Dynamic conformations of nucleophosmin (NPM1) at a key monomer-monomer interface affect oligomer stability and interactions with granzyme B.
Nucleophosmin (NPM1) is an abundant, nucleolar tumor antigen with important roles in cell proliferation and putative contributions to oncogenesis. Wild-type NPM1 forms pentameric oligomers through interactions at the amino-terminal core domain. A truncated form of NPM1 found in some hepatocellular c...
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| Format: | Article |
| Language: | English |
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Public Library of Science (PLoS)
2014-01-01
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| Series: | PLoS ONE |
| Online Access: | http://europepmc.org/articles/PMC4260957?pdf=render |
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| author | Wei D Duan-Porter Virgil L Woods Kimberly D Maurer Sheng Li Antony Rosen |
| author_facet | Wei D Duan-Porter Virgil L Woods Kimberly D Maurer Sheng Li Antony Rosen |
| author_sort | Wei D Duan-Porter |
| collection | DOAJ |
| description | Nucleophosmin (NPM1) is an abundant, nucleolar tumor antigen with important roles in cell proliferation and putative contributions to oncogenesis. Wild-type NPM1 forms pentameric oligomers through interactions at the amino-terminal core domain. A truncated form of NPM1 found in some hepatocellular carcinoma tissue formed an unusually stable oligomer and showed increased susceptibility to cleavage by granzyme B. Initiation of translation at the seventh methionine generated a protein (M7-NPM) that shared all these properties. We used deuterium exchange mass spectrometry (DXMS) to perform a detailed structural analysis of wild-type NPM1 and M7-NPM, and found dynamic conformational shifts or local "unfolding" at a specific monomer-monomer interface which included the β-hairpin "latch." We tested the importance of interactions at the β-hairpin "latch" by replacing a conserved tyrosine in the middle of the β-hairpin loop with glutamic acid, generating Y67E-NPM. Y67E-NPM did not form stable oligomers and further, prevented wild-type NPM1 oligomerization in a dominant-negative fashion, supporting the critical role of the β-hairpin "latch" in monomer-monomer interactions. Also, we show preferential cleavage by granzyme B at one of two available aspartates (either D161 or D122) in M7-NPM and Y67E-NPM, whereas wild-type NPM1 was cleaved at both sites. Thus, we observed a correlation between the propensity to form oligomers and granzyme B cleavage site selection in nucleophosmin proteins, suggesting that a small change at an important monomer-monomer interface can affect conformational shifts and impact protein-protein interactions. |
| first_indexed | 2024-12-20T18:39:32Z |
| format | Article |
| id | doaj.art-1660dcb2ff414622a0eb162c5326c6d4 |
| institution | Directory Open Access Journal |
| issn | 1932-6203 |
| language | English |
| last_indexed | 2024-12-20T18:39:32Z |
| publishDate | 2014-01-01 |
| publisher | Public Library of Science (PLoS) |
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| series | PLoS ONE |
| spelling | doaj.art-1660dcb2ff414622a0eb162c5326c6d42022-12-21T19:29:51ZengPublic Library of Science (PLoS)PLoS ONE1932-62032014-01-01912e11506210.1371/journal.pone.0115062Dynamic conformations of nucleophosmin (NPM1) at a key monomer-monomer interface affect oligomer stability and interactions with granzyme B.Wei D Duan-PorterVirgil L WoodsKimberly D MaurerSheng LiAntony RosenNucleophosmin (NPM1) is an abundant, nucleolar tumor antigen with important roles in cell proliferation and putative contributions to oncogenesis. Wild-type NPM1 forms pentameric oligomers through interactions at the amino-terminal core domain. A truncated form of NPM1 found in some hepatocellular carcinoma tissue formed an unusually stable oligomer and showed increased susceptibility to cleavage by granzyme B. Initiation of translation at the seventh methionine generated a protein (M7-NPM) that shared all these properties. We used deuterium exchange mass spectrometry (DXMS) to perform a detailed structural analysis of wild-type NPM1 and M7-NPM, and found dynamic conformational shifts or local "unfolding" at a specific monomer-monomer interface which included the β-hairpin "latch." We tested the importance of interactions at the β-hairpin "latch" by replacing a conserved tyrosine in the middle of the β-hairpin loop with glutamic acid, generating Y67E-NPM. Y67E-NPM did not form stable oligomers and further, prevented wild-type NPM1 oligomerization in a dominant-negative fashion, supporting the critical role of the β-hairpin "latch" in monomer-monomer interactions. Also, we show preferential cleavage by granzyme B at one of two available aspartates (either D161 or D122) in M7-NPM and Y67E-NPM, whereas wild-type NPM1 was cleaved at both sites. Thus, we observed a correlation between the propensity to form oligomers and granzyme B cleavage site selection in nucleophosmin proteins, suggesting that a small change at an important monomer-monomer interface can affect conformational shifts and impact protein-protein interactions.http://europepmc.org/articles/PMC4260957?pdf=render |
| spellingShingle | Wei D Duan-Porter Virgil L Woods Kimberly D Maurer Sheng Li Antony Rosen Dynamic conformations of nucleophosmin (NPM1) at a key monomer-monomer interface affect oligomer stability and interactions with granzyme B. PLoS ONE |
| title | Dynamic conformations of nucleophosmin (NPM1) at a key monomer-monomer interface affect oligomer stability and interactions with granzyme B. |
| title_full | Dynamic conformations of nucleophosmin (NPM1) at a key monomer-monomer interface affect oligomer stability and interactions with granzyme B. |
| title_fullStr | Dynamic conformations of nucleophosmin (NPM1) at a key monomer-monomer interface affect oligomer stability and interactions with granzyme B. |
| title_full_unstemmed | Dynamic conformations of nucleophosmin (NPM1) at a key monomer-monomer interface affect oligomer stability and interactions with granzyme B. |
| title_short | Dynamic conformations of nucleophosmin (NPM1) at a key monomer-monomer interface affect oligomer stability and interactions with granzyme B. |
| title_sort | dynamic conformations of nucleophosmin npm1 at a key monomer monomer interface affect oligomer stability and interactions with granzyme b |
| url | http://europepmc.org/articles/PMC4260957?pdf=render |
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