively unfolded domain that is punctuated by FG repeats. These FG repeats are surrounded by hydrophilic amino acids (AAs) common to disordered protein domains. Here we show that the FG domain of Nups from human, fly, worm, and other yeast species is also enriched in these disorder-associated AAs, indicating that structural disorder is a conserved feature of FG Nups and likely serves an important role in NPC function. Despite the conservation of AA composition, FG Nup sequences from different species show extensive divergence. A comparison of the AA substitution rates of proteins with syntenic orthologs in four Saccharomyces species revealed that FG Nups have evolved at twice the rate of average yeast proteins with most substitutions occurring in sequences between FG repeats. The rapid evolution of FG Nups is poorly explained by parameters known to influence AA substitution rate, such as protein expression level, interactivity, and essentiality; instead their rapid evolution may reflect an intrinsic permissiveness of natively unfolded structures to AA substitutions. The overall lack of AA sequence conservation in FG Nups is sharply contrasted by discrete stretches of conserved sequences. These conserved sequences highlight known karyopherin and nucleoporin binding sites as well as other uncharacterized sites that may have important structural and functional properties.
Collapse
Affiliation(s)
- Daniel P Denning
- Department of Molecular, Cell, and Developmental Biology, University of California, Santa Cruz, California 95064, USA
| | | |
Collapse
|
14
|
Süel KE, Cansizoglu AE, Chook YM. Atomic resolution structures in nuclear transport. Methods 2006; 39:342-55. [PMID: 16938467 PMCID: PMC3471385 DOI: 10.1016/j.ymeth.2006.06.015] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2006] [Accepted: 06/28/2006] [Indexed: 11/17/2022] Open
Abstract
There are currently at least 53 structures of components of nuclear transport in the Protein Databank. In addition to providing critical insights into molecular mechanisms of nuclear transport, these atomic resolution structures provide a large body of information that could guide biochemical and cell biological analyses involving nuclear transport proteins. This paper catalogs 53 crystal and NMR structures of nuclear transport proteins, with the emphasis on providing information useful for mutagenesis and overexpression of recombinant proteins.
Collapse
Affiliation(s)
| | | | - Yuh Min Chook
- Corresponding author. Fax: +1 214 645 6166. (Y.M. Chook)
| |
Collapse
|
15
|
Current awareness on yeast. Yeast 2006. [DOI: 10.1002/yea.1314] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
|
16
|
Devos D, Dokudovskaya S, Williams R, Alber F, Eswar N, Chait BT, Rout MP, Sali A. Simple fold composition and modular architecture of the nuclear pore complex. Proc Natl Acad Sci U S A 2006; 103:2172-7. [PMID: 16461911 PMCID: PMC1413685 DOI: 10.1073/pnas.0506345103] [Citation(s) in RCA: 225] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2005] [Indexed: 11/18/2022] Open
Abstract
The nuclear pore complex (NPC) consists of multiple copies of approximately 30 different proteins [nucleoporins (nups)], forming a channel in the nuclear envelope that mediates macromolecular transport between the cytosol and the nucleus. With <5% of the nup residues currently available in experimentally determined structures, little is known about the detailed structure of the NPC. Here, we use a combined computational and biochemical approach to assign folds for approximately 95% of the residues in the yeast and vertebrate nups. These fold assignments suggest an underlying simplicity in the composition and modularity in the architecture of all eukaryotic NPCs. The simplicity in NPC composition is reflected in the presence of only eight fold types, with the three most frequent folds accounting for approximately 85% of the residues. The modularity in NPC architecture is reflected in its hierarchical and symmetrical organization that partitions the predicted nup folds into three groups: the transmembrane group containing transmembrane helices and a cadherin fold, the central scaffold group containing beta-propeller and alpha-solenoid folds, and the peripheral FG group containing predominantly the FG repeats and the coiled-coil fold. Moreover, similarities between structures in coated vesicles and those in the NPC support our prior hypothesis for their common evolutionary origin in a progenitor protocoatomer. The small number of predicted fold types in the NPC and their internal symmetries suggest that the bulk of the NPC structure has evolved through extensive motif and gene duplication from a simple precursor set of only a few proteins.
Collapse
Affiliation(s)
- Damien Devos
- *Departments of Biopharmaceutical Sciences and Pharmaceutical Chemistry and California Institute for Quantitative Biomedical Research, University of California, Mission Bay QB3, 1700 4th Street, Suite 503B, San Francisco, CA 94143-2552; and Laboratories of
| | | | | | - Frank Alber
- *Departments of Biopharmaceutical Sciences and Pharmaceutical Chemistry and California Institute for Quantitative Biomedical Research, University of California, Mission Bay QB3, 1700 4th Street, Suite 503B, San Francisco, CA 94143-2552; and Laboratories of
| | - Narayanan Eswar
- *Departments of Biopharmaceutical Sciences and Pharmaceutical Chemistry and California Institute for Quantitative Biomedical Research, University of California, Mission Bay QB3, 1700 4th Street, Suite 503B, San Francisco, CA 94143-2552; and Laboratories of
| | - Brian T. Chait
- Mass Spectrometry and Gaseous Ion Chemistry, The Rockefeller University, 1230 York Avenue, New York, NY 10021-6399
| | | | - Andrej Sali
- *Departments of Biopharmaceutical Sciences and Pharmaceutical Chemistry and California Institute for Quantitative Biomedical Research, University of California, Mission Bay QB3, 1700 4th Street, Suite 503B, San Francisco, CA 94143-2552; and Laboratories of
| |
Collapse
|