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Hosoe Y, Miyanoiri Y, Re S, Ochi S, Asahina Y, Kawakami T, Kuroda M, Mizuguchi K, Oda M. Structural dynamics of the N‐terminal
SH2
domain of
PI3K
in its free and
CD28
‐bound states. FEBS J 2022; 290:2366-2378. [PMID: 36282120 DOI: 10.1111/febs.16666] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Revised: 08/29/2022] [Accepted: 10/24/2022] [Indexed: 11/06/2022]
Abstract
Protein conformational changes with fluctuations are fundamental aspects of protein-protein interactions (PPIs); understanding these motions is required for the rational design of PPI-regulating compounds. Src homology 2 (SH2) domains are commonly found in adapter proteins involved in signal transduction and specifically bind to consensus motifs of proteins containing phosphorylated tyrosine (pY). Here, we analysed the interaction between the N-terminal SH2 domain (nSH2) of the regulatory subunit in phosphoinositide 3-kinase (PI3K) and the cytoplasmic region of the T-cell co-receptor, CD28, using NMR and molecular dynamics (MD) simulations. First, we assigned the backbone signals of nSH2 on 1 H-15 N heteronuclear single quantum coherence spectra in the absence or presence of the CD28 phosphopeptide, SDpYMNMTPRRPG. Chemical shift perturbation experiments revealed allosteric changes at the BC loop and the C-terminal region of nSH2 upon CD28 binding. NMR relaxation experiments showed a conformational exchange associated with CD28 binding in these regions. The conformational stabilisation of the C-terminal region correlated with the regulation of PI3K catalytic function. Further, using 19 F- and 31 P-labelled CD28 phosphopeptide, we analysed the structural dynamics of CD28 and demonstrated that the aromatic ring of the pY residue fluctuated between multiple conformations upon nSH2 binding. Our MD simulations largely explained the NMR results and the structural dynamics of nSH2 and CD28 in both bound and unbound states. Notably, in addition to its major conformation, we detected a minor conformation of nSH2 in the CD28 bound state that may explain the allosteric conformational change in the BC loop.
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Affiliation(s)
- Yuhi Hosoe
- Graduate School of Life and Environmental Sciences Kyoto Prefectural University Japan
| | | | - Suyong Re
- Artificial Intelligence Center for Health and Biomedical Research National Institutes of Biomedical Innovation, Health, and Nutrition Osaka Japan
| | - Saki Ochi
- Graduate School of Life and Environmental Sciences Kyoto Prefectural University Japan
| | - Yuya Asahina
- Institute for Protein Research Osaka University Japan
| | - Toru Kawakami
- Institute for Protein Research Osaka University Japan
| | - Masataka Kuroda
- Artificial Intelligence Center for Health and Biomedical Research National Institutes of Biomedical Innovation, Health, and Nutrition Osaka Japan
- Discovery Technology Laboratories Mitsubishi Tanabe Pharma Corporation Yokohama Japan
| | - Kenji Mizuguchi
- Institute for Protein Research Osaka University Japan
- Artificial Intelligence Center for Health and Biomedical Research National Institutes of Biomedical Innovation, Health, and Nutrition Osaka Japan
| | - Masayuki Oda
- Graduate School of Life and Environmental Sciences Kyoto Prefectural University Japan
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Ogawa S, Asawa Y, Iiyama M, Yoshimori A, Nakamura H, Oda M. Regulation of CD28 binding to SH2 domains of Grb2 and PI3K by trisubstituted carboranes for T-cell activation. Bioorg Med Chem Lett 2022; 78:129049. [DOI: 10.1016/j.bmcl.2022.129049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Revised: 10/22/2022] [Accepted: 11/03/2022] [Indexed: 11/09/2022]
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3
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Clayton NS, Fox M, Vicenté-Garcia JJ, Schroeder CM, Littlewood TD, Wilde JI, Krishnan K, Brown MJB, Crafter C, Mott HR, Owen D. Assembly of nuclear dimers of PI3K regulatory subunits is regulated by the Cdc42-activated tyrosine kinase ACK. J Biol Chem 2022; 298:101916. [PMID: 35429500 PMCID: PMC9127371 DOI: 10.1016/j.jbc.2022.101916] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Revised: 03/15/2022] [Accepted: 03/16/2022] [Indexed: 11/25/2022] Open
Abstract
Activated Cdc42-associated kinase (ACK) is an oncogenic nonreceptor tyrosine kinase associated with poor prognosis in several human cancers. ACK promotes proliferation, in part by contributing to the activation of Akt, the major effector of class 1A phosphoinositide 3-kinases (PI3Ks), which transduce signals via membrane phosphoinositol lipids. We now show that ACK also interacts with other key components of class 1A PI3K signaling, the PI3K regulatory subunits. We demonstrate ACK binds to all five PI3K regulatory subunit isoforms and directly phosphorylates p85α, p85β, p50α, and p55α on Tyr607 (or analogous residues). We found that phosphorylation of p85β promotes cell proliferation in HEK293T cells. We demonstrate that ACK interacts with p85α exclusively in nuclear-enriched cell fractions, where p85α phosphorylated at Tyr607 (pTyr607) also resides, and identify an interaction between pTyr607 and the N-terminal SH2 domain that supports dimerization of the regulatory subunits. We infer from this that ACK targets p110-independent p85 and further postulate that these regulatory subunit dimers undertake novel nuclear functions underpinning ACK activity. We conclude that these dimers represent a previously undescribed mode of regulation for the class1A PI3K regulatory subunits and potentially reveal additional avenues for therapeutic intervention.
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Affiliation(s)
- Natasha S Clayton
- Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
| | - Millie Fox
- Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
| | | | | | - Trevor D Littlewood
- Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
| | - Jonathon I Wilde
- GlaxoSmithKline Medicines Research Centre, Screening and Compound Profiling, Stevenage, Herts, United Kingdom
| | - Kadalmani Krishnan
- Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
| | - Murray J B Brown
- GlaxoSmithKline Medicines Research Centre, Screening and Compound Profiling, Stevenage, Herts, United Kingdom
| | - Claire Crafter
- Bioscience, Research and Early Development, Oncology R&D, AstraZeneca, Cambridge, United Kingdom
| | - Helen R Mott
- Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom.
| | - Darerca Owen
- Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom.
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Incorporation of Oxidized Phenylalanine Derivatives into Insulin Signaling Relevant Proteins May Link Oxidative Stress to Signaling Conditions Underlying Chronic Insulin Resistance. Biomedicines 2022; 10:biomedicines10050975. [PMID: 35625712 PMCID: PMC9138545 DOI: 10.3390/biomedicines10050975] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Revised: 04/19/2022] [Accepted: 04/20/2022] [Indexed: 12/12/2022] Open
Abstract
A link between oxidative stress and insulin resistance has been suggested. Hydroxyl free radicals are known to be able to convert phenylalanine (Phe) into the non-physiological tyrosine isoforms ortho- and meta-tyrosine (o-Tyr, m-Tyr). The aim of our study was to examine the role of o-Tyr and m-Tyr in the development of insulin resistance. We found that insulin-induced uptake of glucose was blunted in cultures of 3T3-L1 grown on media containing o- or m-Tyr. We show that these modified amino acids are incorporated into cellular proteins. We focused on insulin receptor substrate 1 (IRS-1), which plays a role in insulin signaling. The activating phosphorylation of IRS-1 was increased by insulin, the effect of which was abolished in cells grown in m-Tyr or o-Tyr media. We found that phosphorylation of m- or o-Tyr containing IRS-1 segments by insulin receptor (IR) kinase was greatly reduced, PTP-1B phosphatase was incapable of dephosphorylating phosphorylated m- or o-Tyr IRS-1 peptides, and the SH2 domains of phosphoinositide 3-kinase (PI3K) bound the o-Tyr IRS-1 peptides with greatly reduced affinity. According to our data, m- or o-Tyr incorporation into IRS-1 modifies its protein–protein interactions with regulating enzymes and effectors, thus IRS-1 eventually loses its capacity to play its role in insulin signaling, leading to insulin resistance.
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Ochi S, Iiyama M, Oda M. Interdomain interactions in Grb2 revealed by the conformational stability and CD28 binding analysis. Biophys Chem 2022; 284:106792. [DOI: 10.1016/j.bpc.2022.106792] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2022] [Revised: 02/27/2022] [Accepted: 03/01/2022] [Indexed: 11/02/2022]
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Cancer-associated mutations in the p85α N-terminal SH2 domain activate a spectrum of receptor tyrosine kinases. Proc Natl Acad Sci U S A 2021; 118:2101751118. [PMID: 34507989 PMCID: PMC8449365 DOI: 10.1073/pnas.2101751118] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/02/2021] [Indexed: 11/18/2022] Open
Abstract
Phosphoinositide 3-kinase activation typically occurs following stimulation by upstream receptor tyrosine kinases (RTKs), which alleviate p110α inhibition by p85α. p85α and p110α driver mutations have been reported to activate p110α by disrupting the inhibitory interface between p85α and p110α. This study revealed that driver mutations in the p85α N-terminal SH2 domain can enhance p110α activity by inducing the activation of multiple RTKs. Furthermore, combination treatment with RTK and AKT inhibitors provides synergistic therapeutic efficacy. This previously uncharacterized oncogenic mechanism presents the exploitable vulnerability of a class of p85α mutant tumors. The phosphoinositide 3-kinase regulatory subunit p85α is a key regulator of kinase signaling and is frequently mutated in cancers. In the present study, we showed that in addition to weakening the inhibitory interaction between p85α and p110α, a group of driver mutations in the p85α N-terminal SH2 domain activated EGFR, HER2, HER3, c-Met, and IGF-1R in a p110α-independent manner. Cancer cells expressing these mutations exhibited the activation of p110α and the AKT pathway. Interestingly, the activation of EGFR, HER2, and c-Met was attributed to the ability of driver mutations to inhibit HER3 ubiquitination and degradation. The resulting increase in HER3 protein levels promoted its heterodimerization with EGFR, HER2, and c-Met, as well as the allosteric activation of these dimerized partners; however, HER3 silencing abolished this transactivation. Accordingly, inhibitors of either AKT or the HER family reduced the oncogenicity of driver mutations. The combination of these inhibitors resulted in marked synergy. Taken together, our findings provide mechanistic insights and suggest therapeutic strategies targeting a class of recurrent p85α mutations.
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Iiyama M, Numoto N, Ogawa S, Kuroda M, Morii H, Abe R, Ito N, Oda M. Molecular interactions of the CTLA-4 cytoplasmic region with the phosphoinositide 3-kinase SH2 domains. Mol Immunol 2020; 131:51-59. [PMID: 33386150 DOI: 10.1016/j.molimm.2020.12.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2020] [Revised: 11/28/2020] [Accepted: 12/03/2020] [Indexed: 11/25/2022]
Abstract
During T-cell regulation, T-cell receptors and CD28 lead to signaling activation, while T-lymphocyte antigen 4 (CTLA-4) is known to lead to downregulation, similar to programmed cell death-1 (PD-1). In the cytoplasmic tails of CD28 and CTLA-4, phosphoinositide 3-kinase (PI3K) binds to the consensus sequence including phosphotyrosine via SH2 domains, N- and C-terminal SH2 domains (nSH2 and cSH2), of its regulatory subunit, p85. In this study, we determined the crystal structure of a CTLA-4-derived phosphopeptide in complex with a Cys-substituted mutant of cSH2, C656S/C659V/C670L, at a 1.1 Å resolution. Phosphotyrosine of the bound peptide is tightly accommodated by the residues Arg631, Arg649, Ser651, and Ser652, similar to the cSH2 wild-type recognition mode of CD28, as reported previously. Upon the Cys mutation, the cSH2 thermal stability increased while the CTLA-4 binding affinity slightly changed. The binding experiments also showed that the binding affinity of CTLA-4 by cSH2 was approximately two orders of magnitude lower than that of CD28. Similar to CD28 binding, the CTLA-4 binding affinity of nSH2 was lower than that of cSH2. The complex structure of nSH2 and CTLA-4 was modeled, and compared with the crystal structure of cSH2 mutant and CTLA-4. The difference in the binding affinity between CD28 and CTLA-4, along with the difference between nSH2 and cSH2, could be explained by the 3D structures, which would be closely correlated with the respective T-cell signaling.
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Affiliation(s)
- Momoka Iiyama
- Graduate School of Life and Environmental Sciences, Kyoto Prefectural University, 1-5 Hangi-cho, Shimogamo, Sakyo-ku, Kyoto 606-8522, Japan
| | - Nobutaka Numoto
- Medical Research Institute, Tokyo Medical and Dental University (TMDU), 1-5-45 Yushima Bunkyo-ku, Tokyo 113-8510, Japan
| | - Shuhei Ogawa
- Research Institute for Biomedical Sciences, Tokyo University of Science, 2669 Yamazaki, Noda, Chiba 278-0022, Japan
| | - Masataka Kuroda
- Laboratory of Bioinformatics, AI Center for Health and Biomedical Research, National Institutes of Biomedical Innovation, Health and Nutrition (NIBIOHN), 7-6-8 Saito-Asagi, Ibaraki, Osaka 567-0085, Japan; Discovery Technology Laboratories, Mitsubishi Tanabe Pharma Corporation, 1000 Kamoshida-cho, Aoba-ku, Yokohama, Kanagawa 227-0033, Japan
| | - Hisayuki Morii
- Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Central 6, 1-1-1 Higashi, Tsukuba, Ibaraki 305-0074, Japan
| | - Ryo Abe
- Research Institute for Biomedical Sciences, Tokyo University of Science, 2669 Yamazaki, Noda, Chiba 278-0022, Japan
| | - Nobutoshi Ito
- Medical Research Institute, Tokyo Medical and Dental University (TMDU), 1-5-45 Yushima Bunkyo-ku, Tokyo 113-8510, Japan
| | - Masayuki Oda
- Graduate School of Life and Environmental Sciences, Kyoto Prefectural University, 1-5 Hangi-cho, Shimogamo, Sakyo-ku, Kyoto 606-8522, Japan.
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Kim DW, Cho JY. Recent Advances in Allogeneic CAR-T Cells. Biomolecules 2020; 10:biom10020263. [PMID: 32050611 PMCID: PMC7072190 DOI: 10.3390/biom10020263] [Citation(s) in RCA: 63] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Revised: 02/07/2020] [Accepted: 02/07/2020] [Indexed: 12/19/2022] Open
Abstract
In recent decades, great advances have been made in the field of tumor treatment. Especially, cell-based therapy targeting tumor associated antigen (TAA) has developed tremendously. T cells were engineered to have the ability to attack tumor cells by generating CAR constructs consisting of genes encoding scFv, a co-stimulatory domain (CD28 or TNFRSF9), and CD247 signaling domains for T cell proliferation and activation. Principally, CAR-T cells are activated by recognizing TAA by scFv on the T cell surface, and then signaling domains inside cells connected by scFv are subsequently activated to induce downstream signaling pathways involving T cell proliferation, activation, and production of cytokines. Many efforts have been made to increase the efficacy and persistence and also to decrease T cell exhaustion. Overall, allogeneic and universal CAR-T generation has attracted much attention because of their wide and prompt usage for patients. In this review, we summarized the current techniques for generation of allogeneic and universal CAR-T cells along with their disadvantages and limitations that still need to be overcome.
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Jaber Chehayeb R, Boggon TJ. SH2 Domain Binding: Diverse FLVRs of Partnership. Front Endocrinol (Lausanne) 2020; 11:575220. [PMID: 33042028 PMCID: PMC7530234 DOI: 10.3389/fendo.2020.575220] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Accepted: 08/12/2020] [Indexed: 11/27/2022] Open
Abstract
The Src homology 2 (SH2) domain has a special role as one of the cornerstone examples of a "modular" domain. The interactions of this domain are very well-conserved, and have long been described as a bidentate, or "two-pronged plug" interaction between the domain and a phosphotyrosine (pTyr) peptide. Recent work has, however, highlighted unusual features of the SH2 domain that illustrate a greater diversity than was previously appreciated. In this review we discuss some of the novel and unusual characteristics across the SH2 family, including unusual peptide binding pockets, multiple pTyr recognition sites, recognition sites for unphosphorylated peptides, and recently identified variability in the conserved FLVR motif.
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Affiliation(s)
- Rachel Jaber Chehayeb
- Yale College, New Haven, CT, United States
- Department of Molecular Biophysics and Biochemistry, New Haven, CT, United States
| | - Titus J. Boggon
- Department of Molecular Biophysics and Biochemistry, New Haven, CT, United States
- Department of Pharmacology, New Haven, CT, United States
- Yale Cancer Center, Yale University, New Haven, CT, United States
- *Correspondence: Titus J. Boggon
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Hosoe Y, Numoto N, Inaba S, Ogawa S, Morii H, Abe R, Ito N, Oda M. Structural and functional properties of Grb2 SH2 dimer in CD28 binding. Biophys Physicobiol 2019; 16:80-88. [PMID: 30923665 PMCID: PMC6435016 DOI: 10.2142/biophysico.16.0_80] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Accepted: 01/30/2019] [Indexed: 01/06/2023] Open
Abstract
Growth factor receptor-bound protein 2 (Grb2) is an adaptor protein that plays a critical role in cellular signal transduction. It contains a central Src homology 2 (SH2) domain flanked by two Src homology 3 (SH3) domains. Binding of Grb2 SH2 to the cytoplasmic region of CD28, phosphorylated Tyr (pY) containing the peptide motif pY-X-N-X, is required for costimulatory signaling in T cells. In this study, we purified the dimer and monomer forms of Grb2 SH2, respectively, and analyzed their structural and functional properties. Size exclusion chromatography analysis showed that both dimer and monomer exist as stable states. Thermal stability analysis using circular dichroism showed that the dimer mostly dissociates into the monomer around 50°C. CD28 binding experiments showed that the affinity of the dimer to the phosphopeptide was about three fold higher than that of the monomer, possibly due to the avidity effect. The present crystal structure analysis of Grb2 SH2 showed two forms; one is monomer at 1.15 Å resolution, which is currently the highest resolution analysis, and another is dimer at 2.00 Å resolution. In the dimer structure, the C-terminal region, comprising residues 123–152, was extended towards the adjacent molecule, in which Trp121 was the hinge residue. The stable dimer purified using size exclusion chromatography would be due to the C-terminal helix “swapping”. In cases where a mutation caused Trp121 to be replaced by Ser in Grb2 SH2, this protein still formed dimers, but lost the ability to bind CD28.
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Affiliation(s)
- Yuhi Hosoe
- Graduate School of Life and Environmental Sciences, Kyoto Prefectural University, Kyoto 606-8522, Japan
| | - Nobutaka Numoto
- Medical Research Institute, Tokyo Medical and Dental University, Bunkyo-ku, Tokyo 113-8510, Japan
| | - Satomi Inaba
- Graduate School of Life and Environmental Sciences, Kyoto Prefectural University, Kyoto 606-8522, Japan.,Research & Utilization Division, Japan Synchrotron Radiation Research Institute, Sayo, Hyogo 679-5198, Japan
| | - Shuhei Ogawa
- Research Institute for Biomedical Sciences, Tokyo University of Science, Noda, Chiba 278-0022, Japan
| | - Hisayuki Morii
- College of Liberal Arts and Sciences, Tokyo Medical and Dental University, Ichikawa, Chiba 272-0827, Japan
| | - Ryo Abe
- Research Institute for Biomedical Sciences, Tokyo University of Science, Noda, Chiba 278-0022, Japan.,Present address: Strategic Innovation and Research Center, Teikyo University, Itabashi-ku, Tokyo 173-8605, Japan
| | - Nobutoshi Ito
- Medical Research Institute, Tokyo Medical and Dental University, Bunkyo-ku, Tokyo 113-8510, Japan
| | - Masayuki Oda
- Graduate School of Life and Environmental Sciences, Kyoto Prefectural University, Kyoto 606-8522, Japan
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Signal Transduction Via Co-stimulatory and Co-inhibitory Receptors. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1189:85-133. [PMID: 31758532 DOI: 10.1007/978-981-32-9717-3_4] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
T-cell receptor (TCR)-mediated antigen-specific stimulation is essential for initiating T-cell activation. However, signaling through the TCR alone is not sufficient for inducing an effective response. In addition to TCR-mediated signaling, signaling through antigen-independent co-stimulatory or co-inhibitory receptors is critically important not only for the full activation and functional differentiation of T cells but also for the termination and suppression of T-cell responses. Many studies have investigated the signaling pathways underlying the function of each molecular component. Co-stimulatory and co-inhibitory receptors have no kinase activity, but their cytoplasmic region contains unique functional motifs and potential phosphorylation sites. Engagement of co-stimulatory receptors leads to recruitment of specific binding partners, such as adaptor molecules, kinases, and phosphatases, via recognition of a specific motif. Consequently, each co-stimulatory receptor transduces a unique pattern of signaling pathways. This review focuses on our current understanding of the intracellular signaling pathways provided by co-stimulatory and co-inhibitory molecules, including B7:CD28 family members, immunoglobulin, and members of the tumor necrosis factor receptor superfamily.
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Shiota A, Inaba S, Oda M. Effects of active site residues of 3α-hydroxysteroid dehydrogenase from pseudomonas sp. b-0831 on its catalysis and cofactor binding. Biosci Biotechnol Biochem 2018; 82:1702-1707. [DOI: 10.1080/09168451.2018.1486175] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
Abstract
ABSTRACT
We overexpressed and purified 3α-hydroxysteroid dehydrogenase from Pseudomonas sp. B-0831 (Ps3αHSD) and its mutants where the active site residues known as the SYK triad, Ser114, Tyr153, and Lys157, were mutated. Ps3αHSD catalyzes the reaction by using a nucleotide cofactor. The NADH binding affinity of K157A mutant was much lower than that of the wild-type, mainly due to loss of a hydrogen bond. The decreased affinity would result in decreased kcat. Compared to the wild-type, the mutants S114A and Y153F showed higher Km and lower kcat values in both oxidation and reduction reactions. Simultaneous mutation of S114A and Y153F resulted in a significant decrease in kcat relative to the single mutant. These results are supported by the notion that Tyr153 is a catalytic base and Ser114 would be a substitute. Loss of hydrogen bonding with NADH upon the Y153F mutation resulted in increased enthalpy change, partially compensated by increased entropy change.
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Affiliation(s)
- Ayako Shiota
- Graduate School of Life and Environmental Sciences, Kyoto Prefectural University, Kyoto, Japan
| | - Satomi Inaba
- Graduate School of Life and Environmental Sciences, Kyoto Prefectural University, Kyoto, Japan
- Research & Utilization Division, Japan Synchrotron Radiation Research Institute, Hyogo, Japan
| | - Masayuki Oda
- Graduate School of Life and Environmental Sciences, Kyoto Prefectural University, Kyoto, Japan
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Structural Basis for Regulation of Phosphoinositide Kinases and Their Involvement in Human Disease. Mol Cell 2018; 71:653-673. [DOI: 10.1016/j.molcel.2018.08.005] [Citation(s) in RCA: 117] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2018] [Revised: 06/22/2018] [Accepted: 07/30/2018] [Indexed: 01/09/2023]
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14
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Peptide Scaffold-Based Discovery of Nonpeptide Natural Medicines to Target PI3K p85 SH2 Domain. Int J Pept Res Ther 2017. [DOI: 10.1007/s10989-017-9591-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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